@article{boone_amma_2009,
	title = {The {AMMA} {Land} {Surface} {Model} {Intercomparison} {Project} ({ALMIP})},
	volume = {90},
	copyright = {American Meteorological Society},
	url = {http://journals.ametsoc.org/doi/abs/10.1175/2009BAMS2786.1},
	doi = {10.1175/2009BAMS2786.1},
	number = {12},
	journal = {Bulletin of the American Meteorological Society},
	author = {Boone, Aaron and Decharme, Bertrand and Guichard, Françoise and de Rosnay, Patricia and Balsamo, Gianpaolo and Beljaars, Anton and Chopin, Franck and Orgeval, Tristan and Polcher, Jan and Delire, Christine and Ducharne, Agnes and Gascoin, Simon and Grippa, Manuela and Jarlan, Lionel and Kergoat, Laurent and Mougin, Eric and Gusev, Yeugeniy and Nasonova, Olga and Harris, Phil and Taylor, Christopher and Norgaard, Anette and Sandholt, Inge and Ottlé, Catherine and Poccard-Leclercq, Isabelle and Saux-Picart, Stephane and Xue, Yongkang},
	year = {2009},
	keywords = {AMMA-CATCH, ao},
	pages = {1865--1880},
}

@article{boulain_towards_2009,
	title = {Towards an understanding of coupled physical and biological processes in the cultivated {Sahel} - 2. {Vegetation} and carbon dynamics},
	volume = {375},
	issn = {0022-1694},
	url = {DOI: 10.1016/j.jhydrol.2008.11.045},
	doi = {10.1016/j.jhydrol.2008.11.045},
	abstract = {This paper analyses the dynamics of vegetation and carbon during the West African monsoon season, for millet crop and fallow vegetation covers in the cultivated area of the Sahel. Comparing these two dominant land cover types informs on the impact of cultivation on productivity and carbon fluxes. Biomass, leaf area index (LAI) and carbon fluxes were monitored over a 2-year period for these two vegetation systems in the Wankama catchment of the AMMA (African monsoon multidisciplinary analyses) experimental super-site in West Niger. Carbon fluxes and water use efficiency observed at the field scale are confronted with ecophysiological measurements (photosynthetic response to light, and relation of water use efficiency to air humidity) made at the leaf scale for the dominant plant species in the two vegetation systems. The two rainy seasons monitored were dissimilar with respect to rain patterns, reflecting some of the interannual variability. Distinct responses in vegetation development and in carbon dynamics were observed between the two vegetation systems. Vegetation development in the fallow was found to depend more on rainfall distribution along the season than on its starting date. A quite opposite behaviour was observed for the crop vegetation: the date of first rain appears as a principal factor of millet growth. Carbon flux exchanges were well correlated to vegetation development. High responses of photosynthesis to light were observed for the dominant herbaceous and shrub species of the fallow at the leaf and field scales. Millet showed high response at the leaf scale, but a much lesser response at the field scale. This pattern, also observed for water use efficiency, is to be related to the low density of the millet cover. A simple LAI-based model for scaling up the photosynthetic response from leaf to field scale was found quite successful for the fallow, but was less conclusive for the crop, due to spatial variability of LAI. Time/space variations in leaf distribution for the dominant species are key to scale transition of carbon dynamics. Results obtained for the two vegetation covers are important in light of the major land use/cover change experienced in the Sahel region due to extensive savanna clearing for food production. (C) 2008 Elsevier B.V. All rights reserved.},
	number = {1-2},
	journal = {Journal of Hydrology},
	author = {Boulain, N. and Cappelaere, B. and Ramier, D. and Issoufou, H.B.A. and Halilou, O. and Seghieri, J. and Guillemin, F. and O{\textbackslash}H{\textbackslash}i, M. and Gignoux, J. and Timouk, F.},
	month = aug,
	year = {2009},
	keywords = {West Africa, Assimilation, Carbon dioxide, Fallow savanna, Millet, Respiration, AMMA-CATCH, niger},
	pages = {190--203},
}

@article{cappelaere_hydrologic_2003,
	title = {Hydrologic process simulation of a semiarid, endoreic catchment in {Sahelian} {West} {Niger}. 2. {Model} calibration and uncertainty characterization},
	volume = {279},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/pii/S0022169403001823},
	doi = {10.1016/S0022-1694(03)00182-3},
	abstract = {The Wankama endoreic system in the region of Niamey (Niger), monitored over the period 1992–2000, is studied with r.water.fea, a physically-based, spatially-distributed rainfall–runoff model. Catchment characteristics and data, together with model principles and construction, are described in Peugeot et al. [J. Hydrol., 2003], who used the uncalibrated model as one of several investigation tools for the screening of rainfall–runoff observations. This second paper focuses on model calibration and verification, namely the methods and criteria used to that end followed by the results thereby obtained. Based on a diagnostic function that combines errors in runoff volumes and in peak discharges, calibration is performed by exploring a 3D parameter space. A resampling-based cross-validation technique is used to investigate calibration stability with respect to data sample fluctuations, and to assess the predictive capabilities of the calibrated model. The issues of parameter uncertainty, sample representativeness, and presence of influential observations, are discussed. An empirical, non-parametric method is devised to characterize parameter uncertainty and to assign intervals to volume predictions. Model verification is performed against the data from the last two seasons. Internal catchment behavior, as produced by the model, appears qualitatively consistent with field information, including a weak upper-area contribution to catchment outflow due to large runoff abstraction by the conveying hydrographic network.},
	language = {en},
	number = {1-4},
	journal = {Journal of Hydrology},
	author = {Cappelaere, Bernard and Vieux, Baxter E. and Peugeot, Christophe and Maia, Ana and Séguis, Luc},
	month = aug,
	year = {2003},
	keywords = {Africa, Calibration, Channel infiltration, Distributed hydrologic modeling, Hortonian runoff, Sahel, Uncertainty, AMMA-CATCH},
	pages = {244--261},
}

@article{descroix_change_2012,
	title = {Change in {Sahelian} {Rivers} hydrograph: {The} case of recent red floods of the {Niger} {River} in the {Niamey} region},
	volume = {98–99},
	issn = {0921-8181},
	url = {http://www.sciencedirect.com/science/article/pii/S092181811200149X},
	doi = {10.1016/j.gloplacha.2012.07.009},
	abstract = {Changes in the hydrological regime of Sahelian Rivers are considered based upon the example of the Middle Niger River and its exceptional flood in 2010 near the city of Niamey. It is shown that rainfall in 2010 was only average with respect to the long term record, with neither the monthly rainfall distribution in terms of the amount of rainfall nor the distribution of rainy events changing significantly in the last few decades. Particularly, no increase in the number of extreme rainfall events is observed. In spite of this, the Niger River's right bank tributaries have shown a sharp increase in runoff since the 1970s, which is still ongoing, and has resulted in a modification of the Niger River's regime from a single hydrograph to a two flood hydrograph, the local flood, occurring during the rainy season being the more pronounced one. This modification is likely due to an increase of bare soils and crusted soil areas as a consequence of human pressure, resulting mostly from the spatial extension of crop areas and the shortening of fallow periods. Changes in connectivity of the river networks on both banks of the Niger such as endorheism bursting events also caused an increase in the contributing basin area. Policy makers should be alerted to the effects of intensive cropping, land clearing and overgrazing in some areas, on the hydrological regimes of Sahelian Rivers.},
	language = {English},
	journal = {Global and Planetary Change},
	author = {Descroix, Luc and Genthon, Pierre and Amogu, Okechukwu and Rajot, Jean-Louis and Sighomnou, Daniel and Vauclin, Michel},
	month = dec,
	year = {2012},
	keywords = {West Africa, endorheism bursting, land use change, monsoon, red flood, soil crusting, rainfall, AMMA-CATCH, climate-change, HYBIS, Monsoon, burkina-faso, desertification, west-africa, variability, Vegetation dynamics, soil-moisture, Land use change, northern mexico, water},
	pages = {18--30},
}

@article{descroix_spatio-temporal_2009,
	title = {Spatio-temporal variability of hydrological regimes around the boundaries between {Sahelian} and {Sudanian} areas of {West} {Africa} : a synthesis},
	volume = {375},
	issn = {0022-1694},
	shorttitle = {Spatio-temporal variability of hydrological regimes around the boundaries between {Sahelian} and {Sudanian} areas of {West} {Africa}},
	url = {10.1016/j.jhydrol.2008.12.012},
	doi = {10.1016/j.jhydrol.2008.12.012},
	abstract = {Abundant information is available on West African drought and its hydrological and environmental impacts. Land-use and climatic changes have greatly modified the conditions of Sudanian and Sahelian hydrology, impacting the regime and discharge of the main rivers. Human pressure on the environment (significant increase in crops and disappearance of natural bushes and landscapes, for example) has led to severe soil crusting and desertification throughout Sahelian regions. Despite recent increases in rainfall, the drought has not ended, resulting in two different hydrological evolutions. In the Sudanian areas, stream flows have been reduced, sometimes as much as twice the rainfall reduction rate. In the Sahelian regions, runoff coefficients have increased to such a degree that discharges are increasing, in spite of the reduced rainfall. The main goal of this paper is to synthesize the recent advances in the Sahelian and Sudano-Sahelian West African hydrology. The other objectives are two fold: First, to discuss the Sahelian Paradox (the increase in runoff in most of the Sahel during the drought, at least during the 1968-1995 period, as described in the 1980s) and paradox of groundwater highlighted in the square degree of Niamey (the rise in water table levels in some endorheic areas during the same drought, evidenced in the 1990s), and second, to attempt to define the application of their respective geographical areas. The land-use changes act as a general factor of hydrological evolution of soils and basins, while some spatial factors explain the great variability in the response to environmental evolution, such as endorheism, geological context, latitudinal climate gradient, and local hydrodynamic behaviour of environment. This paper is literature-based, and incorporates current research advances in the field, as well as a prospective focused on resources and socio-economic impacts.},
	number = {1-2},
	journal = {Journal of Hydrology},
	author = {Descroix, Luc and Mahé, Gil and Lebel, Thierry and Favreau, Guillaume and Galle, Sylvie and Gautier, E. and Olivry, J. C. and Albergel, Jean and Amogu, O. and Cappelaere, Bernard and Dessouassi, R. and Diedhiou, Arona and Le Breton, E. and Mamadou, I. and Sighomnou, D.},
	month = aug,
	year = {2009},
	keywords = {West Africa, Hortonian runoff, AMMA-CATCH, HYBIS, ao, Endoreism, Land-use change, Sahelian climate, Scale effect},
	pages = {90--102},
}

@article{favreau_estimate_2002,
	title = {Estimate of {Recharge} of a {Rising} {Water} {Table} in {Semiarid} {Niger} from {3H} and {14C} {Modeling}},
	volume = {40},
	issn = {1745-6584},
	url = {http://doi.wiley.com/10.1111/j.1745-6584.2002.tb02499.x},
	doi = {10.1111/j.1745-6584.2002.tb02499.x},
	language = {en},
	number = {2},
	journal = {Ground Water},
	author = {Favreau, Guillaume and Leduc, Christian and Marlin, Christelle and Dray, Martial and Taupin, Jean-Denis and Massault, Marc and Le Gal La Salle, Corinne and Babic, Milanka},
	month = mar,
	year = {2002},
	keywords = {AMMA-CATCH},
	pages = {144--151},
}

@article{galle_amma-catch_2018,
	title = {{AMMA}-{CATCH}, a {Critical} {Zone} {Observatory} in {West} {Africa} {Monitoring} a {Region} in {Transition}},
	volume = {17},
	issn = {1539-1663},
	url = {http://dx.doi.org/10.2136/vzj2018.03.0062},
	doi = {10.2136/vzj2018.03.0062},
	abstract = {West Africa is a region in fast transition from climate, demography, and land use perspectives. In this context, the African Monsoon Multidisciplinary Analysis (AMMA)–Couplage de l'Atmosphère Tropicale et du Cycle eco-Hydrologique (CATCH) long-term regional observatory was developed to monitor the impacts of global change on the critical zone of West Africa and to better understand its current and future dynamics. The observatory is organized into three thematic axes, which drive the observation and instrumentation strategy: (i) analyze the long-term evolution of eco-hydrosystems from a regional perspective; (ii) better understand critical zone processes and their variability; and (iii) meet socioeconomic and development needs. To achieve these goals, the observatory has gathered data since 1990 from four densely instrumented mesoscale sites (∼104 km2 each), located at different latitudes (Benin, Niger, Mali, and Senegal) so as to sample the sharp eco-climatic gradient that is characteristic of the region. Simultaneous monitoring of the vegetation cover and of various components of the water balance at these four sites has provided new insights into the seemingly paradoxical eco-hydrological changes observed in the Sahel during the last decades: groundwater recharge and/or runoff intensification despite rainfall deficit and subsequent re-greening with still increasing runoff. Hydrological processes and the role of certain key landscape features are highlighted, as well as the importance of an appropriate description of soil and subsoil characteristics. Applications of these scientific results for sustainable development issues are proposed. Finally, detecting and attributing eco-hydrological changes and identifying possible regime shifts in the hydrologic cycle are the next challenges that need to be faced.},
	language = {English},
	number = {1},
	journal = {Vadose Zone Journal},
	author = {Galle, S. and Grippa, M. and Peugeot, C. and Moussa, I. Bouzou and Cappelaere, B. and Demarty, J. and Mougin, E. and Panthou, G. and Adjomayi, P. and Agbossou, E.K. and Ba, A. and Boucher, M. and Cohard, J.-M. and Descloitres, M. and Descroix, L. and Diawara, M. and Dossou, M. and Favreau, G. and Gangneron, F. and Gosset, M. and Hector, B. and Hiernaux, P. and Issoufou, B.-A. and Kergoat, L. and Lawin, E. and Lebel, T. and Legchenko, A. and Abdou, M. Malam and Malam-Issa, O. and Mamadou, O. and Nazoumou, Y. and Pellarin, T. and Quantin, G. and Sambou, B. and Seghieri, J. and Séguis, L. and Vandervaere, J.-P. and Vischel, T. and Vouillamoz, J.-M. and Zannou, A. and Afouda, S. and Alhassane, A. and Arjounin, M. and Barral, H. and Biron, R. and Cazenave, F. and Chaffard, V. and Chazarin, J.-P. and Guyard, H. and Koné, A. and Mainassara, I. and Mamane, A. and Oi, M. and Ouani, T. and Soumaguel, N. and Wubda, M. and Ago, E.E. and Alle, I.C. and Allies, A. and Arpin-Pont, F. and Awessou, B. and Cassé, C. and Charvet, G. and Dardel, C. and Depeyre, A. and Diallo, F.B. and Do, T. and Fatras, C. and Frappart, F. and Gal, L. and Gascon, T. and Gibon, F. and Guiro, I. and Ingatan, A. and Kempf, J. and Kotchoni, D.O.V. and Lawson, F.M.A. and Leauthaud, C. and Louvet, S. and Mason, E. and Nguyen, C.C. and Perrimond, B. and Pierre, C. and Richard, A. and Robert, E. and Román-Cascón, C. and Velluet, C. and Wilcox, C.},
	year = {2018},
	keywords = {AMMA-CATCH, LMI REZOC, OZCAR, Benin, Niger, Mali, AO, PHYREV, synthesis},
	pages = {180062},
}

@article{gash_hapex-sahelthe_1997,
	title = {{HAPEX}-{SahelThe} variability of evaporation during the {HAPEX}-{Sahel} {Intensive} {Observation} {Period}},
	volume = {188-189},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/pii/S0022169496031678},
	doi = {10.1016/S0022-1694(96)03167-8},
	abstract = {The variation in evaporative fraction and actual evaporation is examined for three sample days in the HAPEX-Sahel Intensive Observation Period (IOP), including data from all the vegetation types and sites. The trends in evaporative fraction over the IOP are also presented for eight sites. The high rate of evaporation from bare soil in the days following rainfall produces a variability in evaporation which makes differences between sites difficult to interpret on a day-to-day basis, but over the whole IOP it is shown that the millet uses a smaller proportion of the available energy for evaporation than the tiger bush or fallow savannah. The combined effect of differences in the total energy used and its partitioning into evaporation and sensible heat flux is demonstrated from the trends in cumulative total energy use and evaporation at the three southern sites, where it is shown that there is systematically less evaporation from the millet than from the savannah or tiger bush sites.},
	language = {en},
	journal = {Journal of Hydrology},
	author = {Gash, J. H. C. and Kabat, P. and Monteny, B. A. and Amadou, M. and Bessemoulin, P. and Billing, H. and Blyth, E. M. and deBruin, H. A. R. and Elbers, J. A. and Friborg, T. and Harrison, G. and Holwill, C. J. and Lloyd, C. R. and Lhomme, J. P. and Moncrieff, J. B. and Puech, D. and Soegaard, H. and Taupin, J. D. and Tuzet, A. and Verhoef, A.},
	month = feb,
	year = {1997},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {385--399},
}

@article{getirana_evaluating_2014,
	title = {Evaluating {LSM}-{Based} {Water} {Budgets} over a {West} {African} {Basin} {Assisted} with a {River} {Routing} {Scheme}},
	volume = {15},
	url = {http://journals.ametsoc.org/doi/abs/10.1175/JHM-D-14-0012.1},
	doi = {10.1175/JHM-D-14-0012.1},
	abstract = {AbstractWithin the framework of the African Monsoon Multidisciplinary Analysis (AMMA) Land Surface Model Intercomparison Project phase 2 (ALMIP-2), this study evaluates the water balance simulated by the Interactions between Soil, Biosphere, and Atmosphere (ISBA) over the upper Ouémé River basin, in Benin, using a mesoscale river routing scheme (RRS). The RRS is based on the nonlinear Muskingum–Cunge method coupled with two linear reservoirs that simulate the time delay of both surface runoff and base flow that are produced by land surface models. On the basis of the evidence of a deep water-table recharge in that region, a reservoir representing the deep-water infiltration (DWI) is introduced. The hydrological processes of the basin are simulated for the 2005–08 AMMA field campaign period during which rainfall and streamflow data were intensively collected over the study area. Optimal RRS parameter sets were determined for three optimization experiments that were performed using daily streamflow at five gauges within the basin. Results demonstrate that the RRS simulates streamflow at all gauges with relative errors varying from −20\% to 3\% and Nash–Sutcliffe coefficients varying from 0.62 to 0.90. DWI varies from 24\% to 67\% of the base flow as a function of the subbasin. The relatively simple reservoir DWI approach is quite robust, and further improvements would likely necessitate more complex solutions (e.g., considering seasonality and soil type in ISBA); thus, such modifications are recommended for future studies. Although the evaluation shows that the simulated streamflows are generally satisfactory, further field investigations are necessary to confirm some of the model assumptions.},
	language = {en},
	number = {6},
	journal = {Journal of Hydrometeorology},
	author = {Getirana, Augusto C. V. and Boone, Aaron and Peugeot, Christophe},
	month = dec,
	year = {2014},
	keywords = {Africa, Hydrologic models, Land surface model, Model evaluation/performance, Parameterization, AMMA-CATCH},
	pages = {2331--2346},
}

@article{guyot_long-term_2012,
	title = {Long-term observations of turbulent fluxes over heterogeneous vegetation using scintillometry and additional observations: {A} contribution to {AMMA} under {Sudano}-{Sahelian} climate},
	volume = {154-155},
	issn = {0168-1923},
	shorttitle = {Long-term observations of turbulent fluxes over heterogeneous vegetation using scintillometry and additional observations},
	url = {http://www.sciencedirect.com/science/article/pii/S0168192311003078},
	doi = {10.1016/j.agrformet.2011.10.008},
	abstract = {Based on a 3-year period of infrared scintillometry, soil and meteorological measurements, this study presents an analysis of the surface energy balance partitioning over a heterogeneous savannah, in the Sudano-Sahelian region. The site is located in Northern Benin, meso-site of the African Monsoon Multidisciplinary Analyses (AMMA) project. The 3-year period enables an analysis of several alternate dry and wet periods, as well as the intermediate dry-to-wet and wet-to-dry periods. Infrared scintillometry, coupled with measurements of the available energy (net radiation minus ground heat flux) and a careful analysis of the aerodynamic properties of the scintillometer footprint, are employed to provide robust estimates of the turbulent (sensible and latent heat) fluxes over complex terrain, in terms of the topography and in terms of the spatially and temporally heterogeneous vegetation cover. A characterization of the uncertainties on each term of the energy balance is given at the scale of the scintillometer footprint. These uncertainties strongly depend on the season for the residual latent heat flux. Results point out that the climate of the Sudano-Sahelian region is characterized by a strong seasonal cycle and inter-annual variability, related to changing atmospheric and land surface conditions. The evaporative fraction is found to be relatively constant during the wet period (0.67) and more variable during the dry and intermediate periods. In addition, sensible heat flux and net radiation are well correlated during the dry season. The diurnal cycle shows a predominance of evaporation during the wet season and sensible heat during the dry season. Results point a significant latent heat flux during the dry period, signature of persistent vegetation in the Sudano-Sahelian region. Finally, that data set at hourly time step would provide useful information for modelling and the parameterization of the associated processes for this region.},
	number = {0},
	journal = {Agricultural and Forest Meteorology},
	author = {Guyot, Adrien and Cohard, Jean-Martial and Anquetin, Sandrine and Galle, Sylvie},
	month = mar,
	year = {2012},
	keywords = {Energy balance, Scintillometry, Turbulent fluxes, Composite landscape, Evaporative fraction, Sudano-Sahelian climate, AMMA-CATCH, HYBIS},
	pages = {84--98},
}

@article{guyot_combined_2009,
	title = {Combined analysis of energy and water balances to estimate latent heat flux of a sudanian small catchment},
	volume = {375},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/B6V6C-4VF5728-1/2/f98d4acd4616ebc8f12c84aacc03722b},
	doi = {10.1016/j.jhydrol.2008.12.027},
	abstract = {Summary Actual evapotranspiration is one of the major components of both energy and water budgets, but is often difficult to monitor over long period with sufficient accuracy. Within the framework of the "AMMA-CATCH" program, a project dedicated to the study of the West African Monsoon, a large aperture scintillometer has been installed in a small catchment (12 km2), located in the North of Benin, a region exposed to sudanian climate. The present study is an attempt to estimate the latent heat flux over this small but heterogeneous catchment based on scintillation and ground observations. The analysis covers the end of the dry season (lasting from February to April 2006). During this period two isolated rainfall events occurred, giving a unique opportunity to study energy and water budgets simultaneously. The comparison between the average sensible heat flux derived from scintillometer observations and the one obtained with conventional eddy correlation shows a relatively good agreement, where the scattering is mainly explained by differences in footprint associated with both instruments. A relevant hourly residual latent heat flux is then obtained through the energy balance equation, with careful attention brought to the net radiation, and the ground heat fluxes. The residual of the energy budget equation is compared to soil water losses from vadose zone and water table, in order to evaluate whether this estimation is consistent with the water budget of the ground. Daily soil water depletion within the first meter of the surface shows a similar dynamic as the one calculated from the energy balance equation, but exhibits a constant 1 mm/day lag. The excess of actual evapotranspiration is supposed to be explained by water table losses and root extraction by trees. Finally, this study shows how combined energy and water budget analysis can help to better understand water transfers at the watershed scale.},
	number = {1-2},
	journal = {Journal of Hydrology},
	author = {Guyot, Adrien and Cohard, Jean-Martial and Anquetin, Sandrine and Galle, Sylvie and Lloyd, Colin R.},
	month = aug,
	year = {2009},
	keywords = {West Africa, Energy balance closure, Scintillometry, Actual evapotranspiration, Soil water storage, Water balance closure, AMMA-CATCH, HYBIS},
	pages = {227--240},
}

@article{hector_gravity_2013,
	title = {Gravity effect of water storage changes in a weathered hard-rock aquifer in {West} {Africa}: results from joint absolute gravity, hydrological monitoring and geophysical prospection},
	volume = {194},
	url = {http://gji.oxfordjournals.org/content/194/2/737.abstract},
	doi = {10.1093/gji/ggt146},
	abstract = {Advances in groundwater storage monitoring are crucial for water resource management and hydrological processes understanding. The evaluation of water storage changes (WSC) often involve point measurements (observation wells, moisture probes, etc.), which may be inappropriate in heterogeneous media. Over the past few years, there has been an increasing interest in the use of gravimetry for hydrological studies. In the framework of the GHYRAF (Gravity and Hydrology in Africa) project, 3 yr of repeated absolute gravity measurements using a FG5-type gravimeter have been undertaken at Nalohou, a Sudanian site in northern Benin. Hydrological data are collected within the long-term observing system AMMA-Catch. Once corrected for solid earth tides, ocean loading, air pressure effects, polar motion contribution and non-local hydrology, seasonal gravity variations reach up to 11 μGal, equivalent to a WSC of 260-mm thick infinite layer of water. Absolute temporal gravity data are compared to WSC deduced from neutron probe and water-table variations through a direct modelling approach. First, we use neutronic measurements available for the whole vertical profile where WSC occur (the vadose zone and a shallow unconfined aquifer). The RMSD between observed and modelled gravity variations is 1.61 μGal, which falls within the error bars of the absolute gravity data. Second, to acknowledge for the spatial variability of aquifer properties, we use a 2-D model for specific yield (Sy) derived from resistivity mapping and Magnetic Resonance Soundings (MRS). The latter provides a water content (θMRS) known to be higher than the specific yield. Hence, we scaled the 2-D model of θMRS with a single factor (α). WSC are calculated from water-table monitoring in the aquifer layer and neutronic measurements in the vadose layer. The value of α is obtained with a Monte–Carlo sampling approach, minimizing the RMSD between modelled and observed gravity variations. This leads to α = Sy/θMRS = 0.63 ± 0.15, close to what is found in the literature on the basis of pumping tests experiments, with a RMSD value of 0.94 μGal. This hydrogeophysical experiment is a first step towards the use of time-lapse gravity data as an integrative tool to monitor interannual WSC even in complicated subsurface distribution.},
	number = {2},
	journal = {Geophysical Journal International},
	author = {Hector, Basile and Séguis, Luc and Hinderer, Jacques and Descloitres, Marc and Vouillamoz, Jean-Michel and Wubda, Maxime and Boy, Jean-Paul and Luck, Bernard and Le Moigne, Nicolas},
	month = aug,
	year = {2013},
	keywords = {Africa, Hydrology, rainfall, Hydrogeophysics, AMMA-CATCH, Niger, Superconducting gravimeter, HYBIS, benin, variability, magnetic-resonance, system, Time variable gravity, mrs, balance, pressure},
	pages = {737--750},
}

@article{le_lay_model_2008,
	title = {Model representation of the {Sudanian} hydrological processes: {Application} on the {Donga} catchment ({Benin})},
	volume = {363},
	issn = {0022-1694},
	shorttitle = {Model representation of the {Sudanian} hydrological processes},
	url = {http://www.sciencedirect.com/science/article/pii/S0022169408004836},
	doi = {10.1016/j.jhydrol.2008.09.006},
	abstract = {Summary During the AMMA (African Monsoon Multidisciplinary Analysis) program, intensive field experiments were conducted on the Donga catchment (586 km2), which is part of the Ouémé surveyed hydrological watershed (14,400 km2). Based on these studies, a number of general hydrological assumptions were derived to explain the hydrological functioning of catchments located in the Sudanian hydrological area of West Africa. To take advantage of this field-acquired knowledge in the study of the impacts of climate and anthropogenic changes in these catchments, a model (TOPAMMA) was derived based on these hydrological assumptions. Subsurface lateral fluxes were described in the model using the TOPMODEL framework. The recharge of the deep water table was also modelled, taking into account its disconnection from the river network. Simple geomorphologic approaches were used to estimate the time-transfer of both surface and subsurface water fluxes. Finally, to be consistent with the available meteorological data, a simple parameterization of evapotranspiration was added to the model. This paper details this modelisation as well as its corroboration on the Donga catchment. The data collected over the catchment during the 2002-2004 periods was therefore used at different scales, within either a quantitative or qualitative perspective. The results show that the model representation of the water cycle is quite realistic, which allows the AMMA community to have a useful tool available for water balance studies on the Sudanian region. However, further field investigations are necessary to confirm main model assumptions. Finally, the process representation in the model is now improved, especially with regard to the description of spatial land-surface heterogeneities and surface-atmosphere interactions.},
	number = {1-4},
	journal = {Journal of Hydrology},
	author = {Le Lay, M. and Saulnier, G. M. and Galle, S. and Seguis, L. and Métadier, M. and Peugeot, Ch},
	month = dec,
	year = {2008},
	keywords = {West Africa, Hydrological modelling, Multi-criteria evaluation, AMMA-CATCH, benin},
	pages = {32--41},
}

@article{lebel_amma-catch_2009,
	title = {{AMMA}-{CATCH} studies in the {Sahelian} region of {West}-{Africa}: {An} overview},
	volume = {375},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/pii/S0022169409001875},
	doi = {10.1016/j.jhydrol.2009.03.020},
	abstract = {Summary The African Monsoon Multidisciplinary Analysis (AMMA) is an international and interdisciplinary experiment designed to investigate the interactions between atmospheric, oceanic and terrestrial systems and their joint controls on tropical monsoon dynamics in West Africa. This special issue reports results from a group of AMMA studies regrouped in the component “Couplage de l’Atmosphère Tropicale et du Cycle Hydrologique” (CATCH). AMMA-CATCH studies focus on measuring and understanding land surface properties and processes in West Africa, the role of terrestrial systems in altering boundary layer dynamics, and thus the potential that surface hydrology and biology, and human land use practices, may directly or indirectly affect monsoon dynamics and rainfall in the region. AMMA-CATCH studies focus on three intensively instrumented mesoscale sites in Mali, Niger and Benin that sample across the 100–1300 mm/annum rainfall gradient of the Sahel, Sudan and North-Guinean bioclimatic zones. Studies report on: (i) surface–boundary layer interactions that may influence atmospheric convergence and convective processes and thus rainfall type, timing and amount; (ii) vegetation dynamics at seasonal to decadal time-scales that may respond to, and alter, atmospheric processes; (iii) surface–atmosphere fluxes of heat, water and carbon dioxide that directly influence the atmosphere; (iv) soil moisture variability in space and time that provide the proximate control on vegetation activity, evapotranspiration and energy balance; and (v) local and mesoscale modeling of hydrology and land surface–atmosphere exchanges to assess their role in the hydrological, atmospheric and rainfall dynamics of West Africa. The AMMA-CATCH research reported in this issue will be extended in future years as measurements and analysis continue and are concluded within the context of both CATCH and the wider AMMA study. This body of research will contribute to an improved understanding of the functioning of the coupled West African system, and enhance our ability to model and predict rainfall, vegetation and biogeochemical dynamics across time-scales (day, year, decade, and century), and in response to changing climate and land use. Such information is vital for policy makers and managers in planning for future economic development, sustainability and livelihoods of the growing populations of the region.},
	number = {1-2},
	journal = {Journal of Hydrology},
	author = {Lebel, Thierry and Cappelaere, Bernard and Galle, Sylvie and Hanan, Niall and Kergoat, Laurent and Levis, Samuel and Vieux, Baxter and Descroix, Luc and Gosset, Marielle and Mougin, Eric and Peugeot, Christophe and Seguis, Luc},
	month = aug,
	year = {2009},
	keywords = {West Africa, Sahel, Continental scale experiments, Land surface processes, Water resources, AMMA-CATCH, Benin, Niger, Mali, HYBIS, AO},
	pages = {3--13},
}

@article{lloyd_hapex-sahela_1997,
	title = {{HAPEX}-{SahelA} comparison of surface fluxes at the {HAPEX}-{Sahel} fallow bush sites},
	volume = {188-189},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/pii/S0022169496031848},
	doi = {10.1016/S0022-1694(96)03184-8},
	abstract = {The variability between surface flux measurements at the fallow sites of the three HAPEX-Sahel supersites is examined over periods of three or four consecutive days. A roving eddy correlation instrument provided a common base for comparison at each supersite. The inhomogeneity of the surface and the instrumental layout did not provide the conditions to allow the separation of the effects of instrument error from those due to the spatial variability of vegetation cover and soil moisture. Surface fluxes of sensible and latent heat and energy balance terms were intercompared at each supersite over summation timescales of 1 hour and 3 days. It is shown that, generally, HAPEX-Sahel hourly sensible heat flux and latent heat values have confidence limits of 15\% and 20\% respectively. The three-day period energy balance shows the combined sensible and latent heat fluxes to have a confidence limit of 3\%. It is concluded that, due to the averaging effect of longer time periods and larger flux footprints on spatial inhomogeneity, confidence in the surface flux measurements increases with longer summation periods and with neutral atmospheric surface layers which characterise the rainy period of the Intensive Observation Period.},
	language = {en},
	journal = {Journal of Hydrology},
	author = {Lloyd, C. R. and Bessemoulin, P. and Cropley, F. D. and Culf, A. D. and Dolman, A. J. and Elbers, J. and Heusinkveld, B. and Moncrieff, J. B. and Monteny, B. and Verhoef, A.},
	month = feb,
	year = {1997},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {400--425},
}

@article{mamadou_dynamics_2016,
	title = {Dynamics of water vapor and energy exchanges above two contrasting {Sudanian} climate ecosystems in {Northern} {Benin} ({West} {Africa})},
	volume = {121},
	issn = {2169-8996},
	url = {http://dx.doi.org/10.1002/2016JD024749},
	doi = {10.1002/2016jd024749},
	abstract = {Natural ecosystems in sub-Saharan Africa are experiencing intense changes that will probably modify land surface feedbacks and consequently the regional climate. In this study, we have analyzed water vapor (QLE) and sensible heat (QH) fluxes over a woodland (Bellefoungou, BE) and a cultivated area (Nalohou, NA) in the Sudanian climate of Northern Benin, using 2 years (from July 2008 to June 2010) of eddy covariance measurements. The evaporative fraction (EF) response to environmental and surface variables was investigated at seasonal scale. Soil moisture was found to be the main environmental factor controlling energy partitioning. During the wet seasons, EF was rather stable with an average of 0.75 ± 0.07 over the woodland and 0.70 ± 0.025 over the cultivated area. This means that 70–75\% of the available energy was changed into actual evapotranspiration during the investigated wet seasons depending on the vegetation type. The cumulative annual actual evapotranspiration (AET) varied between 730 ± 50 mm yr−1 at the NA site and 1040 ± 70 mm yr−1 at the BE site. With similar weather conditions at the two sites, the BE site showed 30\% higher AET values than the NA site. The sensible heat flux QH at the cultivated site was always higher than that of the woodland site, but observed differences were much less than those of QLE. In a land surface conversion context, these differences are expected to impact both atmospheric dynamics and the hydrological cycle.},
	language = {en},
	number = {19},
	journal = {Journal of Geophysical Research: Atmospheres},
	author = {Mamadou, O. and Galle, S. and Cohard, Jean-Martial and Peugeot, Christophe and Kounouhewa, Basile and Biron, Romain and Hector, Basile and Zannou, Arnaud Bruno},
	month = oct,
	year = {2016},
	keywords = {Sudanian climate, West Africa, 1818 Evapotranspiration, 0438 Diel, seasonal, and annual cycles, eddy covariance, 1843 Land/atmosphere interactions, water balance, 1814 Energy budgets, 3307 Boundary layer processes, actual evapotranspiration, sensible heat flux, AMMA-CATCH, Benin, PHYREV},
	pages = {11,269--11,286},
}

@article{panthou_rainfall_2018,
	title = {Rainfall intensification in tropical semi-arid regions: the {Sahelian} case},
	volume = {13},
	issn = {1748-9326},
	url = {http://stacks.iop.org/1748-9326/13/i=6/a=064013},
	abstract = {An anticipated consequence of ongoing global warming is the intensification of the rainfall regimes meaning longer dry spells and heavier precipitation when it rains, with potentially high hydrological and socio-economic impacts. The semi-arid regions of the intertropical band, such as the Sahel, are facing particularly serious challenges in this respect since their population is strongly vulnerable to extreme climatic events. Detecting long term trends in the Sahelian rainfall regime is thus of great societal importance, while being scientifically challenging because datasets allowing for such detection studies are rare in this region. This study addresses this challenge by making use of a large set of daily rain gauge data covering the Sahel (defined in this study as extending from 20°W–10°E and from 11°N–18°N) since 1950, combined with an unparalleled 5 minute rainfall observations available since 1990 over the AMMA-CATCH Niger observatory. The analysis of the daily data leads to the assertion that a hydro-climatic intensification is actually taking place in the Sahel, with an increasing mean intensity of rainy days associated with a higher frequency of heavy rainfall. This leads in turn to highlight that the return to wetter annual rainfall conditions since the beginning of the 2000s—succeeding the 1970–2000 drought—is by no mean a recovery towards the much smoother regime that prevailed during the 1950s and 1960s. It also provides a vision of the contrasts existing between the West Sahel and the East Sahel, the East Sahel experiencing a stronger increase of extreme rainfall. This regional vision is complemented by a local study at sub-daily timescales carried out thanks to the 5 minute rainfall series of the AMMA-CATCH Niger observatory (12000 km 2 ). The increasing intensity of extreme rainfall is also visible at sub-daily timescales, the annual maximum intensities have increased at an average rate of 2\%–6\% per decade since 1990 for timescales ranging from 5 min to 1 hour. Both visions—regional/long term/daily on the one hand, and local/27/years/sub-daily, on the other—converge to the conclusion that, rather than a rainfall recovery, the Sahel is experiencing a new era of climate extremes that roughly started at the beginning of this century.},
	number = {6},
	journal = {Environmental Research Letters},
	author = {Panthou, G. and Lebel, T. and Vischel, T. and Quantin, G. and Sane, Y. and Ba, A. and Ndiaye, O. and Diongue-Niang, A. and Diopkane, M.},
	year = {2018},
	keywords = {Sahel, AMMA-CATCH, AO, PHYREV},
	pages = {064013},
}

@article{peugeot_hydrologic_2003,
	title = {Hydrologic process simulation of a semiarid, endoreic catchment in {Sahelian} {West} {Niger}. 1. {Model}-aided data analysis and screening},
	volume = {279},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/pii/S0022169403001811},
	doi = {10.1016/S0022-1694(03)00181-1},
	abstract = {The drought in the African Sahel, persisting since 1968, emphasizes the vulnerability of local water resources to climatic variations and land use changes in this semiarid environment. Following the Hapex–Sahel experiment (1992–1994), research aims at understanding and modeling the impact on the hydrological cycle of these changing climatic and environmental conditions over a 1500-km2 area east of Niamey, Niger. The hydrological landscape consists of a myriad of small endoreic catchments feeding temporary or permanent pools from which water percolates to an unconfined aquifer. As the first step in a local-to-regional scale approach to the water resource recharge in the area, a physically based rainfall–runoff model is developed for a typical, 1.9-km2 endoreic system named Wankama, which is monitored continuously since 1992. This first of two companion papers describes the key elements of the hydrological landscape, the experimental setup with which the Wankama catchment and pool are monitored, the r.water.fea distributed hydrological model and its application to the construction of the Wankama catchment model. Because of the difficulties of long-term field experimentation in the region, not all observed events can be considered equally well recorded; in particular, detection of exogenous water inflow occurrences that may alter Wankama runoff estimates is needed. The paper describes the careful, model-aided data analysis performed in order to select the observation set with which the model can most reliably be tuned and operated. In this rainfall–runoff data analysis phase, the model is used prior to any calibration. Model calibration and verification, including output uncertainty, are the subject of the second paper [J. Hydrol. (2003)]. All steps of analysis and modeling were performed on the 1992–1998 data only, before the 1999–2000 data became available, and are tested a posteriori against the latter.},
	language = {en},
	number = {1–4},
	journal = {Journal of Hydrology},
	author = {Peugeot, Christophe and Cappelaere, Bernard and Vieux, Baxter E. and Séguis, Luc and Maia, Ana},
	month = aug,
	year = {2003},
	keywords = {Distributed hydrologic modeling, Hortonian runoff, Sahel, Outliers, Rainfall–runoff, Sample construction, Uncalibrated model, AMMA-CATCH},
	pages = {224--243},
}

@article{ramier_towards_2009,
	title = {Towards an understanding of coupled physical and biological processes in the cultivated {Sahel} - 1. {Energy} and water},
	volume = {375},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/B6V6C-4V4KR2Y-1/2/36964acef1f71694a235c9ff69af83a5},
	doi = {10.1016/j.jhydrol.2008.12.002},
	abstract = {Summary This paper presents an analysis of the coupled cycling of energy and water by semi-arid Sahelian surfaces, based on two years of continuous vertical flux measurements from two homogeneous recording stations in the Wankama catchment, in the West Niger meso-site of the AMMA project. The two stations, sited in a millet field and in a semi-natural fallow savanna plot, sample the two dominant land cover types in this area typical of the cultivated Sahel. The 2-year study period enables an analysis of seasonal variations over two full wet-dry seasons cycles, characterized by two contrasted rain seasons that allow capturing a part of the interannual variability. All components of the surface energy budget (four-component radiation budget, soil heat flux and temperature, eddy fluxes) are measured independently, allowing for a quality check through analysis of the energy balance closure. Water cycle monitoring includes rainfall, evapotranspiration (from vapour eddy flux), and soil moisture at six depths. The main modes of observed variability are described, for the various energy and hydrological variables investigated. Results point to the dominant role of water in the energy cycle variability, be it seasonal, interannual, or between land cover types. Rainfall is responsible for nearly as much seasonal variations of most energy-related variables as solar forcing. Depending on water availability and plant requirements, evapotranspiration pre-empts the energy available from surface forcing radiation, over the other dependent processes (sensible and ground heat, outgoing long wave radiation). In the water budget, pre-emption by evapotranspiration leads to very large variability in soil moisture and in deep percolation, seasonally, interannually, and between vegetation types. The wetter 2006 season produced more evapotranspiration than 2005 from the fallow but not from the millet site, reflecting differences in plant development. Rain-season evapotranspiration is nearly always lower at the millet site. Higher soil moisture at this site suggests that this difference arises from lower vegetation requirements rather than from lower infiltration/higher runoff. This difference is partly compensated for during the next dry season. Effects of water and vegetation on the energy budget appear to occur more through latent heat than through albedo. A large part of albedo variability comes from soil wetting and drying. Prior to the onset of monsoon rain, the change in air mass temperature and wind produces, through modulation of sensible heat, a marked chilling effect on the components of the surface energy budget.},
	number = {1-2},
	journal = {Journal of Hydrology},
	author = {Ramier, David and Boulain, Nicolas and Cappelaere, Bernard and Timouk, Franck and Rabanit, Manon and Lloyd, Colin R. and Boubkraoui, Stéphane and Métayer, Frédéric and Descroix, Luc and Wawrzyniak, Vincent},
	month = aug,
	year = {2009},
	keywords = {Eddy covariance, Evaporation, Fallow savanna, Millet, Hydrologic cycle, Semi-arid, Surface energy budget, Runoff, climate, AMMA-CATCH, HYBIS, west-africa, hapex-sahel, variability, land-surface, balance closure, millet, savanna, surface-properties},
	pages = {204--216},
}

@article{redelsperger_surface_2009,
	title = {Surface processes and water cycle in {West} {Africa}, studied from the {AMMA}-{CATCH} observing system},
	volume = {375},
	issn = {0022-1694},
	url = {http://apps.isiknowledge.com/full_record.do?product=WOS&search_mode=GeneralSearch&qid=1&SID=Y1a3kLPaIOHdJpjgG2K&page=1&doc=1},
	doi = {10.1016/j.jhydrol.2009.08.017},
	number = {1-2},
	journal = {Journal of Hydrology},
	author = {Redelsperger, J.-L. and Lebel, T.},
	month = aug,
	year = {2009},
	keywords = {AMMA-CATCH},
	pages = {1--2},
}

@article{redelsperger_african_2006,
	title = {African {Monsoon} {Multidisciplinary} {Analysis}. {An} international research project and field campaign},
	volume = {87},
	url = {http://dx.doi.org/10.1175%2FBAMS-87-12-1739},
	doi = {10.1175/BAMS-87-12-1739},
	abstract = {African Monsoon Multidisciplinary Analysis (AMMA) is an international project to improve our knowledge and understanding of the West African monsoon (WAM) and its variability with an emphasis on daily-to-interannual time scales. AMMA is motivated by an interest in fundamental scientific issues and by the societal need for improved prediction of the WAM and its impacts on West African nations. Recognizing the societal need to develop strategies that reduce the socioeconomic impacts of the variability of the WAM, AMMA will facilitate the multidisciplinary research required to provide improved predictions of the WAM and its impacts. This will be achieved and coordinated through the following five international working groups: i) West African monsoon and global climate, ii) water cycle, iii) surface\&\#8211;atmosphere feedbacks, iv) prediction of climate impacts, and v) high-impact weather prediction and predictability.AMMA promotes the international coordination of ongoing activities, basic research, and a multiyear field campaign over West Africa and the tropical Atlantic. AMMA is developing close partnerships between those involved in basic research of the WAM, operational forecasting, and decision making, and is establishing blended training and education activities for Africans.},
	number = {12},
	journal = {Bulletin of the American Meteorological Society},
	author = {Redelsperger, Jean-Luc and Thorncroft, Chris D. and Diedhiou, Arona and Lebel, Thierry and Parker, Douglas J. and Polcher, Jan},
	year = {2006},
	keywords = {AMMA-CATCH, AO},
	pages = {1739--1746},
}

@article{seguis_contrasted_2011,
	title = {Contrasted land-surface processes along the {West} {African} rainfall gradient},
	volume = {12},
	issn = {1530-261X},
	url = {http://dx.doi.org/10.1002/asl.327},
	doi = {10.1002/asl.327},
	abstract = {Abstract We review the main results of land-surface studies obtained in the three sites of the long-term observing system AMMA-CATCH. Runoff in the Sahel enhances the variability of energy partitioning between non-infiltrative areas where sensible heat is dominant and infiltrative areas where soil water availability increases the latent flux. In terms of water resources, an increase in runoff over the past 50 years, already reported for the exoreic Sahel, was revealed in the endoreic Sahel. In the Sudanian domain, the subsurface origin of streamflow could explain its decrease over the same period. Copyright © 2011 Royal Meteorological Society},
	number = {1},
	journal = {Atmospheric Science Letters},
	author = {Séguis, L. and Boulain, N. and Cappelaere, B. and Cohard, J. M. and Favreau, G. and Galle, S. and Guyot, A. and Hiernaux, P. and Mougin, É and Peugeot, C. and Ramier, D. and Seghieri, J. and Timouk, F. and Demarez, V. and Demarty, J. and Descroix, L. and Descloitres, M. and Grippa, M. and Guichard, F. and Kamagaté, B. and Kergoat, L. and Lebel, T. and Le Dantec, V. and Le Lay, M. and Massuel, S. and Trichon, V.},
	year = {2011},
	keywords = {Sudanian climate, Sahel, energy fluxes, groundwater, runoff, water resources, AMMA-CATCH, HYBIS},
	pages = {31--37},
}

@article{seguis_origins_2011,
	title = {Origins of streamflow in a crystalline basement catchment in a sub-humid {Sudanian} zone: {The} {Donga} basin ({Benin}, {West} {Africa}): {Inter}-annual variability of water budget},
	volume = {402},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/pii/S0022169411000898},
	doi = {10.1016/j.jhydrol.2011.01.054},
	abstract = {Summary During the last quarter of the 20th century, West Africa underwent a particularly intense and generalized drought. During this period, the biggest drops in streamflow were observed in the Sudanian zone rather than in the Sahelian zone, but the reasons are still poorly understood. In 2000, a meso-scale hydrological observatory was set up in the sub-humid Sudanian zone of the Upper Ouémé Valley (Benin). Three embedded catchments of 12–586\&\#xa0;km2 located on a crystalline bedrock were intensively instrumented to document the different terms of the water budget and to identify the main streamflow generating processes and base-flow mechanisms at different scales. Geophysical, hydrological and geochemical data were collected throughout the catchments from 2002 to 2006. Crossing these data helped define their hydrological functioning. The region has seasonal streamflow, and the permanent groundwater in the weathered mantle does not drain to rivers, instead, seasonal perched groundwaters are the major contributor to annual streamflow. The perched groundwaters are mainly located in seasonally waterlogged sandy layers in the headwater bottom-lands called bas-fonds in French-speaking West Africa of 1st order streams. During the period 2003–2006, regolith groundwater recharge ranged between 10\% and 15\% of the annual rainfall depth. Depletion of permanent groundwater during the dry season is probably explained by local evapotranspiration which was seen not to be limited to gallery forests. During the 4-year study period, a reduction of 20\% in annual rainfall led to a 50\% reduction in streamflow. This reduction was observed in the two components of the flow: direct runoff and drainage of perched groundwater. Thanks to the comprehensive dataset obtained, the results obtained for the Donga experimental catchment are now being extrapolated to the whole upper Ouémé valley, which can be considered as representative of sub-humid Sudanian rivers flowing on a crystalline basement, for example, the upper courses of several major West African rivers (Senegal, Niger, Bani, and Volta).},
	number = {1–2},
	journal = {Journal of Hydrology},
	author = {Séguis, L. and Kamagaté, B. and Favreau, G. and Descloitres, M. and Seidel, J. L. and Galle, S. and Peugeot, C. and Gosset, M. and Le Barbé, L. and Malinur, F. and Van Exter, S. and Arjounin, M. and Boubkraoui, S. and Wubda, M.},
	year = {2011},
	keywords = {Sudanian climate, West Africa, Basement catchment, Perched aquifer, Streamflow decomposition, Water isotopes, AMMA-CATCH, HYBIS, benin},
	pages = {1--13},
}

@article{tanguy_new_2012,
	title = {A new parameterisation scheme of ground heat flux for land surface flux retrieval from remote sensing information},
	volume = {454–455},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/pii/S0022169412004738},
	doi = {10.1016/j.jhydrol.2012.06.002},
	abstract = {The objective of the study was to assess the performance of a new parameterisation scheme of ground heat flux (G) for retrieving surface fluxes from remote sensing data (MODIS-Terra). Formulae that are based on empirical relationships relating G to net radiation, R-n (G = alpha R-n, alpha being a function of a vegetation index, VI) are currently used, but presented drawbacks, especially in bare or sparse vegetation areas because of the poor adequacy of VI-based relationships to account for changes in soil moisture. In this study, we proposed to link a to the evaporative fraction, EF. In a first step, using a non-dimensional form of the surface energy balance, we demonstrated that a is functionally related to EF and to the ratio gamma = G/H (H = sensible heat flux). In a second step, we proposed an EF-based parameterisation of alpha, using ground fluxes data sets collected throughout the years 2005, 2006 and 2007 at four flux-tower sites in West African countries (Mali, Benin, Niger) that differ in surface conditions and Monsoon influence. The analysis indicated that the average site-specific values of alpha and EF were well described by a linear relationship of the type alpha = a EF + b, with a = -0.22 and b = 0.23. In a third stage, we investigated whether ET-retrieval from remote sensing information (MODIS-Terra) using the new parameterisation of alpha perform better than the classical formulation through VI-based relationships. We found that the retrieved values of H using the new parameterisation supplied the best agreement with the observed ground data and significant improvement with respect to estimates from alpha-VI relationships. Advantages and limitations of the proposed parameterisation scheme were discussed. (C) 2012 Elsevier B.V. All rights reserved.},
	language = {English},
	number = {0},
	journal = {Journal of Hydrology},
	author = {Tanguy, M. and Baille, A. and González-Real, M. M. and Lloyd, C. and Cappelaere, B. and Kergoat, L. and Cohard, J. M.},
	month = aug,
	year = {2012},
	keywords = {Ground heat flux, Sensible heat flux, Remote sensing, remote sensing, Evaporative fraction, sensible heat flux, Vegetation index, AMMA-CATCH, HYBIS, AO, satellite data, evaporative fraction, clear-sky days, energy balance algorithm, net-radiation ratio, regional evapotranspiration, soil-water content, southern great-plains, thermal inertia, triangle method, vegetation index, vegetation indexes},
	pages = {113--122},
}

@article{timouk_response_2009,
	title = {Response of surface energy balance to water regime and vegetation development in a {Sahelian} landscape},
	volume = {375},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/B6V6C-4W6Y5S4-1/2/a86fdbfe6d61a2530c74770b5619fcf0},
	doi = {10.1016/j.jhydrol.2009.04.022},
	abstract = {The West African monsoon interacts strongly with the land surface, yet knowledge of these interactions is severely limited by the lack of observations of surface energy fluxes. Within the framework of the AMMA project, three eddy covariance flux stations were installed to sample the three main surface types near Hombori (Mali) in the central Sahel at 15.3 degrees N, and a fourth station was installed near Bamba in the northern Sahel at 17.1 degrees N to sample semi-desert conditions. Observed land types near Hombori comprised a grassland growing on sandy soil (near the village of Agoufou), a flooded forest in a clay-soil depression (Kelma), and a bare rocky soil (Eguerit). The energy balance closure at the grassland site was satisfactory, but less so at the flooded forest site. Surface water heat storage during the flood and advection probably were responsible for most of the imbalance. The daily sensible heat flux (H) was fairly constant throughout the year at Bamba and Eguerit, with only a slight increase during the monsoon season corresponding to increased net radiation. By contrast, the seasonal cycle of the grassland site was marked, with H decreasing during the monsoon season from 70 W m(-2) in May to 20 W m(-2) in August. The flooded woodland exhibited the strongest contrast between the dry and wet seasons, with daily sensible heat flux close to zero during the flood. During the peak monsoon season, the two vegetated sites had the highest net radiation and the lowest sensible heat flux, as a consequence of the strong evapotranspiration rates caused by both high soil moisture availability and high leaf area index. Lateral fluxes of water were found to be strong drivers of inter-site sensible and latent heat fluxes variability, with water leaving bare rocky soils as surface runoff and ending in the clay depressions (e.g., Kelma), whereas the sandy soils were locally endorheic, with most of the rainfall being rapidly returned to the atmosphere. An attempt was made to scale the sensible heat flux up to the scale of the AMMA northern super-site (60 km x 60 km), following a simple scaling scheme, which accounted for the contrasting surface types and water regimes. The super-site average sensible heat flux proved to be close to the grassland sensible heat flux, in part because grassland occupies 55\% of the area. A strong spatial variability was caused by the difference in water regime and vegetation type, at a scale large enough to potentially influence the atmospheric properties such as the boundary layer. (C) 2009 Elsevier B.V. All rights reserved.},
	number = {1-2},
	journal = {Journal of Hydrology},
	author = {Timouk, F. and Kergoat, L. and Mougin, E. and Lloyd, C. R. and Ceschia, E. and Cohard, J. M. and Rosnay, P. de and Hiernaux, P. and Demarez, V. and Taylor, C. M.},
	month = aug,
	year = {2009},
	keywords = {Sensible heat flux, Net radiation, AMMA, Sahel, Latent heat flux, flux, sensible heat flux, heat, rainfall, Grassland, climate, AMMA-CATCH, Mali, HYBIS, variability, feedback, land-surface, latent heat flux, net radiation, part i, Temperature},
	pages = {178--189},
}

@article{vischel_assessing_2007,
	title = {Assessing the water balance in the {Sahel}: {Impact} of small scale rainfall variability on runoff. {Part} 2: {Idealized} modeling of runoff sensitivity},
	volume = {333},
	issn = {0022-1694},
	shorttitle = {Assessing the water balance in the {Sahel}},
	url = {http://www.sciencedirect.com/science/article/pii/S002216940600477X},
	doi = {10.1016/j.jhydrol.2006.09.007},
	abstract = {As in many other semi-arid regions in the world, the Sahelian hydrological environment is characterized by a mosaic of small endoreic catchments with dry soil surface conditions producing mostly Hortonian runoff. Using an SCS-type event based rainfall–runoff model, an idealized modeling experiment of a Sahelian environment is set up to study the sensitivity of runoff to small scale rainfall variability. A set of 548 observed rain events is used to force the hydrological model to study the sensitivity of runoff to the time and space variability of rainfall input. The rainfall time variability sensitivity analysis shows that preserving the event rain depth without representing the main variabilities of the hyetograph intensities can translate into a runoff error of 65\% in the worst case. On a virtual mosaic of 1-km2 catchments covering 10,000 km2, the simulated runoff shows a high sensitivity to a decrease of the spatial resolution of event rain fields from 1 × 1 km2 to 100 × 100 km2. For the catchments characterized by low runoff coefficients, which are the most sensitive to rainfall variability, at the coarsest spatial resolution of 100 × 100 km2, the global runoff computed from the 548 events is underestimated by 50\% with respect to the runoff simulated from the 1 × 1 km2 resolution rain fields. The threshold resolution of 20 km was identified as a characteristic spatial scale, over which the performance of the model rapidly decreases. Looking at the influence of the number of available rain gauges, the effect of spatial aggregation depends on the density of the rain gauge network with lower effect for sparser networks.},
	number = {2-4},
	journal = {Journal of Hydrology},
	author = {Vischel, Théo and Lebel, Thierry},
	year = {2007},
	keywords = {Rainfall space–time resolution, Runoff, SCS-type hydrologic model, Semi-arid endoreic environment, AMMA-CATCH, niger},
	pages = {340--355},
}

@article{vischel_generation_2011,
	title = {Generation of {High}-{Resolution} {Rain} {Fields} in {West} {Africa}: {Evaluation} of {Dynamic} {Interpolation} {Methods}},
	volume = {12},
	issn = {1525-755X},
	url = {http://dx.doi.org/10.1175/JHM-D-10-05015.1},
	doi = {10.1175/jhm-d-10-05015.1},
	abstract = {AbstractHigh-resolution rain fields are a prerequisite to many hydrometeorological studies. For some applications, the required resolution may be as fine as 1 km in space and 5 min in time. At these scales, rainfall is strongly intermittent, variable in space, and correlated in time because of the propagation of the rainy systems. This paper compares two interpolation approaches to generate high-resolution rain fields from rain gauge measurements: (i) a classic interpolation technique that consists in interpolating independently the rain intensities at each time step (Eulerian kriging) and (ii) a simple dynamic interpolation technique that incorporates the propagation of the rainy systems (Lagrangian kriging). For this latter approach, three propagation models are tested. The different interpolation techniques are evaluated over three climatically contrasted areas in West Africa where a multiyear 5-min rainfall dataset has been collected during the African Monsoon Multidisciplinary Analyses (AMMA) campaigns. The dynamic interpolation technique is shown to perform better than the classic approach for a majority of the rainy events. The performances of the three propagation models differ from one another, depending on the evaluation criteria used. One of them provides a satisfactory time of arrival of rainfall but slightly smooths the rain intensities. The two others reproduce well the rain intensities, but the time of arrival of the rain is sometimes delayed. The choice of an appropriate propagation algorithm will thus depend on the operational objectives underlying the rain field generation.},
	number = {6},
	urldate = {2014-12-14},
	journal = {Journal of Hydrometeorology},
	author = {Vischel, T. and Quantin, G. and Lebel, T. and Viarre, J. and Gosset, M. and Cazenave, F. and Panthou, G.},
	month = dec,
	year = {2011},
	keywords = {Sahel, Runoff, AMMA-CATCH, scale, HYBIS, variability, Radar, water-balance, impact, gauge, geostatistical interpolation, tropical rainfall},
	pages = {1465--1482},
}

@article{wendling_drought-induced_2019,
	title = {Drought-induced regime shift and resilience of a {Sahelian} ecohydrosystem},
	volume = {14},
	issn = {1748-9326},
	url = {https://iopscience.iop.org/article/10.1088/1748-9326/ab3dde},
	doi = {10.1088/1748-9326/ab3dde},
	abstract = {The Sahel (a semi-arid fringe south of the Sahara) experienced a long and prolonged drought from the 1970s to the mid-1990s, with a few extremely severe episodes that strongly affected ecosystems and societies. Long-term observations showed that surface runoff increased during this period, despite the rainfall deficit. This paradox stems from the soil degradation that was induced by various factors, either directly linked to the drought (impact on vegetation cover), or, in places, to human practices (land clearing and cropping). Surface runoff is still increasing throughout the region, suggesting that Sahelian ecohydrosystems may have shifted to a new hydrological regime. In order to explore this issue, we have developed a simple system dynamics model incorporating vegetation–hydrology interactions and representing in a lumped way the first order processes occurring at the hillslope scale and the annual timestep. Long term observations on a pilot site in northern Mali were used to constrain the model and define an ensemble of plausible simulations. The model successfully reproduced the vegetation collapse and the runoff increase observed over the last 60 years. Our results confirmed that the system presents two alternative states and that during the drought it shifted from a high-vegetation/low-runoff regime to the alternative low-vegetation/high-runoff one, where it has remained trapped until now. We showed that the mean annual rainfall deficit was sufficient to explain the shift. According to the model, vegetation recovery and runoff reduction are possible in this system, but the conditions in which they could occur remain uncertain as the model was only constrained by observations over the collapse trajectory. The study shows that the system is also sensitive to the interannual and decadal variability of rainfall, and that larger variability leads to higher runoff. Both mean rainfall and rainfall variability may increase in central Sahel under climate change, leading to antagonist effects on the system, which makes its resilience uncertain.},
	number = {10},
	journal = {Environmental Research Letters},
	author = {Wendling, Valentin and Peugeot, Christophe and Mayor, Angeles G. and Hiernaux, Pierre and Mougin, Eric and Grippa, Manuela and Kergoat, Laurent and Walcker, Romain and Galle, Sylvie and Lebel, Thierry},
	month = oct,
	year = {2019},
	keywords = {AMMA-CATCH, LMI REZOC, IGE, sahel, tipping point},
	pages = {105005},
}

@article{hinderer_study_2020,
	title = {A study of the monsoonal hydrology contribution using a 8-yr record (2010–2018) from superconducting gravimeter {OSG}-060 at {Djougou} ({Benin}, {West} {Africa})},
	volume = {221},
	issn = {0956-540X, 1365-246X},
	url = {https://doi.org/10.1093/gji/ggaa027},
	doi = {10.1093/gji/ggaa027},
	abstract = {We analyse a nearly 8-yr record (2010–2018) of the superconducting gravimeter OSG-060 located at Djougou (Benin, West Africa). After tidal analysis removing all solid Earth and ocean loading tidal contributions and correcting for the long-term instrumental drift and atmospheric loading, we obtain a gravity residual signal which is essentially a hydrological signal due to the monsoon. This signal is first compared to several global hydrology models (ERA, GLDAS and MERRA). Our superconducting gravimeter residual signal is also superimposed onto episodic absolute gravity measurements and to space gravimetry GRACE data. A further comparison is done using local hydrological data like soil moisture in the very superficial layer (0–1.2 m), water table depth and rainfall. The temporal evolution of the correlation coefficient between the gravity observation and both the soil moisture and the water table is well explained by the direct infiltration process of rain water together with the lateral transfer discharging the water table.Finally, we compute the water storage changes (WSC) using a simulation based on the physically based Parflow-CLM numerical model of the catchment, which solves the water and energy budget from the impermeable bedrock to the top of the canopy layer using the 3-D Richards equation for the water transfers in the ground, the kinematic wave equation for the surface runoff and a land surface model (CLM) for the energy budget and evapotranspiration calculation.This model forced by rain is in agreement with evapotranspiration and stream flow data and leads to simulated water storage changes that nicely fit to the observed gravity signal. This study points out the important role played by surface gravity changes in terms of a reliable proxy for water storage changes occurring in small catchments.},
	language = {en},
	number = {1},
	urldate = {2020-03-20},
	journal = {Geophysical Journal International},
	author = {Hinderer, J and Hector, B and Riccardi, U and Rosat, S and Boy, J-P and Calvo, M and Littel, F and Bernard, J-D},
	month = apr,
	year = {2020},
	keywords = {AMMA-CATCH, ext1, LMI REZOC},
	pages = {431--439},
}

@article{foucras_estimating_2020,
	title = {Estimating 500-m {Resolution} {Soil} {Moisture} {Using} {Sentinel}-1 and {Optical} {Data} {Synergy}},
	volume = {12},
	issn = {2073-4441},
	url = {https://www.mdpi.com/2073-4441/12/3/866},
	doi = {10.3390/w12030866},
	abstract = {The aim of this study is to estimate surface soil moisture at a spatial resolution of 500 m and a temporal resolution of at least 6 days, by combining remote sensing data from Sentinel-1 and optical data from Sentinel-2 and MODIS (Moderate-Resolution Imaging Spectroradiometer). The proposed methodology is based on the change detection technique, applied to a series of measurements over a three-year period (2015 to 2018). The algorithm described here as “Soil Moisture Estimations from the Synergy of Sentinel-1 and optical sensors (SMES)” proposes different options, allowing information from vegetation densities and seasonal conditions to be taken into account. The output from this algorithm is a moisture index ranging between 0 and 1, with 0 corresponding to the driest soils and 1 to the wettest soils. This methodology has been tested at different test sites (South of France, Central Tunisia, Western Benin and Southwestern Niger), characterized by a wide range of different climatic conditions. The resulting surface soil moisture estimations are compared with in situ measurements and already existing satellite-derived soil moisture ASCAT (Advanced SCATterometer) products. They are found to be well correlated, for the African regions in particular (RMSE below 6 vol.\%). This outcome indicates that the proposed algorithm can be used with confidence to estimate the surface soil moisture of a wide range of climatically different sites.},
	language = {en},
	number = {3},
	urldate = {2020-03-20},
	journal = {Water},
	author = {Foucras, Myriam and Zribi, Mehrez and Albergel, Clément and Baghdadi, Nicolas and Calvet, Jean-Christophe and Pellarin, Thierry},
	month = mar,
	year = {2020},
	keywords = {AMMA-CATCH, ext1},
	pages = {866},
}

@article{pellarin_precipitation_2020,
	title = {The {Precipitation} {Inferred} from {Soil} {Moisture} ({PrISM}) {Near} {Real}-{Time} {Rainfall} {Product}: {Evaluation} and {Comparison}},
	volume = {12},
	issn = {2072-4292},
	shorttitle = {The {Precipitation} {Inferred} from {Soil} {Moisture} ({PrISM}) {Near} {Real}-{Time} {Rainfall} {Product}},
	url = {https://www.mdpi.com/2072-4292/12/3/481},
	doi = {10.3390/rs12030481},
	abstract = {Near real-time precipitation is essential to many applications. In Africa, the lack of dense rain-gauge networks and ground weather radars makes the use of satellite precipitation products unavoidable. Despite major progresses in estimating precipitation rate from remote sensing measurements over the past decades, satellite precipitation products still suffer from quantitative uncertainties and biases compared to ground data. Consequently, almost all precipitation products are provided in two modes: a real-time mode (also called early-run or raw product) and a corrected mode (also called final-run, adjusted or post-processed product) in which ground precipitation measurements are integrated in algorithms to correct for bias, generally at a monthly timescale. This paper describes a new methodology to provide a near-real-time precipitation product based on satellite precipitation and soil moisture measurements. Recent studies have shown that soil moisture intrinsically contains information on past precipitation and can be used to correct precipitation uncertainties. The PrISM (Precipitation inferred from Soil Moisture) methodology is presented and its performance is assessed for five in situ rainfall measurement networks located in Africa in semi-arid to wet areas: Niger, Benin, Burkina Faso, Central Africa, and East Africa. Results show that the use of SMOS (Soil Moisture and Ocean Salinity) satellite soil moisture measurements in the PrISM algorithm most often improves the real-time satellite precipitation products, and provides results comparable to existing adjusted products, such as TRMM (Tropical Rainfall Measuring Mission), GPCC (Global Precipitation Climatology Centre) and IMERG (Integrated Multi-satellitE Retrievals for GPM), which are available a few weeks or months after their detection.},
	language = {en},
	number = {3},
	urldate = {2020-03-20},
	journal = {Remote Sensing},
	author = {Pellarin, Thierry and Román-Cascón, Carlos and Baron, Christian and Bindlish, Rajat and Brocca, Luca and Camberlin, Pierre and Fernández-Prieto, Diego and Kerr, Yann H. and Massari, Christian and Panthou, Geremy and Perrimond, Benoit and Philippon, Nathalie and Quantin, Guillaume},
	month = feb,
	year = {2020},
	keywords = {West Africa, AMMA-CATCH, IGE},
	pages = {481},
}

@article{chagnaud_boundary_2020,
	title = {A {Boundary} {Forcing} {Sensitivity} {Analysis} of the {West} {African} {Monsoon} {Simulated} by the {Modèle} {Atmosphérique} {Régional}},
	volume = {11},
	issn = {2073-4433},
	url = {https://www.mdpi.com/2073-4433/11/2/191},
	doi = {10.3390/atmos11020191},
	abstract = {The rainfall regime of West Africa is highly variable over a large range of space and time scales. With rainfall agriculture being predominent in the region, the local population is extremely vulnerable to intraseasonal dry spells and multi-year droughts as well as to intense rainfall over small time steps. Were this variability to increase, it might render the area close from becoming unhabitable. Anticipating any change is thus crucial from both a societal and a scientific perspective. Despite continuous efforts in Global Climate Model (GCM) development, there is still no agreement on the sign of the future rainfall regime change in the region. Regional Climate Models (RCMs) are used for more accurate projections of future changes as well as end-user-oriented impact studies. In this study, the sensitivity of the Modèle Atmosphérique Régional (MAR) to homogeneous perturbations in boundary forcing air temperature and/or SST is assessed with the aim to better understand (i) the thermodynamical imprint of the recent rainfall regime changes and (ii) the impact of errors in driving data on the West African rainfall regime simulated by an RCM. After an evaluation step where the model is proved to satisfactorily simulate the West African Monsoon (WAM), sensitivity experiments display contrasted, sizable and robust responses of the simulated rainfall regime. The rainfall responses to the boundary forcing perturbations compare in magnitude with the intrinsic model bias, giving support for such an analysis. A physical interpretation of the rainfall anomalies provides confidence in the model response consistency and shows the potential of such an experimental protocol for future climate change downscalling over this region.},
	language = {en},
	number = {2},
	urldate = {2020-03-23},
	journal = {Atmosphere},
	author = {Chagnaud, Guillaume and Gallée, Hubert and Lebel, Thierry and Panthou, Gérémy and Vischel, Théo},
	month = feb,
	year = {2020},
	keywords = {West Africa, AMMA-CATCH, LMI REZOC, IGE},
	pages = {191},
}

@article{bodian_recent_2020,
	title = {Recent {Trend} in {Hydroclimatic} {Conditions} in the {Senegal} {River} {Basin}},
	volume = {12},
	issn = {2073-4441},
	url = {https://www.mdpi.com/2073-4441/12/2/436},
	doi = {10.3390/w12020436},
	abstract = {Analyzing trends of annual rainfall and assessing the impacts of these trends on the hydrological regime are crucial in the context of climate change and increasing water use. This research investigates the recent trend of hydroclimatic variables in the Senegal River basin based on 36 rain gauge stations and three hydrometric stations not influenced by hydraulic structures. The Man Kendall and Pettitt’s tests were applied for the annual rainfall time series from 1940 to 2013 to detect the shift and the general trend of the annual rainfall. In addition, trends of average annual flow rate (AAFR), maximum daily flow (MADF), and low flow rate (LFR) were evaluated before and after annual rainfall shift. The results show that the first shift is situated on average at 1969 whereas the second one is at 1994. While the first shift is very consistent between stations (between 1966 and 1972), there is a significant dispersion of the second change-point between 1984 and 2002. After the second shift (1994), an increase of annual rainfall is noticed compared to the previous period (1969–1994) which indicates a not significant, partial rainfall recovery at the basin level. The relative changes of hydrologic variables differ based on the variables and the sub-basin. Relative changes before and after first change-point are significantly negative for all variables. The highest relative changes are observed for the AAFR. Considering the periods before and second shifts, the relative changes are mainly significantly positive except for the LFR.},
	language = {en},
	number = {2},
	urldate = {2020-03-23},
	journal = {Water},
	author = {Bodian, Ansoumana and Diop, Lamine and Panthou, Geremy and Dacosta, Honoré and Deme, Abdoulaye and Dezetter, Alain and Ndiaye, Pape Malick and Diouf, Ibrahima and Vischel, Théo},
	month = feb,
	year = {2020},
	keywords = {AMMA-CATCH, ext1, IGE, senegal},
	pages = {436},
}

@article{allies_evapotranspiration_2020,
	title = {Evapotranspiration {Estimation} in the {Sahel} {Using} a {New} {Ensemble}-{Contextual} {Method}},
	volume = {12},
	issn = {2072-4292},
	url = {https://www.mdpi.com/2072-4292/12/3/380},
	doi = {10.3390/rs12030380},
	abstract = {In many tropical areas, evapotranspiration is the most important but least known component of the water cycle. An innovative method, named E3S (for EVASPA S-SEBI Sahel), was developed to provide spatially-distributed estimates of daily actual evapotranspiration (ETd) from remote sensing data in the Sahel. This new method combines the strengths of a contextual approach that is used to estimate the evaporative fraction (EF) from surface temperature vs. albedo scatterograms and of an ensemble approach that derives ETd estimates from a weighted average of evapotranspiration estimated from several EF methods. In this work, the two combined approaches were derived from the simplified surface energy balance index (S-SEBI) model and the EVapotranspiration Assessment from SPAce (EVASPA) tool. Main innovative aspects concern (i) ensemble predictions of ETd through the implementation of a dynamic weighting scheme of several evapotranspiration estimations, (ii) epistemic uncertainty of the estimation of ETd from the analysis of the variability of evapotranspiration estimates, and (iii) a new cloud filtering method that significantly improves the detection of cloud edges that negatively affect EF determination. E3S was applied to MODIS/TERRA and AQUA datasets acquired during the 2005–2008 period over the mesoscale AMMA-CATCH (Analyse Multidisciplinaire de la Mousson Africaine—Couplage de l’Atmosphère Tropicale et du Cycle Hydrologique) observatory in South-West Niger. E3S estimates of instantaneous and daily available energy, evaporative fraction, and evapotranspiration were evaluated at a local scale based on two field-monitored plots representing the two main ecosystem types in the area—a millet crop and a fallow savannah bush. In addition to these ground-based observations, the local scale evaluation was performed against continuous simulations by a locally-calibrated soil-vegetation-atmosphere transfer model for the two plots. The RMSE (root mean square error) from this comparison for E3S’s ETd estimates from combined AQUA/TERRA sources was 0.5 mm·day−1, and the determination coefficient was 0.90. E3S significantly improved representation of the evapotranspiration seasonality, compared with a classical implementation of S-SEBI or with the original EVASPA’s non-weighted ensemble scheme. At the mesoscale, ETd estimates were obtained with an average epistemic uncertainty of 0.4 mm·day−1. Comparisons with the reference 0.25°-resolution GLEAM (global land evaporation Amsterdam model) product showed good agreement. These results suggested that E3S could be used to produce reliable continuous regional estimations at a kilometric resolution, consistent with land and water management requirements in the Sahel. Moreover, all these innovations could be easily transposed to other contextual approaches.},
	language = {en},
	number = {3},
	urldate = {2020-04-14},
	journal = {Remote Sensing},
	author = {Allies, Aubin and Demarty, Jérôme and Olioso, Albert and Bouzou Moussa, Ibrahim and Issoufou, Hassane Bil-Assanou and Velluet, Cécile and Bahir, Malik and Maïnassara, Ibrahim and Oï, Monique and Chazarin, Jean-Philippe and Cappelaere, Bernard},
	month = jan,
	year = {2020},
	keywords = {AMMA-CATCH},
	pages = {380},
}

@article{braud_building_2020,
	title = {Building the information system of the {French} {Critical} {Zone} {Observatories} network: {Theia}/{OZCAR}-{IS}},
	volume = {Special Issue: Hydrological data: opportunities and barriers},
	issn = {0262-6667, 2150-3435},
	shorttitle = {Building the information system of the {French} {Critical} {Zone} {Observatories} network},
	url = {https://www.tandfonline.com/doi/full/10.1080/02626667.2020.1764568},
	doi = {10.1080/02626667.2020.1764568},
	language = {en},
	urldate = {2020-05-06},
	journal = {Hydrological Sciences Journal},
	author = {Braud, Isabelle and Chaffard, Véronique and Coussot, Charly and Galle, Sylvie and Juen, Patrick and Alexandre, Hugues and Baillion, Philippe and Battais, Annick and Boudevillain, Brice and Branger, Flora and Brissebrat, Guillaume and Cailletaud, Rémi and Cochonneau, Gérard and Decoupes, Rémy and Desconnets, Jean-Christophe and Dubreuil, Arnaud and Fabre, Juliette and Gabillard, Santiago and Gérard, Marie-Françoise and Grellet, Sylvain and Herrmann, Agnès and Laarman, Olivier and Lajeunesse, Eric and Le Hénaff, Geneviève and Lobry, Olivier and Mauclerc, Antony and Paroissien, Jean-Baptiste and Pierret, Marie-Claire and Silvera, Norbert and Squividant, Hervé},
	month = may,
	year = {2020},
	keywords = {AMMA-CATCH, ext1, LMI REZOC, IGE, OZCAR, theia},
	pages = {02626667.2020.1764568},
}

@article{legchenko_feasibility_2020,
	title = {Feasibility study of a surface-borehole {NMR} method},
	volume = {177},
	issn = {0926-9851},
	url = {https://www.sciencedirect.com/science/article/pii/S0926985119306147},
	doi = {10.1016/j.jappgeo.2020.104039},
	abstract = {We present results of a feasibility study of a borehole induction-coil sensor for surface-borehole NMR (SBNMR) investigations. This sensor of 7 cm diameter and 180 cm length is connected to a standard MRS (Magnetic Resonance Sounding) instrument. Thus, SBNMR is a cost-effective extension of the MRS method. Using a downhole sensor increases the depth of investigation and the resolution of MRS. In the near-horizontal Earth's magnetic field, the sensitive area of the sensor is represented by a cylinder of a few meters in diameter. A blind zone of 0.5 to 1 m around the borehole is due to the disturbance of the Earth's magnetic field by the magnetic core of the sensor. The relatively large volume investigated with SBNMR and the blind zone around borehole may represent an advantage of SBNMR over the NMR (nuclear magnetic resonance) borehole tool investigating a narrow zone around the borehole. However, using the Earth's magnetic field renders the SBNMR performance site dependent with an inherently low signal-to-noise ratio. Our first results show a good correspondence between SBNMR, MRS and borehole data.},
	language = {en},
	urldate = {2020-05-12},
	journal = {Journal of Applied Geophysics},
	author = {Legchenko, Anatoly and Texier, Benoît and Girard, Jean-François and Vouillamoz, Jean-Michel and Lawson, Fabrice Messan Amene and Alle, Iboukoun Christian and Baltassat, Jean-Michel and Pierrat, Ghislain and Boucher, Marie},
	month = jun,
	year = {2020},
	keywords = {SNMR, AMMA-CATCH, LMI REZOC, plateau Allada, MRS, SBNMR, Surface-borehole, Water content},
	pages = {104039},
}

@article{cappelaere_modeling_2020,
	title = {Modeling {Land} {Surface} {Fluxes} from {Uncertain} {Rainfall}: {A} {Case} {Study} in the {Sahel} with {Field}-{Driven} {Stochastic} {Rainfields}},
	volume = {11},
	issn = {2073-4433},
	shorttitle = {Modeling {Land} {Surface} {Fluxes} from {Uncertain} {Rainfall}},
	url = {https://www.mdpi.com/2073-4433/11/5/465},
	doi = {10.3390/atmos11050465},
	abstract = {In distributed land surface modeling (LSM) studies, uncertainty in the rainfields that are used to force models is a major source of error in predicted land surface response variables. This is particularly true for applications in the African Sahel region, where weak knowledge of highly time/space-variable convective rainfall in a poorly monitored region is a considerable obstacle to such developments. In this study, we used a field-based stochastic rainfield generator to analyze the propagation of the rainfall uncertainty through a distributed land surface model simulating water and energy fluxes in Sahelian ecosystems. Ensemble time/space rainfields were generated from field observations of the local AMMA-CATCH-Niger recording raingauge network. The rainfields were then used to force the SEtHyS-Savannah LSM, yielding an ensemble of time/space simulated fluxes. Through informative graphical representations and innovative diagnosis metrics, these outputs were analyzed to separate the different components of flux variability, among which was the uncertainty represented by ensemble-wise variability. Scale dependence was analyzed for each flux type in the water and energy budgets, producing a comprehensive picture of uncertainty propagation for the various flux types, with its relationship to intrinsic space/time flux variability. The study was performed over a 2530 km2 domain over six months, covering an entire monsoon season and the subsequent dry-down, using a kilometer/daily base resolution of analysis. The newly introduced dimensionless uncertainty measure, called the uncertainty coefficient, proved to be more effective in describing uncertainty patterns and relationships than a more classical measure based on variance fractions. Results show a clear scaling relationship in uncertainty coefficients between rainfall and the dependent fluxes, specific to each flux type. These results suggest a higher sensitivity to rainfall uncertainty for hydrological than for agro-ecological or meteorological applications, even though eddy fluxes do receive a substantial part of that source uncertainty.},
	language = {en},
	number = {5},
	urldate = {2020-10-22},
	journal = {Atmosphere},
	author = {Cappelaere, Bernard and Feurer, Denis and Vischel, Théo and Ottlé, Catherine and Issoufou, Hassane Bil-Assanou and Saux-Picart, Stéphane and Maïnassara, Ibrahim and Oï, Monique and Chazarin, Jean-Philippe and Barral, Hélène and Coudert, Benoit and Demarty, Jérôme},
	month = may,
	year = {2020},
	keywords = {AMMA-CATCH},
	pages = {465},
}

@article{dunn_development_2020,
	title = {Development of an {Updated} {Global} {Land} {In} {Situ}‐{Based} {Data} {Set} of {Temperature} and {Precipitation} {Extremes}: {HadEX3}},
	volume = {125},
	issn = {2169-897X, 2169-8996},
	shorttitle = {Development of an {Updated} {Global} {Land} {In} {Situ}‐{Based} {Data} {Set} of {Temperature} and {Precipitation} {Extremes}},
	url = {https://onlinelibrary.wiley.com/doi/10.1029/2019JD032263},
	doi = {10.1029/2019JD032263},
	language = {en},
	number = {16},
	urldate = {2020-10-22},
	journal = {Journal of Geophysical Research: Atmospheres},
	author = {Dunn, Robert J. H. and Alexander, Lisa V. and Donat, Markus G. and Zhang, Xuebin and Bador, Margot and Herold, Nicholas and Lippmann, Tanya and Allan, Rob and Aguilar, Enric and Barry, Abdoul Aziz and Brunet, Manola and Caesar, John and Chagnaud, Guillaume and Cheng, Vincent and Cinco, Thelma and Durre, Imke and Guzman, Rosaline and Htay, Tin Mar and Wan Ibadullah, Wan Maisarah and Bin Ibrahim, Muhammad Khairul Izzat and Khoshkam, Mahbobeh and Kruger, Andries and Kubota, Hisayuki and Leng, Tan Wee and Lim, Gerald and Li‐Sha, Lim and Marengo, Jose and Mbatha, Sifiso and McGree, Simon and Menne, Matthew and Milagros Skansi, Maria and Ngwenya, Sandile and Nkrumah, Francis and Oonariya, Chalump and Pabon‐Caicedo, Jose Daniel and Panthou, Gérémy and Pham, Cham and Rahimzadeh, Fatemeh and Ramos, Andrea and Salgado, Ernesto and Salinger, Jim and Sané, Youssouph and Sopaheluwakan, Ardhasena and Srivastava, Arvind and Sun, Ying and Timbal, Bertrand and Trachow, Nichanun and Trewin, Blair and Schrier, Gerard and Vazquez‐Aguirre, Jorge and Vasquez, Ricardo and Villarroel, Claudia and Vincent, Lucie and Vischel, Theo and Vose, Russ and Bin Hj Yussof, Mohd Noor'Arifin},
	month = aug,
	year = {2020},
	keywords = {AMMA-CATCH, ext1},
}

@article{descroix_are_2020,
	title = {Are the {Fouta} {Djallon} {Highlands} {Still} the {Water} {Tower} of {West} {Africa}?},
	volume = {12},
	issn = {2073-4441},
	url = {https://www.mdpi.com/2073-4441/12/11/2968},
	doi = {10.3390/w12112968},
	abstract = {A large share of surface water resources in Sahelian countries originates from Guinea’s Fouta Djallon highlands, earning the area the name of “the water tower of West Africa”. This paper aims to investigate the recent dynamics of the Fouta Djallon’s hydrological functioning. The evolution of the runoff and depletion coefficients are analyzed as well as their correlations with the rainfall and vegetation cover. The latter is described at three different space scales and with different methods. Twenty-five years after the end of the 1968–1993 major drought, annual discharges continue to slowly increase, nearly reaching a long-term average, as natural reservoirs which emptied to sustain streamflows during the drought have been replenishing since the 1990s, explaining the slow increase in discharges. However, another important trend has been detected since the beginning of the drought, i.e., the increase in the depletion coefficient of most of the Fouta Djallon upper basins, as a consequence of the reduction in the soil water-holding capacity. After confirming the pertinence and significance of this increase and subsequent decrease in the depletion coefficient, this paper identifies the factors possibly linked with the basins’ storage capacity trends. The densely populated areas of the summit plateau are also shown to be the ones where vegetation cover is not threatened and where ecological intensification of rural activities is ancient.},
	language = {en},
	number = {11},
	urldate = {2021-01-18},
	journal = {Water},
	author = {Descroix, Luc and Faty, Bakary and Manga, Sylvie Paméla and Diedhiou, Ange Bouramanding and A. Lambert, Laurent and Soumaré, Safietou and Andrieu, Julien and Ogilvie, Andrew and Fall, Ababacar and Mahé, Gil and Sombily Diallo, Fatoumata Binta and Diallo, Amirou and Diallo, Kadiatou and Albergel, Jean and Alkali Tanimoun, Bachir and Amadou, Ilia and Bader, Jean-Claude and Barry, Aliou and Bodian, Ansoumana and Boulvert, Yves and Braquet, Nadine and Couture, Jean-Louis and Dacosta, Honoré and Dejacquelot, Gwenaelle and Diakité, Mahamadou and Diallo, Kourahoye and Gallese, Eugenia and Ferry, Luc and Konaté, Lamine and Nka Nnomo, Bernadette and Olivry, Jean-Claude and Orange, Didier and Sakho, Yaya and Sambou, Saly and Vandervaere, Jean-Pierre},
	month = oct,
	year = {2020},
	keywords = {AMMA-CATCH, ext1},
	pages = {2968},
}

@article{zribi_new_2021,
	title = {A {New} {Reflectivity} {Index} for the {Retrieval} of {Surface} {Soil} {Moisture} {From} {Radar} {Data}},
	volume = {14},
	issn = {2151-1535},
	url = {https://ieeexplore.ieee.org/document/9237103},
	doi = {10.1109/JSTARS.2020.3033132},
	abstract = {A new approach based on the change detection technique is proposed for the estimation of surface soil moisture (SSM) from a time series of radar measurements. A new index of reflectivity (IR) is defined that uses radar signals and Fresnel coefficients. This index is equal to 0 in the case of the smallest value of the Fresnel coefficient, corresponding to the driest conditions and the weakest radar signal, and is equal to 1 for the highest value of the Fresnel coefficient, corresponding to the wettest soil conditions and the strongest radar signal. The integrated equation model is used to simulate the behavior of radar signals as a function of soil moisture and roughness. This approach validates the greater usefulness of the IR compared with that of the commonly used index of SSM (ISSM), which assumes that the SSM varies linearly as a function of radar signal strength. The IR-based approach was tested using Sentinel-1 radar data recorded over three regions: Banizombou (Niger), Merguellil (Tunisia), and Occitania (France). The IR approach was found to perform better for the estimation of SSM than the ISSM approach based on comparisons with ground measurements over bare soils.},
	journal = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing},
	author = {Zribi, M. and Foucras, M. and Baghdadi, N. and Demarty, J. and Muddu, S.},
	year = {2021},
	keywords = {Soil moisture, Spatial resolution, AMMA-CATCH, ext1, Change detection, index of reflectivity (IR), index of surface soil moisture (ISSM), Moisture, radar, Sentinel-1, Soil measurements, Spaceborne radar, surface soil moisture (SSM)},
	pages = {818--826},
}

@article{verbruggen_contrasting_2021,
	title = {Contrasting responses of woody and herbaceous vegetation to altered rainfall characteristics in the {Sahel}},
	volume = {18},
	issn = {1726-4170},
	url = {https://bg.copernicus.org/articles/18/77/2021/},
	doi = {https://doi.org/10.5194/bg-18-77-2021},
	abstract = {{\textbackslash}textlessp{\textbackslash}textgreater{\textbackslash}textlessstrong{\textbackslash}textgreaterAbstract.{\textbackslash}textless/strong{\textbackslash}textgreater Dryland ecosystems are a major source of land cover, account for about 40\% of Earth's terrestrial surface and net primary productivity, and house more than 30 \% of the human population. These ecosystems are subject to climate extremes (e.g. large-scale droughts and extreme floods) that are projected to increase in frequency and severity under most future climate scenarios. In this modelling study we assessed the impact of single years of extreme (high or low) rainfall on dryland vegetation in the Sahel. The magnitude and legacy of these impacts were quantified on both the plant functional type and the ecosystem levels. In order to understand the impact of differences in the rainfall distribution over the year, these rainfall anomalies were driven by changing either rainfall intensity, event frequency or rainy-season length. The Lund–Potsdam–Jena General Ecosystem Simulator (LPJ-GUESS) dynamic vegetation model was parameterized to represent dryland plant functional types (PFTs) and was validated against flux tower measurements across the Sahel. Different scenarios of extreme rainfall were derived from existing Sahel rainfall products and applied during a single year of the model simulation timeline. Herbaceous vegetation responded immediately to the different scenarios, while woody vegetation had a weaker and slower response, integrating precipitation changes over a longer timeframe. An increased season length had a larger impact than increased intensity or frequency, while impacts of decreased rainfall scenarios were strong and independent of the season characteristics. Soil control on surface water balance explains these contrasts between the scenarios. None of the applied disturbances caused a permanent vegetation shift in the simulations. Dryland ecosystems are known to play a dominant role in the trend and variability of the global terrestrial CO{\textbackslash}textlessspan class="inline-formula"{\textbackslash}textgreater$_{\textrm{2}}$\${\textbackslash}textless/span{\textbackslash}textgreater sink. We showed that single extremely dry and wet years can have a strong impact on the productivity of drylands ecosystems, which typically lasts an order of magnitude longer than the duration of the disturbance. Therefore, this study sheds new light on potential drivers and mechanisms behind this variability.{\textbackslash}textless/p{\textbackslash}textgreater},
	language = {English},
	number = {1},
	urldate = {2021-01-18},
	journal = {Biogeosciences},
	author = {Verbruggen, Wim and Schurgers, Guy and Horion, Stéphanie and Ardö, Jonas and Bernardino, Paulo N. and Cappelaere, Bernard and Demarty, Jérôme and Fensholt, Rasmus and Kergoat, Laurent and Sibret, Thomas and Tagesson, Torbern and Verbeeck, Hans},
	month = jan,
	year = {2021},
	keywords = {AMMA-CATCH, ext1},
	pages = {77--93},
}

@article{mathy_enjeux_2021,
	title = {Les enjeux de l’interdisciplinarité de la recherche et des parcours de formation sur le changement climatique : l’école d’été « {Autour} du 2 °{C} »},
	issn = {1240-1307, 1765-2979},
	shorttitle = {Les enjeux de l’interdisciplinarité de la recherche et des parcours de formation sur le changement climatique},
	url = {https://www.nss-journal.org/10.1051/nss/2021017},
	doi = {10.1051/nss/2021017},
	abstract = {En 2017 et 2019 ont eu lieu les deux premières éditions de l’école d’été « Autour du 2 °C » consacrée aux enjeux de l’interdisciplinarité de la recherche et des parcours de formation sur le changement climatique. Nous revenons dans ce texte sur les motivations qui ont conduit au lancement de cette initiative, ainsi que sur le positionnement et le déroulement de ces deux premières éditions, qui ont permis de mettre en évidence les défis scientifiques et sociopolitiques que soulève la mise en œuvre de l’interdisciplinarité dans la recherche, notamment sur un objet aussi protéiforme que le changement climatique. Ce texte constitue également une opportunité de faire le point sur les évolutions possibles de cette école au regard des enjeux sociétaux et scientifiques associés à la compréhension et à la gestion de l’impact des changements globaux sur notre environnement et sur nos sociétés. , In 2017 and 2019 there took place the first two editions of a Summer Seminar entitled “About the 2 °C” dedicated to the challenges of interdisciplinarity in research and training courses on climate change. In this paper, we focus on the motivations that led to launching this initiative, as well as to the positioning and progress of these first two editions, which highlighted the scientific and socio-political challenges raised by the implementation of interdisciplinarity in research, particularly regarding an object as protean as climate change. Besides, this paper provides a good opportunity to take stock of the possible evolutions of this Summer Seminar, given the societal and scientific challenges associated with the understanding and management of the impact of global changes on our environment and our societies.},
	urldate = {2021-06-02},
	journal = {Natures Sciences Sociétés},
	author = {Mathy, Sandrine and Labussière, Olivier and Lavorel, Sabine and Lebel, Thierry and Schmitt, Bertrand and le collectif « Autour du 2 °C 2019 », (incluant S. Galle et V. Wendling)},
	year = {2021},
	keywords = {AMMA-CATCH, ext1, LMI REZOC},
}

@article{chagnaud_unified_2021,
	title = {A unified statistical framework for detecting trends in multi-timescale precipitation extremes: application to non-stationary intensity-duration-frequency curves},
	volume = {145},
	issn = {1434-4483},
	shorttitle = {A unified statistical framework for detecting trends in multi-timescale precipitation extremes},
	url = {https://doi.org/10.1007/s00704-021-03650-9},
	doi = {10.1007/s00704-021-03650-9},
	abstract = {There is a large agreement that global warming induces changes of precipitation regimes of different nature and amplitude depending on the timescale considered. This question is of special concern regarding extreme rainfall that might have critical socio-environmental consequences. A unified framework is proposed here for detecting trends in extreme rainfall. It is based on the GEV distribution, whose parameters depend both on a simple scaling formulation to account for multiple time durations of rainfall and on time to account for the non-stationarity deriving from climatic trends. The implementation of the model is illustrated in the Sahel region by analyzing 30 in situ rainfall series of 28 years measured at time-steps from 2 to 24 h. While the separate analysis of the point series proves inconclusive for detecting trends at any of the time-steps considered, the inclusion of all the series and time-steps into the proposed unified model allows trends to be detected at a high level of confidence (p-value {\textless} 1\%). This trend essentially appears in the scale parameter of the regional GEV distribution, involving a 15 to 20\% increase of the 10-year rainfall in 28 years, and a 23 to 30\% increase of the 100-year rainfall. The main advantages of the proposed framework are (i) its parsimony, allowing for reducing the uncertainty associated with the model inference; (ii) its capacity for detecting trends either in the mean and/or in the variability of the extreme events; and (iii) its ability for producing non-stationary Intensity-Duration-Frequency curves that are coherent over a range of durations of accumulation.},
	language = {en},
	number = {1},
	urldate = {2021-06-10},
	journal = {Theoretical and Applied Climatology},
	author = {Chagnaud, Guillaume and Panthou, Geremy and Vischel, Théo and Blanchet, Juliette and Lebel, Thierry},
	month = jul,
	year = {2021},
	keywords = {AMMA-CATCH, LMI REZOC},
	pages = {839--860},
}

@article{senior_convection_2021,
	title = {Convection permitting regional climate change simulations for understanding future climate and informing decision making in {Africa}},
	issn = {0003-0007, 1520-0477},
	url = {https://journals.ametsoc.org/view/journals/bams/aop/BAMS-D-20-0020.1/BAMS-D-20-0020.1.xml},
	doi = {10.1175/BAMS-D-20-0020.1},
	abstract = {Abstract Pan-Africa convection-permitting regional climate model simulations have been performed to study the impact of high resolution and the explicit representation of atmospheric moist convection on the present and future climate of Africa. These unique simulations have allowed European and African climate scientists to understand the critical role that the representation of convection plays in the ability of a contemporary climate model to capture climate and climate change, including many impact relevant aspects such as rainfall variability and extremes. There are significant improvements in not only the small-scale characteristics of rainfall such as its intensity and diurnal cycle, but also in the large-scale circulation. Similarly effects of explicit convection affect not only projected changes in rainfall extremes, dry-spells and high winds, but also continental-scale circulation and regional rainfall accumulations. The physics underlying such differences are in many cases expected to be relevant to all models that use parameterized convection. In some cases physical understanding of small-scale change mean that we can provide regional decision makers with new scales of information across a range of sectors. We demonstrate the potential value of these simulations both as scientific tools to increase climate process understanding and, when used with other models, for direct user applications. We describe how these ground-breaking simulations have been achieved under the UK Government’s Future Climate for Africa Programme. We anticipate a growing number of such simulations, which we advocate should become a routine component of climate projection, and encourage international co-ordination of such computationally, and human-resource expensive simulations as effectively as possible.},
	urldate = {2021-06-10},
	journal = {Bulletin of the American Meteorological Society},
	author = {Senior, Catherine A and Marsham, John H and Berthou, Sègoléne and Burgin, Laura E and Folwell, Sonja S and Kendon, Elizabeth J and Klein, Cornelia M and Jones, Richard G and Mittal, Neha and Rowell, David P and Tomassini, Lorenzo and Vischel, Thèo and Becker, Bernd and Birch, Cathryn E and Crook, Julia and Dougill, Andrew J and Finney, Declan L and Graham, Richard J and Hart, Neil C G and Jack, Christopher D and Jackson, Lawrence S and James, Rachel and Koelle, Bettina and Misiani, Herbert and Mwalukanga, Brenda and Parker, Douglas J and Stratton, Rachel A and Taylor, Christopher M and Tucker, Simon O and Wainwright, Caroline M and Washington, Richard and Willet, Martin R},
	month = feb,
	year = {2021},
	keywords = {AMMA-CATCH, ext1},
	pages = {1--46},
}

@article{wilcox_stochastorm_2021,
	title = {Stochastorm: {A} {Stochastic} {Rainfall} {Simulator} for {Convective} {Storms}},
	volume = {22},
	issn = {1525-755X, 1525-7541},
	shorttitle = {Stochastorm},
	url = {https://journals.ametsoc.org/view/journals/hydr/22/2/jhm-d-20-0017.1.xml},
	doi = {10.1175/JHM-D-20-0017.1},
	abstract = {Abstract Stochastic rainfall generators aim to reproduce the main statistical features of rainfall at small spatial and temporal scales. The simulated synthetic rainfall series are recognized as suitable for use with impact analysis in water, agricultural, and ecological management. Convection-driven precipitation, dominant in certain regions of the world such as the intertropical belt regions, presents properties that require specific consideration when modeling: (i) strong rainfall intermittency, (ii) high variability of intensities within storms, (iii) strong spatiotemporal correlation of intensities, and (iv) marked seasonality of storm properties. In this article, improvements for an existing stochastic generator of rainfall fields that models convective storms are presented. Notable novelties include (i) the ability to model precipitation event timing, (ii) an improved temporal disaggregation scheme representing the rainfall distribution at subevent scales, and (iii) using covariates to reflect seasonal changes in precipitation occurrence and marginal distribution parameters. Extreme values are explicitly considered in the distribution of storm event intensities. The simulator is calibrated and validated using 28 years of 5-min precipitation data from the 30-rain-gauge AMMA-CATCH network in the Sahelian region of southwest Niger. Both large propagative systems and smaller local convective precipitation are generated. Results show that simulator improvements coherently represent the local climatology. The simulator can generate scenarios for impact studies with accurate representation of convective precipitation characteristics.},
	language = {English},
	number = {2},
	urldate = {2021-06-10},
	journal = {Journal of Hydrometeorology},
	author = {Wilcox, Catherine and Aly, Claire and Vischel, Théo and Panthou, Gérémy and Blanchet, Juliette and Quantin, Guillaume and Lebel, Thierry},
	month = feb,
	year = {2021},
	note = {Place: Boston MA, USA
Publisher: American Meteorological Society},
	keywords = {AMMA-CATCH, LMI REZOC},
	pages = {387--404},
}

@article{frappart_backscattering_2021,
	title = {Backscattering signatures at {Ka}, {Ku}, {C} and {S} bands from low resolution radar altimetry over land},
	volume = {68},
	issn = {02731177},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0273117720304774},
	doi = {10.1016/j.asr.2020.06.043},
	language = {en},
	number = {2},
	urldate = {2021-06-16},
	journal = {Advances in Space Research},
	author = {Frappart, Frédéric and Blarel, Fabien and Papa, Fabrice and Prigent, Catherine and Mougin, Eric and Paillou, Philippe and Baup, Frédéric and Zeiger, Pierre and Salameh, Edward and Darrozes, José and Bourrel, Luc and Rémy, Frédérique},
	month = jul,
	year = {2021},
	keywords = {AMMA-CATCH, ext1},
	pages = {989--1012},
}

@article{moumouni_impact_2021,
	title = {Impact of integration time steps of rain drop size distribution on their structuring and their modelling: a case study in northern {Benin}},
	volume = {353},
	issn = {1778-7025},
	shorttitle = {Impact of integration time steps of rain drop size distribution on their structuring and their modelling},
	url = {https://comptes-rendus.academie-sciences.fr/geoscience/articles/10.5802/crgeos.55/},
	doi = {10.5802/crgeos.55},
	language = {en},
	number = {1},
	urldate = {2021-06-23},
	journal = {Comptes Rendus Géosciences},
	author = {Moumouni, Sounmaïla and Adjikpé, Loïc Saturnin and Lawin, Agnidé Emmanuel},
	month = may,
	year = {2021},
	keywords = {AMMA-CATCH, LMI REZOC, Benin, disdrometer},
	pages = {135--153},
}

@article{colliander_validation_2021,
	title = {Validation of {Soil} {Moisture} {Data} {Products} from the {NASA} {SMAP} {Mission}},
	issn = {1939-1404, 2151-1535},
	url = {https://ieeexplore.ieee.org/document/9599364/},
	doi = {10.1109/JSTARS.2021.3124743},
	abstract = {NASA’s Soil Moisture Active Passive (SMAP) mission has been validating its soil moisture (SM) products since the start of data production on March 31, 2015. Prior to launch, the mission defined a set of criteria for core validation sites (CVS) that enable the testing of the key mission SM accuracy requirement (unbiased root-mean-square error},
	language = {en},
	urldate = {2021-06-25},
	journal = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing},
	author = {Colliander, Andreas and Reichle, Rolf and Crow, Wade and Cosh, Michael and Chen, Fan and Chan, Steven and Das, Narendra and Bindlish, Rajat and Chaubell, Julian and Kim, Seungbum and Liu, Qing and O'Neill, Peggy and Dunbar, Scott and Dang, Lan and Kimball, John and Jackson, Tom and AlJassar, Hala and Asanuma, Jun and Bhattacharya, Bimal and Berg, Aaron and Bosch, David and Bourgeau-Chavez, Laura and Caldwell, Todd and Calvet, Jean-Christophe and Collins, Chandra Holifield and Jensen, Karsten and Livingston, Stan and López-Baeza, Ernesto and Martínez-Fernández, José and McNairn, Heather and Moghaddam, Mahta and Montzka, Carsten and Notarnicola, Claudia and Pellarin, Thierry and Pfeil, Isabella and Pulliainen, Jouni and Ramos, Judith and Seyfrie, Mark and Starks, Patrick and Su, Z. and Thibeault, Marc and van der Velde, R. and Vreugdenhil, Mariette and Walker, Jeffrey and Zeng, Y. and Zribi, Mehrez and Entekhabi, Dara and Yueh, Simon},
	month = jun,
	year = {2021},
	keywords = {AMMA-CATCH, ext1, LMI REZOC, SMAP},
}

@article{outrequin_triple_2021,
	title = {The triple oxygen isotope composition of phytoliths, a new proxy of atmospheric relative humidity: controls of soil water isotope composition, temperature, {CO2} concentration and relative humidity},
	volume = {2021},
	issn = {1814-9359},
	shorttitle = {The triple oxygen isotope composition of phytoliths, a new proxy of atmospheric relative humidity},
	url = {https://cp.copernicus.org/preprints/cp-2021-34/},
	doi = {10.5194/cp-2021-34},
	abstract = {Abstract. Continental atmospheric relative humidity is a major climate parameter whose variability is poorly understood by global climate models. Models’improvement relies on model-data comparisons for past periods. However, there are no truly quantitative indicators of relative humidity for the pre-instrumental period. Previous studies highlighted a quantitative relationship between the triple oxygen isotope composition of phytoliths, and particularly the 17O-excess of phytoliths, and atmospheric relative humidity. Here, as part of a series of calibrations, we examine the respective controls of soil water isotope composition, temperature, CO2 concentration and relative humidity on phytolith 17O-excess. For that purpose, the grass species Festuca arundinacea was grown in growth chambers where these parameters were varying. The setup was designed to control the evolution of the triple oxygen isotope composition of phytoliths and all the water compartments of the soil-plant-atmosphere continuum. Different analytical techniques (cavity ring-down spectroscopy and isotope ratio mass spectrometry) were used to analyse water and silica. An inter-laboratory comparison allowed to strengthen the isotope data matching. Water and phytolith isotope compositions were compared to previous datasets obtained from growth chamber and natural tropical sites. The results show that the δ'18O value of the source water governs the starting point from which the triple oxygen isotope composition of leaf water, phytolith-forming water and phytoliths evolve. However, since the 17O-excess varies little in the growth chamber and natural source waters, this has no impact on the strong relative humidity-dependency of the 17O-excess of phytoliths, demonstrated for the 40–80 \% relative humidity range. This relative humidity-dependency is not impacted by changes in air temperature or CO2 concentration either. A relative humidity proxy equation is proposed. Each per meg of change in phytolith 17O-excess reflects a change in atmospheric relative humidity of ca. 0.2 \%. The ±15 per meg reproducibility on the measurement of phytolith 17O-excess corresponds to a ± 3.6 \% precision on the reconstructed relative humidity. The low sensitivity of phytolith 17O-excess to climate parameters other than relative humidity makes it particularly suitable for quantitative reconstructions of continental relative humidity changes in the past.},
	urldate = {2021-07-05},
	journal = {Climate of the Past Discussion},
	author = {Outrequin, Clément and Alexandre, Anne and Vallet-Coulomb, Christine and Piel, Clément and Devidal, Sébastien and Landais, Amaelle and Couapel, Martine and Mazur, Jean-Charles and Peugeot, Christophe and Pierre, Monique and Prié, Frédéric and Roy, Jacques and Sonzogni, Corinne and Voigt, Claudia},
	month = apr,
	year = {2021},
	keywords = {AMMA-CATCH, ext1, LMI REZOC},
}

@article{delogu_evaluation_2021,
	title = {Evaluation of {Multiple} {Methods} for the {Production} of {Continuous} {Evapotranspiration} {Estimates} from {TIR} {Remote} {Sensing}},
	volume = {13},
	issn = {2072-4292},
	url = {https://www.mdpi.com/2072-4292/13/6/1086},
	doi = {10.3390/rs13061086},
	abstract = {Continuous daily estimates of evapotranspiration (ET) spatially distributed at plot scale are required to monitor the water loss and manage crop irrigation needs. Remote sensing approaches in the thermal infrared (TIR) domain are relevant to assess actual ET and soil moisture status but due to lengthy return intervals and cloud cover, data acquisition is not continuous over time. This study aims to assess the performances of 6 commonly used as well as two new reference quantities including rainfall as an index of soil moisture availability to reconstruct seasonal ET from sparse estimates and as a function of the revisit frequency. In a first step, instantaneous in situ eddy-covariance flux tower data collected over multiple ecosystems and climatic areas were used as a proxy for perfect retrievals on satellite overpass dates. In a second step, instantaneous estimations at the time of satellite overpass were produced using the Soil Plant Atmosphere and Remote Sensing Evapotranspiration (SPARSE) energy balance model in order to evaluate the errors concurrent to the use of an energy balance model simulating the instantaneous IRT products from the local surface temperature. Significant variability in the performances from site to site was observed particularly for long revisit frequencies over 8 days, suggesting that the revisit frequency necessary to achieve accurate estimates of ET via temporal upscaling needs to be fewer than 8 days whatever the reference quantity used. For shorter return interval, small differences among the interpolation techniques and reference quantities were found. At the seasonal scale, very simple methods using reference quantities such as the global radiation or clear sky radiation appeared relevant and robust against long revisit frequencies. For infra-seasonal studies targeting stress detection and irrigation management, taking the amount of precipitation into account seemed necessary, especially to avoid the underestimation of ET over cloudy days during a long period without data acquisitions.},
	language = {en},
	number = {6},
	urldate = {2021-07-05},
	journal = {Remote Sensing},
	author = {Delogu, Emilie and Olioso, Albert and Alliès, Aubin and Demarty, Jérôme and Boulet, Gilles},
	month = mar,
	year = {2021},
	keywords = {AMMA-CATCH, ext1},
	pages = {1086},
}

@article{macdonald_mapping_2021,
	title = {Mapping groundwater recharge in {Africa} from ground observations and implications for water security},
	volume = {16},
	issn = {1748-9326},
	url = {https://doi.org/10.1088/1748-9326/abd661},
	doi = {10.1088/1748-9326/abd661},
	abstract = {Groundwater forms the basis of water supplies across much of Africa and its development is rising as demand for secure water increases. Recharge rates are a key component for assessing groundwater development potential, but have not been mapped across Africa, other than from global models. Here we quantify long-term average (LTA) distributed groundwater recharge rates across Africa for the period 1970–2019 from 134 ground-based estimates and upscaled statistically. Natural diffuse and local focussed recharge, where this mechanism is widespread, are included but discrete leakage from large rivers, lakes or from irrigation are excluded. We find that measurable LTA recharge is found in most environments with average decadal recharge depths in arid and semi-arid areas of 60 mm (30–140 mm) and 200 mm (90–430 mm) respectively. A linear mixed model shows that at the scale of the African continent only LTA rainfall is related to LTA recharge—the inclusion of other climate and terrestrial factors do not improve the model. Kriging methods indicate spatial dependency to 900 km suggesting that factors other than LTA rainfall are important at local scales. We estimate that average decadal recharge in Africa is 15 000 km3 (4900–45 000 km3), approximately 2\% of estimated groundwater storage across the continent, but is characterised by stark variability between high-storage/low-recharge sedimentary aquifers in North Africa, and low-storage/high-recharge weathered crystalline-rock aquifers across much of tropical Africa. African water security is greatly enhanced by this distribution, as many countries with low recharge possess substantial groundwater storage, whereas countries with low storage experience high, regular recharge. The dataset provides a first, ground-based approximation of the renewability of groundwater storage in Africa and can be used to refine and validate global and continental hydrological models while also providing a baseline against future change.},
	language = {en},
	number = {3},
	urldate = {2021-07-08},
	journal = {Environmental Research Letters},
	author = {MacDonald, Alan M. and Lark, R. Murray and Taylor, Richard G. and Abiye, Tamiru and Fallas, Helen C. and Favreau, Guillaume and Goni, Ibrahim B. and Kebede, Seifu and Scanlon, Bridget and Sorensen, James P. R. and Tijani, Moshood and Upton, Kirsty A. and West, Charles},
	month = feb,
	year = {2021},
	keywords = {AMMA-CATCH, ext1},
	pages = {034012},
}

@article{massazza_recent_2021,
	title = {Recent {Changes} in {Hydroclimatic} {Patterns} over {Medium} {Niger} {River} {Basins} at the {Origin} of the 2020 {Flood} in {Niamey} ({Niger})},
	volume = {13},
	copyright = {http://creativecommons.org/licenses/by/3.0/},
	issn = {2073-4441},
	url = {https://www.mdpi.com/2073-4441/13/12/1659},
	doi = {10.3390/w13121659},
	abstract = {Niamey, the capital of Niger, is particularly prone to floods, since it is on the banks of the Niger River, which in its middle basin has two flood peaks: one in summer (the red flood) and one in winter (the black flood). In 2020, the Niger River in Niamey reached its all-time highest levels following an abundant rainy season. On the other hand, the floods in Niamey have been particularly frequent in the last decade, a symptom of a change in hydroclimatic behaviour already observed since the end of the great droughts of the 1970s and 1980s and which is identified with the name of Sahelian Paradox. This study, starting from the analysis of the 2020 flood and from the update of the rating curve of the Niamey hydrometric station, analyses the rainfall–runoff relationship on the Sahelian basins of the Medium Niger River Basin (MNRB) that are at the origin of the local flood. The comparative analysis of runoffs, annual maximum flows (AMAX) and runoff coefficients with various rainfall indices calculated on gridded datasets allowed to hydroclimatically characterise the last decade as a different period from the wet one before the drought, the dry one and the post-drought one. Compared to the last one, the current period is characterised by a sustained increase in hydrological indicators (AMAX +27\%) consistent with the increase in both the accumulation of precipitation (+11\%) and the number (+51\%) and magnitude (+54\%) of extreme events in the MNRB. Furthermore, a greater concentration of rainfall and extremes (+78\%) in August contributes to reinforcing the red flood’s positive anomalies (+2.23 st.dev in 2020). The study indicates that under these conditions the frequency of extreme hydrological events in Niamey will tend to increase further also because of the concurrence of drivers such as river-bed silting and levee effects. Consequently, the study concludes with the need for a comprehensive flood-risk assessment on the Niamey city that considers both recent hydroclimatic trends and urbanisation dynamics in flood zones hence defining the most appropriate risk-reduction strategies.},
	language = {en},
	number = {12},
	urldate = {2021-07-08},
	journal = {Water},
	author = {Massazza, Giovanni and Bacci, Maurizio and Descroix, Luc and Ibrahim, Mohamed Housseini and Fiorillo, Edoardo and Katiellou, Gaptia Lawan and Panthou, Geremy and Pezzoli, Alessandro and Rosso, Maurizio and Sauzedde, Elisa and Terenziani, Andrea and De Filippis, Tiziana and Rocchi, Leandro and Burrone, Sara and Tiepolo, Maurizio and Vischel, Théo and Tarchiani, Vieri},
	month = jan,
	year = {2021},
	keywords = {Sahel, floods, AMMA-CATCH, ext1, CHIRPS, early warning system, flood risk, hazard thresholds, inondation 2020, levees, Middle Niger River Basin, Niamey, rating curves, runoff coefficients, TerraClimate},
	pages = {1659},
}

@article{rahimi_modeling_2021,
	title = {Modeling gas exchange and biomass production in {West} {African} {Sahelian} and {Sudanian} ecological zones},
	volume = {14},
	issn = {1991-9603},
	url = {https://gmd.copernicus.org/articles/14/3789/2021/},
	doi = {10.5194/gmd-14-3789-2021},
	abstract = {Abstract. West African Sahelian and Sudanian ecosystems provide essential services to people and also play a significant role within the global carbon cycle. However, climate and land use are dynamically changing, and uncertainty remains with respect to how these changes will affect the potential of these regions to provide food and fodder resources or how they will affect the biosphere–atmosphere exchange of CO2. In this study, we investigate the capacity of a process-based biogeochemical model, LandscapeDNDC, to simulate net ecosystem exchange (NEE) and aboveground biomass of typical managed and natural Sahelian and Sudanian savanna ecosystems. In order to improve the simulation of phenology, we introduced soil-water availability as a common driver of foliage development and productivity for all of these systems. The new approach was tested by using a sample of sites (calibration sites) that provided NEE from flux tower observations as well as leaf area index data from satellite images (MODIS, MODerate resolution Imaging Spectroradiometer). For assessing the simulation accuracy, we applied the calibrated model to 42 additional sites (validation sites) across West Africa for which measured aboveground biomass data were available. The model showed good performance regarding biomass of crops, grass, or trees, yielding correlation coefficients of 0.82, 0.94, and 0.77 and root-mean-square errors of 0.15, 0.22, and 0.12 kg m−2, respectively. The simulations indicate aboveground carbon stocks of up to 0.17, 0.33, and 0.54 kg C ha−1 m−2 for agricultural, savanna grasslands, and savanna mixed tree–grassland sites, respectively. Carbon stocks and exchange rates were particularly correlated with the abundance of trees, and grass biomass and crop yields were higher under more humid climatic conditions. Our study shows the capability of LandscapeDNDC to accurately simulate carbon balances in natural and agricultural ecosystems in semiarid West Africa under a wide range of conditions; thus, the model could be used to assess the impact of land-use and climate change on the regional biomass productivity.},
	language = {en},
	number = {6},
	urldate = {2021-07-27},
	journal = {Geoscientific Model Development},
	author = {Rahimi, Jaber and Ago, Expedit Evariste and Ayantunde, Augustine and Berger, Sina and Bogaert, Jan and Butterbach-Bahl, Klaus and Cappelaere, Bernard and Cohard, Jean-Martial and Demarty, Jérôme and Diouf, Abdoul Aziz and Falk, Ulrike and Haas, Edwin and Hiernaux, Pierre and Kraus, David and Roupsard, Olivier and Scheer, Clemens and Srivastava, Amit Kumar and Tagesson, Torbern and Grote, Rüdiger},
	month = jun,
	year = {2021},
	keywords = {AMMA-CATCH, ext1, LMI REZOC},
	pages = {3789--3812},
}

@article{malam_abdou_comparative_2021,
	title = {Comparative hydrodynamic study of granitic and sedimentary catchments in {Western} {Niger}},
	volume = {66},
	issn = {0262-6667, 2150-3435},
	url = {https://www.tandfonline.com/doi/full/10.1080/02626667.2021.1921181},
	doi = {10.1080/02626667.2021.1921181},
	language = {en},
	number = {10},
	urldate = {2021-07-29},
	journal = {Hydrological Sciences Journal},
	author = {Malam Abdou, Moussa and Vandervaere, Jean-Pierre and Descroix, Luc and Bouzou Moussa, Ibrahim},
	month = jul,
	year = {2021},
	keywords = {AMMA-CATCH, LMI REZOC, Niger},
	pages = {1541--1551},
}

@article{davies_variability_2021,
	title = {Variability in {Surface} {Radiative} {Fluxes} over {West} {Africa} using {Wavelet} and {Principal} {Component} {Analyses}},
	journal = {Journal of Applied Meteorology and Climatology},
	author = {Davies, P. and Mamadou, O. and Quansah, E. and Aryee, J.N.A. and Atiah, W.A. and Amekudzi, L.K. and Sam, F. and Galle, S. and Demarty, J.},
	month = sep,
	year = {2021},
	keywords = {AMMA-CATCH, LMI REZOC},
	pages = {JAMC--D--21--0187),},
}

@article{diepkile_validation_2021,
	title = {Validation of the altimetry-based water levels from {Sentinel}-{3A} and {B} in the {Inner} {Niger} {Delta}},
	volume = {384},
	issn = {2199-899X},
	url = {https://piahs.copernicus.org/articles/384/31/2021/},
	doi = {10.5194/piahs-384-31-2021},
	abstract = {Abstract. The comprehension of water level fluctuations and the sustainability of the Inner Niger River Delta (IND) is a major concern for the scientific community, but also for the local population. Located in the centre of Mali, the heart of the Sahel, the delta is characterised by a floodable area of more than 32 000 km2 during the rainy season, which contributes very strongly to the vitality of local ecosystem, and is consequently classified as a Ramsar site under the international Convention for Wetlands. In addition, the Delta acts as an environmental and socio-economic development barometer for the entire sub-region. Nowadays, we can observe an increasing fragility of the delta due to climate change, desertification and human activities, and justifies the need for permanent monitoring. The present study is based on the recent successes of radar altimetry, originally designed to monitor the dynamics topography of the ocean, and now very frequently used to retrieve inland water levels, of lakes, rivers, and wetlands. Previous studies evaluated the performances of several radar altimetry missions including Low Resolution Mode (LRM) (Topex-Poseidon, Jason-1/2/3, ERS-2, ENVISAT, and SARAL, and Synthetic Aperture Radar (SAR) Sentinel-3A missions for water level retrievals over 1992–2017. More than 50 times series of water levels were build at the crossing between water bodies and Sentinel-3A and 3B over 2016–2020. Twenty-four comparisons between in-situ and altimetry-based time-series of water levels were achieved over the IND. RMSE generally lower than 0.7 m and r higher than 0.9 were obtained.},
	language = {en},
	urldate = {2021-11-16},
	journal = {Proceedings of the International Association of Hydrological Sciences},
	author = {Diepkilé, Adama Telly and Egon, Flavien and Blarel, Fabien and Mougin, Eric and Frappart, Frédéric},
	month = nov,
	year = {2021},
	keywords = {AMMA-CATCH},
	pages = {31--35},
}

@article{fovet_intermittent_2021,
	title = {Intermittent rivers and ephemeral streams: {Perspectives} for critical zone science and research on socio‐ecosystems},
	volume = {8},
	issn = {2049-1948},
	shorttitle = {Intermittent rivers and ephemeral streams},
	url = {https://doi.org/10.1002/wat2.1523},
	doi = {10.1002/wat2.1523},
	abstract = {Abstract Intermittent rivers and ephemeral streams (IRES) are now recognized to support specific freshwater biodiversity and ecosystem services and represent approximately half of the global river network, a fraction that is likely to increase in the context of global changes. Despite large research efforts on IRES during the past few decades, there is a need for developing a systemic approach to IRES that considers their hydrological, hydrogeological, hydraulic, ecological, and biogeochemical properties and processes, as well as their interactions with human societies. Thus, we assert that the interdisciplinary approach to ecosystem research promoted by critical zone sciences and socio-ecology is relevant. These approaches rely on infrastructure?Critical Zone Observatories (CZO) and Long-Term Socio-Ecological Research (LTSER) platforms?that are representative of the diversity of IRES (e.g., among climates or types of geology. We illustrate this within the French CZO and LTSER, including their diversity as socio-ecosystems, and detail human interactions with IRES. These networks are also specialized in the long-term observations required to detect and measure ecosystem responses of IRES to climate and human forcings despite the delay and buffering effects within ecosystems. The CZO and LTSER platforms also support development of innovative techniques and data analysis methods that can improve characterization of IRES, in particular for monitoring flow regimes, groundwater-surface water flow, or water biogeochemistry during rewetting. We provide scientific and methodological perspectives for which this interdisciplinary approach and its associated infrastructure would provide relevant and original insights that would help fill knowledge gaps about IRES. This article is categorized under: Water and Life {\textgreater} Stresses and Pressures on Ecosystems Science of Water {\textgreater} Hydrological Processes Water and Life {\textgreater} Conservation, Management, and Awareness},
	language = {en},
	number = {4},
	urldate = {2021-11-16},
	journal = {WIREs Water},
	author = {Fovet, Ophelie and Belemtougri, Axel and Boithias, Laurie and Braud, Isabelle and Charlier, Jean‐Baptiste and Cottet, Marylise and Daudin, Kevin and Dramais, Guillaume and Ducharne, Agnès and Folton, Nathalie and Grippa, Manuela and Hector, Basile and Kuppel, Sylvain and Le Coz, Jérôme and Legal, Luc and Martin, Philippe and Moatar, Florentina and Molénat, Jérôme and Probst, Anne and Riotte, Jean and Vidal, Jean‐Philippe and Vinatier, Fabrice and Datry, Thibault},
	month = jul,
	year = {2021},
	keywords = {AMMA-CATCH, LMI REZOC, critical zone observatories, long-term socio-ecosystem research, nonperennial, systemic approach, temporary waterways},
	pages = {e1523},
}

@article{boucher_estimating_2009,
	title = {Estimating specific yield and transmissivity with magnetic resonance sounding in an unconfined sandstone aquifer ({Niger})},
	volume = {17},
	issn = {1435-0157},
	url = {http://www.springerlink.com/content/54016584u6561314/},
	doi = {10.1007/s10040-009-0447-x},
	abstract = {The unconfined aquifer of the Continental Terminal in Niger was investigated by magnetic resonance sounding (MRS) and by 14 pumping tests in order to improve calibration of MRS outputs at field scale. The reliability of the standard relationship used for estimating aquifer transmissivity by MRS was checked; it was found that the parametric factor can be estimated with an uncertainty ≤150\% by a single point of calibration. The MRS water content (θMRS) was shown to be positively correlated with the specific yield (Sy), and θMRS always displayed higher values than Sy. A conceptual model was subsequently developed, based on estimated changes of the total porosity, Sy, and the specific retention Sr as a function of the median grain size. The resulting relationship between θMRS and Sy showed a reasonably good fit with the experimental dataset, considering the inherent heterogeneity of the aquifer matrix (residual error is ∼60\%). Interpreted in terms of aquifer parameters, MRS data suggest a log-normal distribution of the permeability and a one-sided Gaussian distribution of Sy. These results demonstrate the efficiency of the MRS method for fast and low-cost prospection of hydraulic parameters for large unconfined aquifers.},
	number = {7},
	journal = {Hydrogeology Journal},
	author = {Boucher, M. and Favreau, G. and Vouillamoz, J. M. and Nazoumou, Y. and Legchenko, A.},
	month = apr,
	year = {2009},
	keywords = {AMMA-CATCH, Niger, HYBIS, Recharge, semiarid niger, flow, Hydraulic properties, Magnetic Resonance Sounding (MRS), mrs, Pumping test, reservoir, Sedimentary rocks},
	pages = {1805--1815},
}

@article{brandt_reduction_2018,
	title = {Reduction of tree cover in {West} {African} woodlands and promotion in semi-arid farmlands},
	volume = {11},
	issn = {1752-0908},
	url = {http://www.nature.com/articles/s41561-018-0092-x},
	doi = {10.1038/s41561-018-0092-x},
	abstract = {Woody vegetation in farmland acts as a carbon sink and provides ecosystem services for local people, but no macroscale assessments of the impact of management and climate on woody cover exist for drylands. Here we make use of very high spatial resolution satellite imagery to derive wall-to-wall woody cover patterns in tropical West African drylands. Our study reveals that mean woody cover in farmlands along all semi-arid and sub-humid rainfall zones is 16\%, on average only 6\% lower than in savannahs. In semi-arid Sahel, farmland management promotes woody cover around villages (11\%), while neighbouring savannahs had on average less woody cover. However, farmlands in sub-humid zones have a greatly reduced woody cover (21\%) as compared with savannahs (33\%). In the region as a whole, rainfall, terrain and soil are the most important (80\%) determinants of woody cover, while management factors play a smaller (20\%) role. We conclude that agricultural expansion causes a considerable reduction of trees in woodlands, but observations in Sahel indicate that villagers safeguard trees on nearby farmlands which contradicts simplistic ideas of a high negative correlation between population density and woody cover.},
	language = {en},
	number = {5},
	journal = {Nature Geoscience},
	author = {Brandt, Martin and Rasmussen, Kjeld and Hiernaux, Pierre and Herrmann, Stefanie and Tucker, Compton J. and Tong, Xiaoye and Tian, Feng and Mertz, Ole and Kergoat, Laurent and Mbow, Cheikh and David, John L. and Melocik, Katherine A. and Dendoncker, Morgane and Vincke, Caroline and Fensholt, Rasmus},
	month = may,
	year = {2018},
	keywords = {Sahel, AMMA-CATCH, ext1, Niger, Mali, Senegal},
	pages = {328--333},
}

@article{braud_unidimensional_1997,
	title = {Unidimensional modelling of a fallow savannah during the {HAPEX}-{Sahel} experiment using the {SiSPAT} model},
	volume = {188-189},
	url = {http://www.sciencedirect.com/science/article/B6V6C-4D03X01-1J/2/1f6072bdb5973bd9088ac569b3312d76},
	doi = {10.1016/S0022-1694(96)03177-0},
	abstract = {In the framework of the HAPEX-Sahel experiment, a data set was gathered on a fallow savannah site of the Central East Supersite. This includes 54 days of atmospheric forcing (air temperature and humidity, wind speed, solar and long-wave radiation and rainfall), net radiation, sensible, latent and soil heat fluxes and soil temperature series at a time step of 20 min. Furthermore, 17 soil moisture profiles, the evolution of the leaf area indices and some soil characteristics were available. The data set was used, at the field scale, to calibrate and validate the SiSPAT (simple soil plant atmosphere transfer) model, a 1D model of coupled heat and mass transfer in the soil-plant-atmosphere continuum. The objectives of the study were (i) to assess the performances of the model in the prediction of the diurnal cycle of net radiation, turbulent fluxes, soil temperatures and the evolution of soil water content over a period of 54 days (day of the year 239-292, 1992), characterized by early stage intense rainfall events and fast drying afterwards, (ii) to analyse the influence of soil surface crust on the water balance and (iii) to identify the 1D modelling limits when the surface area consists of two strates: a ground sparse herb layer, characterized by a large spatial variability of surface properties and water content with scattered bushes. The model was calibrated over a 2-week period and then run over the whole 54-day period. We were able to reproduce the main characteristics of the observed net radiation, turbulent fluxes, soil temperature and soil moisture for the intense rainfall events and for an elongated dry period. Nevertheless, when the crust was not taken into account, the rainfall-runoff-infiltration process and the evapotranspiration after rain were poorly predicted (overestimation of evapotranspiration of infiltration). When a crust was considered to model the water balance at the field scale, its influence was found to be substantial on the runoff generation and the infiltration, and consequently on the bare soil evaporation. However, runoff predictions were much larger than the observations. Indeed, at the field scale, no runoff was generally observed. Lateral redistribution of water between crusted and noncrusted zones was observed in the plot. However, this cannot be taken into account with the presented 1D deterministic modelling. Hence further model development is needed to yield a better representation of soil water fluxes at the field scale.},
	journal = {Journal of Hydrology},
	author = {Braud, I. and Bessemoulin, P. and Monteny, B. and Sicot, M. and Vandervaere, J. P. and Vauclin, M.},
	month = feb,
	year = {1997},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {912--945},
}

@article{chagnaud_synthetic_2022,
	title = {A synthetic view of rainfall intensification in the {West} {African} {Sahel}},
	volume = {17},
	issn = {1748-9326},
	url = {http://dx.doi.org/10.1088/1748-9326/ac4a9c},
	doi = {10.1088/1748-9326/ac4a9c},
	abstract = {The West African Sahel has been facing for more than 30 years an increase in extreme rainfall with strong socio-economic impacts. This situation challenges decision-makers to define adaptation strategies in a rapidly changing climate. The present study proposes (i) a quantitative characterization of the trends in extreme rainfall at the regional scale, (ii) the translation of the trends into metrics that can be used by hydrological risk managers, (iii) elements for understanding the link between the climatology of extreme and mean rainfall. Based on a regional non-stationary statistical model applied to in-situ daily rainfall data over the period 1983–2015, we show that the region-wide increasing trend in extreme rainfall is highly significant. The change in extreme value distribution reflects an increase in both the mean and variability, producing a 5\%/decade increase in extreme rainfall intensity whatever the return period. The statistical framework provides operational elements for revising the design methods of hydraulic structures which most often assume a stationary climate. Finally, the study shows that the increase in annual maxima of daily rainfall is more attributable to stronger storm intensities (80\%) than to more frequent storm occurrences (20\%), reflecting a major rainfall regime shift in comparison to those observed in the region since 1950.},
	number = {4},
	journal = {Environmental Research Letters},
	author = {Chagnaud, G. and Panthou, G. and Vischel, T. and Lebel, T.},
	month = mar,
	year = {2022},
	keywords = {AMMA-CATCH, LMI REZOC},
	pages = {044005},
}

@article{colliander_validation_2017,
	title = {Validation of {SMAP} surface soil moisture products with core validation sites},
	volume = {191},
	issn = {0034-4257},
	url = {https://www.sciencedirect.com/science/article/pii/S0034425717300329},
	doi = {10.1016/j.rse.2017.01.021},
	abstract = {The NASA Soil Moisture Active Passive (SMAP) mission has utilized a set of core validation sites as the primary methodology in assessing the soil moisture retrieval algorithm performance. Those sites provide well-calibrated in situ soil moisture measurements within SMAP product grid pixels for diverse conditions and locations. The estimation of the average soil moisture within the SMAP product grid pixels based on in situ measurements is more reliable when location specific calibration of the sensors has been performed and there is adequate replication over the spatial domain, with an up-scaling function based on analysis using independent estimates of the soil moisture distribution. SMAP fulfilled these requirements through a collaborative Cal/Val Partner program. This paper presents the results from 34 candidate core validation sites for the first eleven months of the SMAP mission. As a result of the screening of the sites prior to the availability of SMAP data, out of the 34 candidate sites 18 sites fulfilled all the requirements at one of the resolution scales (at least). The rest of the sites are used as secondary information in algorithm evaluation. The results indicate that the SMAP radiometer-based soil moisture data product meets its expected performance of 0.04m3/m3 volumetric soil moisture (unbiased root mean square error); the combined radar-radiometer product is close to its expected performance of 0.04m3/m3, and the radar-based product meets its target accuracy of 0.06m3/m3 (the lengths of the combined and radar-based products are truncated to about 10weeks because of the SMAP radar failure). Upon completing the intensive Cal/Val phase of the mission the SMAP project will continue to enhance the products in the primary and extended geographic domains, in co-operation with the Cal/Val Partners, by continuing the comparisons over the existing core validation sites and inclusion of candidate sites that can address shortcomings.},
	language = {en},
	journal = {Remote Sensing of Environment},
	author = {Colliander, A. and Jackson, T. J. and Bindlish, R. and Chan, S. and Das, N. and Kim, S. B. and Cosh, M. H. and Dunbar, R. S. and Dang, L. and Pashaian, L. and Asanuma, J. and Aida, K. and Berg, A. and Rowlandson, T. and Bosch, D. and Caldwell, T. and Caylor, K. and Goodrich, D. and al Jassar, H. and Lopez-Baeza, E. and Martínez-Fernández, J. and González-Zamora, A. and Livingston, S. and McNairn, H. and Pacheco, A. and Moghaddam, M. and Montzka, C. and Notarnicola, C. and Niedrist, G. and Pellarin, T. and Prueger, J. and Pulliainen, J. and Rautiainen, K. and Ramos, J. and Seyfried, M. and Starks, P. and Su, Z. and Zeng, Y. and van der Velde, R. and Thibeault, M. and Dorigo, W. and Vreugdenhil, M. and Walker, J. P. and Wu, X. and Monerris, A. and O'Neill, P. E. and Entekhabi, D. and Njoku, E. G. and Yueh, S.},
	month = mar,
	year = {2017},
	keywords = {Validation, Soil moisture, AMMA-CATCH, ext1, SMAP, AO, PHYREV, phyrev, CAL/VAL},
	pages = {215--231},
}

@article{dorigo_global_2013,
	title = {Global {Automated} {Quality} {Control} of {In} {Situ} {Soil} {Moisture} {Data} from the {International} {Soil} {Moisture} {Network}},
	volume = {12},
	issn = {1539-1663},
	url = {https://acsess.onlinelibrary.wiley.com/doi/abs/10.2136/vzj2012.0097},
	doi = {10.2136/vzj2012.0097},
	abstract = {The International Soil Moisture Network (ISMN) was initiated in 2009 to support calibration and validation of remote sensing products and land surface models, and to facilitate studying the behavior of our climate over space and time. The ISMN does this by collecting and harmonizing soil moisture data sets from a large variety of individually operating networks and making them available through a centralized data portal. Due to the diversity of climatological conditions covered by the stations and differences in measurement devices and setup, the quality of the measurements is highly variable. Therefore, appropriate quality characterization is desirable for a correct use of the data sets. This study presents a new, automated quality control system for soil moisture measurements contained in the ISMN. Two types of quality control procedures are presented. The first category is based on the geophysical dynamic range and consistency of the measurements. It includes flagging values exceeding a certain threshold and checking the validity of soil moisture variations in relation to changes in soil temperature and precipitation. In particular, the usability of global model- or remote sensing–based temperature and precipitation data sets were tested for this purpose as an alternative to in situ measurements, which are often not recorded at the soil moisture sites themselves. The second category of procedures analyzes the shape of the soil moisture time series to detect outliers (spikes), positive and negative breaks, saturation of the signal, and unresponsive sensors. All methods were first validated and then applied to all the data sets currently contained in the ISMN. A validation example of an AMSR-E satellite and a GLDAS-Noah model product showed a small but positive impact of the flagging. On the basis of the positive results of this study we will add the flags as a standard attribute to all soil moisture measurements contained in the ISMN.},
	number = {3},
	journal = {Vadose Zone Journal},
	author = {Dorigo, W.A. and Xaver, A. and Vreugdenhil, M. and Gruber, A. and Hegyiová, A. and Sanchis-Dufau, A.D. and Zamojski, D. and Cordes, C. and Wagner, W. and Drusch, M.},
	year = {2013},
	keywords = {AMMA-CATCH, extérieur, International Soil Moisture Network, ISMN, Climate Prediction Center’s operation global 2.5° 5-d Merged Analysis of Precipitation, CMAP, Harmonized World Soil Database, HWSD, near real time, NRT, QC, quality control},
	pages = {vzj2012.0097},
}

@article{grippa_land_2011,
	title = {Land water storage variability over {West} {Africa} estimated by {Gravity} {Recovery} and {Climate} {Experiment} ({GRACE}) and land surface models},
	volume = {47},
	issn = {0043-1397},
	url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2009WR008856},
	doi = {10.1029/2009WR008856},
	abstract = {Land water storage plays a fundamental role in the West African water cycle and has an important impact on climate and on the natural resources of this region. However, measurements of land water storage are scarce at regional and global scales and especially in poorly instrumented endorheic regions, such as most of the Sahel, where little useful information can be derived from river flow measurements and basin water budgets. The Gravity Recovery and Climate Experiment (GRACE) satellite mission provides an accurate measurement of the terrestrial gravity field variations from which land water storage variations can be derived. However, their retrieval is not straightforward, and different methods are employed, which results in different water storage GRACE products. On the other hand, water storage can be estimated by land surface modeling forced with observed or satellite-based boundary conditions, but such estimates can be highly model dependent. In this study, land water storage by six GRACE products and soil moisture estimations by nine land surface models (run within the framework of the African Monsoon Multidisciplinary Analysis Land Surface Intercomparison Project (ALMIP)) are evaluated over West Africa, with a particular focus on the Sahelian area. The water storage spatial distribution, including zonal transects, its seasonal cycle, and its and interannual variability, are analyzed for the years 2003–2007. Despite the nonnegligible differences among the various GRACE products and among the different models, a generally good agreement between satellite and model estimates is found over the West Africa study region. In particular, GRACE data are shown to reproduce well the water storage interannual variability over the Sahel for the 5 year study period. The comparison between satellite estimates and ALMIP results leads to the identification of processes needing improvement in the land surface models. In particular, our results point out the importance of correctly simulating slow water reservoirs as well as evapotranspiration during the dry season for accurate soil moisture modeling over West Africa.},
	number = {5},
	journal = {Water Resources Research},
	author = {Grippa, M. and Kergoat, L. and Frappart, F. and Araud, Q. and Boone, A. and de Rosnay, P. and Lemoine, J.-M. and Gascoin, S. and Balsamo, G. and Ottlé, C. and Decharme, B. and Saux-Picart, S. and Ramillien, G.},
	year = {2011},
	keywords = {AMMA-CATCH},
}

@article{grippa_potential_2019,
	title = {Potential of {SWOT} for {Monitoring} {Water} {Volumes} in {Sahelian} {Ponds} and {Lakes}},
	volume = {12},
	issn = {2151-1535},
	url = {https://ieeexplore.ieee.org/document/8684868/},
	doi = {10.1109/jstars.2019.2901434},
	number = {7},
	journal = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing},
	author = {Grippa, M. and Rouzies, C. and Biancamaria, S. and Blumstein, D. and Cretaux, J. F. and Gal, L. and Robert, E. and Gosset, M. and Kergoat, L.},
	month = jul,
	year = {2019},
	keywords = {AMMA-CATCH},
	pages = {2541--2549},
}

@article{hounsinou_integral_2022,
	title = {Integral turbulence characteristics over a clear woodland forest in northern {Benin} ({West} {Africa})},
	volume = {268},
	issn = {0169-8095},
	url = {https://www.sciencedirect.com/science/article/pii/S016980952100541X},
	doi = {10.1016/j.atmosres.2021.105985},
	abstract = {This study aims at investigating whether the Integral Turbulence Characteristics (ITC) obey the Monin-Obukhov Similarity Theory (MOST) above a forest site in a Sudanian climate, and at identifying the appropriate ITC models for this ecosystem. Data were collected from a 18 m tower equipped with an Eddy Covariance system, above the clear forest close to Bellefoungou's village, Northwest of Benin, West Africa. The turbulence intensity parameters calculated for five years and half, were analyzed according to wind speed, stability conditions and seasons. From their relationships with the stability parameter, data driven models were then obtained by the nonlinear least squares. The results showed that, all similarity functions follow MOST with a 1/3 power law whatever the stratification of the atmosphere during all the seasons excepted the temperature which had a parabolic shape in near neutral condition (−0.05 {\textless} ζ {\textless} 0.1). A seasonal dependence of all ITCs was evidenced under stable conditions. We also showed that the heat transfer is relatively more efficient than H2O transfer under both stability conditions. The established temperature and CO2 similarity models are found to be closer, and for some given stratification conditions, to those already existing in literature. But a noteworthy finding is that the models often used to assign a quality criterion to turbulent fluxes showed an overestimation relatively to those established ‘locally’ for u and w through all atmospheric stratification.},
	journal = {Atmospheric Research},
	author = {Hounsinou, Miriam and Mamadou, Ossénatou and Wudba, Maxime and Kounouhewa, Basile and Cohard, Jean-Martial},
	month = apr,
	year = {2022},
	keywords = {West Africa, Stability, AMMA-CATCH, LMI REZOC, Forest, Integral Turbulence Characteristics, Monin-Obukhov Similarity Theory, Similarity Functions},
	pages = {105985},
}

@article{lebel_amma_2011,
	title = {The {AMMA} field campaigns: accomplishments and lessons learned},
	volume = {12},
	issn = {1530-261X},
	url = {https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/asl.323},
	doi = {10.1002/asl.323},
	abstract = {Abstract The AMMA (African Monsoon Multidiscplinary Analysis) field programme aimed at documenting the West African Monsoon (WAM) climate system, in all its geophysical components. It also includes an important socio-economic component. Encompassing a wide range of spatial and time scales, AMMA is one of the most ambitious such programmes ever set up. While the key accomplishments of AMMA are summarised in this paper, a few lessons of broad interest are also drawn both as a tribute to the extraordinary efforts made by a community of several hundreds of people and as possible guidelines for ensuring a long lasting future to integrated climate and environmental studies in West Africa. Copyright © 2011 Royal Meteorological Society},
	number = {1},
	journal = {Atmospheric Science Letters},
	author = {Lebel, Thierry and Parker, Douglas J. and Flamant, Cyrille and Höller, Hartmut and Polcher, Jan and Redelsperger, Jean-Luc and Thorncroft, Chris and Bock, Olivier and Bourles, Bernard and Galle, Sylvie and Marticorena, Béatrice and Mougin, Eric and Peugeot, Christophe and Cappelaere, Bernard and Descroix, Luc and Diedhiou, Arona and Gaye, Amadou and Lafore, Jean-Philippe},
	month = jan,
	year = {2011},
	keywords = {AMMA-CATCH, HYBIS},
	pages = {123--128},
}

@article{ndiaye_effect_2005,
	title = {Effect of rainfall and tillage direction on the evolution of surface crusts, soil hydraulic properties and runoff generation for a sandy loam soil},
	volume = {307},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/pii/S0022169404005189},
	doi = {10.1016/j.jhydrol.2004.10.016},
	abstract = {The study was aimed at evaluating the effect of rainfall and tillage-induced soil surface characteristics on infiltration and runoff on a 2.8ha catchment located in the central region of Senegal. This was done by simulating 30min rain storms applied at a constant rate of about 70mmh−1, on 10 runoff micro-plots of 1m2, five being freshly harrowed perpendicularly to the slope and five along the slope (1\%) of the catchment. Runoff was automatically recorded at the outlet of each plot. Hydraulic properties such as capillary sorptivity and hydraulic conductivity of the sandy loam soil close to saturation were determined by running 48 infiltration tests with a tension disc infiltrometer. That allowed the calculation of a mean characteristic pore size hydraulically active and a time to ponding. Superficial water storage capacity was estimated using data collected with an electronic relief meter. Because the soil was subject to surface crusting, crust-types as well as their spatial distribution within micro-plots and their evolution with time were identified and monitored by taking photographs at different times after tillage. The results showed that the surface crust-types as well as their tillage dependent dynamics greatly explain the decrease of hydraulic conductivity and sorptivity as the cumulative rainfall since tillage increases. The exponential decaying rates were found to be significantly greater for the soil harrowed along the slope (where the runoff crust-type covers more than 60\% of the surface after 140mm of rain) than across to the slope (where crusts are mainly of structural (60\%) and erosion (40\%) types). That makes ponding time smaller and runoff more important. Also it was shown that soil hydraulic properties after about 160mm of rain were close to those of untilled plot not submitted to any rain. That indicates that the effects of tillage are short lived.},
	language = {en},
	number = {1},
	journal = {Journal of Hydrology},
	author = {Ndiaye, Babacar and Esteves, Michel and Vandervaere, Jean-Pierre and Lapetite, Jean-Marc and Vauclin, Michel},
	month = jun,
	year = {2005},
	keywords = {AMMA-CATCH, Ponding time, Rainfall simulation, Senegal, Soil crusting, Tension disc infiltrometer, Tillage direction},
	pages = {294--311},
}

@article{robert_analysis_2017,
	title = {Analysis of {Suspended} {Particulate} {Matter} and {Its} {Drivers} in {Sahelian} {Ponds} and {Lakes} by {Remote} {Sensing} ({Landsat} and {MODIS}): {Gourma} {Region}, {Mali}},
	volume = {9},
	issn = {2072-4292},
	shorttitle = {Analysis of {Suspended} {Particulate} {Matter} and {Its} {Drivers} in {Sahelian} {Ponds} and {Lakes} by {Remote} {Sensing} ({Landsat} and {MODIS})},
	url = {https://www.mdpi.com/2072-4292/9/12/1272},
	doi = {10.3390/rs9121272},
	language = {en},
	number = {12},
	journal = {Remote Sensing},
	author = {Robert, Elodie and Kergoat, Laurent and Soumaguel, Nogmana and Merlet, Sébastien and Martinez, Jean-Michel and Diawara, Mamadou and Grippa, Manuela},
	month = dec,
	year = {2017},
	keywords = {AMMA-CATCH, Mali, AO},
	pages = {1272},
}

@article{tramblay_african_2020,
	title = {The {African} {Database} of {Hydrometric} {Indices} ({ADHI})},
	volume = {2020},
	issn = {1866-3591},
	url = {https://essd.copernicus.org/preprints/essd-2020-281/ https://essd.copernicus.org/preprints/essd-2020-281/essd-2020-281.pdf},
	doi = {10.5194/essd-2020-281},
	journal = {Earth Syst. Sci. Data Discuss.},
	author = {Tramblay, Y. and Rouché, N. and Paturel, J. E. and Mahé, G. and Boyer, J. F. and Amoussou, E. and Bodian, A. and Dacosta, H. and Dakhlaoui, H. and Dezetter, A. and Hughes, D. and Hanich, L. and Peugeot, C. and Tshimanga, R. and Lachassagne, P.},
	year = {2020},
	pages = {1--21},
}

@article{marigo_spatio-temporal_2022,
	title = {Spatio-temporal {Analysis} of {Surface} and {Root} {Zone} {Soil} {Moisture} {Derived} from {SMAP} and {SMOS} {Microwave} {Satellite} {Data} {Using} in-situ {Measurements} in {Senegal}},
	volume = {10},
	issn = {2328-7241},
	url = {http://pubs.sciepub.com/env/10/1/2/index.html},
	doi = {10.12691/env-10-1-2},
	number = {1},
	urldate = {2022-06-30},
	journal = {American Journal of Environmental Protection},
	author = {Marigo, Omar and Faye, Gayane and Grippa, Manuela and Pellarin, Thierry and Mbaye, Modou and Tine, Dome and Mougin, Eric and Mbengue, Fama and Thiam, Aissata and Diop Ngom, Balla},
	month = mar,
	year = {2022},
	keywords = {AMMA-CATCH},
	pages = {8--21},
}

@article{papa_water_2022,
	title = {Water {Resources} in {Africa} under {Global} {Change}: {Monitoring} {Surface} {Waters} from {Space}},
	issn = {0169-3298, 1573-0956},
	shorttitle = {Water {Resources} in {Africa} under {Global} {Change}},
	url = {https://link.springer.com/10.1007/s10712-022-09700-9},
	doi = {10.1007/s10712-022-09700-9},
	language = {en},
	urldate = {2022-06-30},
	journal = {Surveys in Geophysics},
	author = {Papa, Fabrice and Crétaux, Jean-François and Grippa, Manuela and Robert, Elodie and Trigg, Mark and Tshimanga, Raphael M. and Kitambo, Benjamin and Paris, Adrien and Carr, Andrew and Fleischmann, Ayan Santos and de Fleury, Mathilde and Gbetkom, Paul Gerard and Calmettes, Beatriz and Calmant, Stephane},
	month = apr,
	year = {2022},
	keywords = {AMMA-CATCH},
}

@article{boubacar_moussa_spatio-temporal_2022,
	title = {Spatio-temporal dynamics of suspended particulate matter in the middle {Niger} {River} using in-situ and satellite radiometric measurements},
	volume = {41},
	issn = {22145818},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S2214581822001197},
	doi = {10.1016/j.ejrh.2022.101106},
	language = {en},
	urldate = {2022-06-30},
	journal = {Journal of Hydrology: Regional Studies},
	author = {Boubacar Moussa, Moussa and Abdourhamane Touré, Amadou and Kergoat, Laurent and Lartiges, Bruno and Rochelle-Newall, Emma and Robert, Elodie and Gosset, Marielle and Alkali Tanimoun, Bachir and Grippa, Manuela},
	month = jun,
	year = {2022},
	keywords = {AMMA-CATCH},
	pages = {101106},
}

@article{de_silans_correction_1997,
	title = {The correction of soil heat flux measurements to derive an accurate surface energy balance by the {Bowen} ratio method},
	volume = {188-189},
	issn = {00221694},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0022169496031873},
	doi = {10.1016/S0022-1694(96)03187-3},
	language = {en},
	urldate = {2020-10-22},
	journal = {Journal of Hydrology},
	author = {de Silans, Alain Passerat and Monteny, Bruno A. and Lhomme, Jean Paul},
	month = feb,
	year = {1997},
	keywords = {AMMA-CATCH, amma campaign, Hapex-Sahel},
	pages = {453--465},
}

@article{amissah-arthur_assessing_2000,
	title = {Assessing farmland dynamics and land degradation on {Sahelian} landscapes using remotely sensed and socioeconomic data},
	volume = {14},
	issn = {1365-8816, 1362-3087},
	url = {http://www.tandfonline.com/doi/abs/10.1080/136588100415756},
	doi = {10.1080/136588100415756},
	language = {en},
	number = {6},
	urldate = {2020-10-22},
	journal = {International Journal of Geographical Information Science},
	author = {Amissah-Arthur, Abigail and Mougenot, Bernard and Loireau, Maud},
	month = sep,
	year = {2000},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {583--599},
}

@article{mamadou_exorheism_2015,
	title = {Exorheism growth as an explanation of increasing flooding in the {Sahel}},
	volume = {131},
	issn = {03418162},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0341816215001009},
	doi = {10.1016/j.catena.2015.03.017},
	language = {en},
	urldate = {2020-10-22},
	journal = {CATENA},
	author = {Mamadou, Ibrahim and Gautier, Emmanuèle and Descroix, Luc and Noma, Ibrahim and Bouzou Moussa, Ibrahim and Faran Maiga, Oumarou and Genthon, Pierre and Amogu, Okechukwu and Malam Abdou, Moussa and Vandervaere, Jean-Pierre},
	month = aug,
	year = {2015},
	keywords = {AMMA-CATCH},
	pages = {130--139},
}

@article{liu_soil_2017,
	title = {Soil {Moisture} {Retrieval} and {Spatiotemporal} {Pattern} {Analysis} {Using} {Sentinel}-1 {Data} of {Dahra}, {Senegal}},
	volume = {9},
	issn = {2072-4292},
	url = {http://www.mdpi.com/2072-4292/9/11/1197},
	doi = {10.3390/rs9111197},
	language = {en},
	number = {11},
	urldate = {2019-07-05},
	journal = {Remote Sensing},
	author = {Liu, Zhiqu and Li, Pingxiang and Yang, Jie},
	month = nov,
	year = {2017},
	keywords = {AMMA-CATCH, ext1, dahra, extérieur},
	pages = {1197},
}

@article{pomeon_computationally_2018,
	title = {Computationally {Efficient} {Multivariate} {Calibration} and {Validation} of a {Grid}-{Based} {Hydrologic} {Model} in {Sparsely} {Gauged} {West} {African} {River} {Basins}},
	volume = {10},
	issn = {2073-4441},
	url = {http://www.mdpi.com/2073-4441/10/10/1418},
	doi = {10.3390/w10101418},
	abstract = {The prediction of freshwater resources remains a challenging task in West Africa, where the decline of in situ measurements has a detrimental effect on the quality of estimates. In this study, we establish a series of modeling routines for the grid-based mesoscale Hydrologic Model (mHM) using Multiscale Parameter Regionalization (MPR). We provide a computationally efficient application of mHM-MPR across a diverse range of data-scarce basins using in situ observations, remote sensing, and reanalysis inputs. Model performance was first screened for four precipitation datasets and three evapotranspiration calculation methods. Subsequently, we developed a modeling framework in which the pre-screened model is first calibrated using discharge as the observed variable (mHM Q), and next calibrated using a combination of discharge and actual evapotranspiration data (mHM Q/ET). Both model setups were validated in a multi-variable evaluation framework using discharge, actual evapotranspiration, soil moisture and total water storage data. The model performed reasonably well, with mean discharge KGE values of 0.53 (mHM Q) and 0.49 (mHM Q/ET) for the calibration; and 0.23 (mHM Q) and 0.13 (mHM Q/ET) for the validation. Other tested variables were also within a good predictive range. This further confirmed the robustness and well-represented spatial distribution of the hydrologic predictions. Using MPR, the calibrated model can then be scaled to produce outputs at much smaller resolutions. Overall, our analysis highlights the worth of utilizing additional hydrologic variables (together with discharge) for the reliable application of a distributed hydrologic model in sparsely gauged West African river basins.},
	language = {en},
	number = {10},
	urldate = {2021-07-01},
	journal = {Water},
	author = {Poméon, Thomas and Diekkrüger, Bernd and Kumar, Rohini},
	month = oct,
	year = {2018},
	keywords = {AMMA-CATCH, ext1, extérieur},
	pages = {1418},
}

@article{carvalho_resende_assessment_2019,
	title = {Assessment of the impacts of climate variability on total water storage across {Africa}: implications for groundwater resources management},
	volume = {27},
	issn = {1431-2174, 1435-0157},
	shorttitle = {Assessment of the impacts of climate variability on total water storage across {Africa}},
	url = {http://link.springer.com/10.1007/s10040-018-1864-5},
	doi = {10.1007/s10040-018-1864-5},
	language = {en},
	number = {2},
	urldate = {2020-10-22},
	journal = {Hydrogeology Journal},
	author = {Carvalho Resende, Tales and Longuevergne, Laurent and Gurdak, Jason J. and Leblanc, Marc and Favreau, Guillaume and Ansems, Nienke and Van der Gun, Jac and Gaye, Cheikh B. and Aureli, Alice},
	month = mar,
	year = {2019},
	keywords = {AMMA-CATCH, ext1},
	pages = {493--512},
}

@article{vouillamoz_contribution_2008,
	title = {Contribution of magnetic resonance sounding to aquifer characterization and recharge estimate in semiarid {Niger}},
	volume = {64},
	issn = {0926-9851},
	doi = {10.1016/j.jappgeo.2007.12.006},
	number = {3-4},
	journal = {Journal of Applied Geophysics},
	author = {Vouillamoz, J. M. and Favreau, G. and Massuel, S. and Boucher, M. and Nazoumou, Y. and Legchenko, A.},
	year = {2008},
	keywords = {AMMA-CATCH, niger},
	pages = {99--108},
}

@article{hinderer_ghyraf_2009,
	title = {The {GHYRAF} ({Gravity} and {Hydrology} in {Africa}) experiment: {Description} and first results},
	volume = {48},
	issn = {0264-3707},
	shorttitle = {The {GHYRAF} ({Gravity} and {Hydrology} in {Africa}) experiment},
	url = {http://www.sciencedirect.com/science/article/B6V9X-4XC9SG3-2/2/1e732744e3578acb74106064105aec3b},
	doi = {10.1016/j.jog.2009.09.014},
	abstract = {This paper is the first presentation of a project called GHYRAF (Gravity and Hydrology in Africa) devoted to the detailed comparison between models and multidisciplinary observations (ground and satellite gravity, geodesy, hydrology, meteorology) of the variations of water storage in Africa from the Sahara arid part to the monsoon equatorial part. We describe the various actions planned in this project. We first detail the actions planned in gravimetry which consist in two main surface gravity experiments: on the one hand the periodic repetition of absolute gravity measurements along a north-south monsoonal gradient of rainfall in West Africa, going from Tamanrasset (20 mm/year) in southern Algeria to Djougou (1200 mm/year) in central Benin; on the other hand the continuous measurements at Djougou (Benin) with a superconducting gravimeter to monitor with a higher sampling rate the gravity changes related to an extreme hydrological cycle. Another section describes the actions planned in GPS which will maintain and develop the present-day existing network in West Africa. The third type of actions deals with hydrology and we review the three sites that will be investigated in this joint hydrogeophysics project namely Wankama (near Niamey) and Bagara (near Diffa) in the Niger Sahelian zone and Nalohou (near Djougou) in the Benin monsoon zone. We also address the question of the ground truth of satellite-derived missions; in this context the GHYRAF project will lead to test the hydrology models by comparison both with in situ and satellite data such as GRACE, as well as to an important increase of our knowledge of the seasonal water cycle in Africa. We finally present preliminary results in GPS based on the analysis of the vertical motion of the Djougou site. The resulting absolute gravity changes related to the 2008 monsoon are finally given.},
	number = {3-5},
	urldate = {2010-11-12},
	journal = {Journal of Geodynamics},
	author = {Hinderer, J. and de Linage, C. and Boy, J.-P. and Gegout, P. and Masson, F. and Rogister, Y. and Amalvict, M. and Pfeffer, J. and Littel, F. and Luck, B. and Bayer, R. and Champollion, C. and Collard, P. and Le Moigne, N. and Diament, M. and Deroussi, S. and de Viron, O. and Biancale, R. and Lemoine, J.-M. and Bonvalot, S. and Gabalda, G. and Bock, O. and Genthon, P. and Boucher, M. and Favreau, G. and Séguis, L. and Delclaux, F. and Cappelaere, B. and Oi, M. and Descloitres, M. and Galle, S. and Laurent, J.-P. and Legchenko, A. and Bouin, M.-N.},
	month = dec,
	year = {2009},
	keywords = {Sahel, AMMA-CATCH, Gravity, GPS, HYBIS, Monsoon, Soudanian climate, Water storage},
	pages = {172--181},
}

@article{pellarin_soil_2009,
	title = {Soil moisture mapping over {West} {Africa} with a 30-min temporal resolution using {AMSR}-{E} observations and a satellite-based rainfall product},
	volume = {13},
	issn = {1027-5606},
	url = {http://www.hydrol-earth-syst-sci.net/13/1887/2009/},
	doi = {10.5194/hess-13-1887-2009, 2009},
	number = {10},
	urldate = {2010-11-12},
	journal = {Hydrology and Earth System Sciences},
	author = {Pellarin, T. and Tran, T. and Cohard, J.-M. and Galle, S. and Laurent, J.-P. and de Rosnay, P. and Vischel, T.},
	month = oct,
	year = {2009},
	keywords = {AMMA-CATCH, API, HYBIS, Antecedent precipitation index},
	pages = {1887--1896},
}

@article{de_condappa_bimodal_2008,
	title = {Bimodal zone of the soil textural triangle: {Common} in tropical and subtropical regions},
	volume = {72},
	issn = {1435-0661},
	shorttitle = {Bimodal {Zone} of the {Soil} {Textural} {Triangle}},
	url = {https://www.soils.org/publications/sssaj/abstracts/72/1/33},
	doi = {10.2136/sssaj2006.0343},
	number = {1},
	urldate = {2010-11-12},
	journal = {Soil Science Society of America Journal},
	author = {de Condappa, Devaraj and Galle, Sylvie and Dewandel, Benoit and Haverkamp, Randel},
	year = {2008},
	keywords = {AMMA-CATCH, benin, Inde},
	pages = {33--40},
}

@article{le_lay_exploring_2007,
	title = {Exploring the relationship between hydroclimatic stationarity and rainfall-runoff model parameter stability: {A} case study in {West} {Africa}},
	volume = {43},
	shorttitle = {Exploring the relationship between hydroclimatic stationarity and rainfall-runoff model parameter stability},
	url = {http://www.agu.org/pubs/crossref/2007/2006WR005257.shtml},
	doi = {200710.1029/2006WR005257},
	urldate = {2010-11-12},
	journal = {Water Resources Research},
	author = {Le Lay, M. and Galle, S. and Saulnier, G. M. and Braud, I.},
	month = jul,
	year = {2007},
	keywords = {AMMA-CATCH, benin},
	pages = {10 PP.},
}

@article{balme_assessing_2006,
	title = {Assessing the water balance in the {Sahel}: {Impact} of small scale rainfall variability on runoff: {Part} 1: {Rainfall} variability analysis},
	volume = {331},
	issn = {0022-1694},
	shorttitle = {Assessing the water balance in the {Sahel}},
	url = {http://www.sciencedirect.com/science/article/B6V6C-4KPFKXP-1/2/d810e56c02aacce8e89e0ae7f692d7de},
	doi = {10.1016/j.jhydrol.2006.05.020},
	abstract = {Summary The mesoscale variability of the Sahelian rainfall is analysed from a series of 30 high time resolution rainfall series covering 13 years and a 110 × 160 km2 area in the region of Niamey. It is shown that the convective scale variability is strongly influencing the spatial pattern of rainfields at larger time and spatial scales. This means that a proper assessment of the rainfall patterns at the mesoscale in the Sahel requires raingauge networks with a sufficient density to allow sampling this convective scale variability. This is usually not the case with operational networks whose density is in the order of 1-2 gauges per 10,000 km2. Computations carried out here show that the areal rainfall estimation error increases from 3\% to 16\% at the annual scale and from 21\% to 113\% at the event scale when the number of stations over a 100 × 100 km2 area decreases from 12 to 1. While being highly variable in space, the Sahelian rainfall is also highly intermittent in time. An analysis of the series of tipping bucket times leads to compute that 50\% of the annual rain falls in less than 4 h with intensities larger than 35 mm/h. Areal rainfall statistics are compared to point rainfall statistics for event accumulated rainfall. The implication of these results for studying the influence of rainfall intermittency on runoff is discussed in a final section, as an introduction to a companion paper.},
	number = {1-2},
	urldate = {2010-11-12},
	journal = {Journal of Hydrology},
	author = {Balme, Maud and Vischel, Théo and Lebel, Thierry and Peugeot, Christophe and Galle, Sylvie},
	month = nov,
	year = {2006},
	keywords = {Sahel, Intermittency, AMMA-CATCH, Rainfall variability, AO, Areal rainfall, Rainfall estimation error, Rainfall intensities},
	pages = {336--348},
}

@article{varado_multi-criteria_2006,
	title = {Multi-criteria assessment of the {Representative} {Elementary} {Watershed} approach on the {Donga} catchment ({Benin}) using a downward approach of model complexity},
	volume = {10},
	issn = {1027-5606},
	url = {http://www.hydrol-earth-syst-sci.net/10/427/2006/},
	doi = {10.5194/hess-10-427-2006},
	number = {3},
	urldate = {2010-11-12},
	journal = {Hydrology and Earth System Sciences},
	author = {Varado, N. and Braud, I. and Galle, S. and Le Lay, M. and Séguis, L. and Kamagate, B. and Depraetere, C.},
	month = jun,
	year = {2006},
	keywords = {AMMA-CATCH, benin},
	pages = {427--442},
}

@article{le_lay_variabilites_2005,
	title = {Variabilités interannuelle et intra-saisonnière des pluies aux échelles hydrologiques. {La} mousson ouest-africaine en climat soudanien / {Seasonal} cycle and interannual variability of rainfall at hydrological scales. {The} {West} {African} monsoon in a {Sudanese} climate},
	volume = {50},
	issn = {0262-6667},
	url = {http://www.informaworld.com/10.1623/hysj.50.3.509.65029},
	doi = {10.1623/hysj.50.3.509.65029},
	number = {3},
	urldate = {2010-11-12},
	journal = {Hydrological Sciences Journal},
	author = {Le Lay, Matthieu and Galle, Sylvie},
	year = {2005},
	keywords = {AMMA-CATCH},
	pages = {509--524},
}

@article{braud_use_2005,
	title = {Use of scaled forms of the infiltration equation for the estimation of unsaturated soil hydraulic properties (the {Beerkan} method)},
	volume = {56},
	issn = {1351-0754},
	url = {http://apps.isiknowledge.com/full_record.do?product=WOS&search_mode=GeneralSearch&qid=6&SID=R12FlHHGiGDOLmooj56&page=2&doc=18},
	doi = {10.1111/j.1365-2389.2004.00660.x},
	abstract = {Water movement in soil can be described accurately at the local scale, provided that soil hydraulic properties can be determined with precision. Traditional methods for characterizing soil are often time consuming, and large areas cannot be sampled easily. We present a simple method for overcoming these difficulties. It is easy to implement and cheap. It is known as the Beerkan method, and it relies on particle-size analysis, dry bulk density and simple infiltration tests in cylinders. We describe the experimental protocol and the method of data analysis, leading to the estimation of parameters describing hydraulic properties. Shape parameters depend on soil texture and are derived from particle-size data. Normalization parameters depend on soil structure. They are derived by inverse modelling and optimization from the infiltration tests. The theoretical background relies on the sorptivity concept and scaled forms of the infiltration equation. The formalism for one- and three-dimensional analysis is described. We assess the accuracy of the method using published data and simulated values, showing the soundness of the approach. For the purpose of illustration, we implemented a simple optimization technique on two bounding cases.},
	number = {3},
	urldate = {2010-11-12},
	journal = {European Journal of Soil Science},
	author = {Braud, I and De Condappa, D and Soria, JM and Haverkamp, R and Angulo-Jaramillo, R and Galle, S. and Vauclin, M},
	month = jun,
	year = {2005},
	keywords = {AMMA-CATCH},
	pages = {361--374},
}

@article{seghieri_relationships_1997,
	title = {Relationships between soil moisture and growth of herbaceous plants in a natural vegetation mosaic in {Niger}},
	volume = {36},
	issn = {0140-1963},
	url = {http://www.sciencedirect.com/science/article/B6WH9-45MH2GY-7/2/f6cee1dca0818f63bf9af8bbf0b563cc},
	doi = {10.1006/jare.1996.0195},
	abstract = {The [`]tiger bush' is a particular vegetation pattern in which densely vegetated bands alternate with bare areas. In general, bare areas are working as impluvium for the downslope vegetated stripes. The intraseasonal regimes of soil moisture are quantified during a rainy season, and their influence on the growth of the annual vegetation is analysed. Data were collected along the line of maximum slope crossing two vegetated bands. Density and phenology of herbaceous layer are related to the changes of soil moisture and to the associated soil surface features. The herbaceous layer comprises only annual species, mainly composed of the tiny grassMicrochloa indicaandCyanotis lanata(Commelinaceae). Both are indicators of long-term overgrazing. The distribution ofMicrochloa indicais well correlated with the sedimentary crusts located immediately upslope of the thicket.Cyanotis lanatais the only species recorded in the downslope part of the transect. Its distribution is well correlated with the biological crusts located in the core of the thicket, where infiltration first occurs and high infiltration rates are seen, as long as shade and litter are not limiting for seedling development. As the rainy season progresses, infiltration also increases upslope of the thicket which, until then, remains bare and where onlyMicrochloa indicagerminates provided the seed stock is not limiting.},
	number = {1},
	urldate = {2010-11-12},
	journal = {Journal of Arid Environments},
	author = {Seghieri, J. and Galle, S. and Rajot, J. L. and Ehrmann, M.},
	month = may,
	year = {1997},
	keywords = {Sahel, soil moisture, AMMA-CATCH, Niger, annual grasses, dynamics, patterned vegetation},
	pages = {87--102},
}

@article{esteves_overland_2000,
	title = {Overland flow and infiltration modelling for small plots during unsteady rain: numerical results versus observed values},
	volume = {228},
	issn = {0022-1694},
	shorttitle = {Overland flow and infiltration modelling for small plots during unsteady rain},
	url = {http://www.sciencedirect.com/science/article/B6V6C-401HGV9-M/2/791d8a49a07951809d59d5ec31bdf938},
	doi = {10.1016/S0022-1694(00)00155-4},
	abstract = {This paper reports the development and application of a two-dimensional model based on an explicit finite difference scheme coupling overland flow and infiltration processes for natural hillslopes represented by topographic elevation and soil hydraulics parameters. This model allows modelling of hortonian overland flow and infiltration during complex rainfall events. Original procedures have been developed in order to simulate complex rainfall events on natural slopes. The accuracy of the results is tested by comparison with experimental field data on the basis of calibrated soil and surface friction parameters. Good agreement between the calculated result and the measured data was found. The scheme proposed was found to be appropriate. The results of tests presented illustrate the effect of microtopography on the distribution of the flow depths, the magnitude and direction of flow velocities and infiltration depths.},
	number = {3-4},
	urldate = {2010-11-12},
	journal = {Journal of Hydrology},
	author = {Esteves, M. and Faucher, X. and Galle, S. and Vauclin, M.},
	month = mar,
	year = {2000},
	keywords = {Overland flow, AMMA-CATCH, Green-Ampt equation, Microrelief, Runoff generation, Two-dimensional modelling},
	pages = {265--282},
}

@article{rockstrom_-farm_1999,
	title = {On-{Farm} {Spatial} and {Temporal} {Variability} of {Soil} and {Water} in {Pearl} {Millet} {Cultivation}},
	volume = {63},
	url = {https://www.soils.org/publications/sssaj/abstracts/63/5/1308},
	doi = {10.2136/sssaj1999.6351308x},
	abstract = {Crust-prone sandy soils of low fertility, combined with unreliable and erratic rainfall, affect spatial variability of crop growth in the Sahel. We hypothesized that spatial variability in soil properties and soil water content on a hillslope scale affected pearl millet [Pennisetum glaucum (L.) Br.] yields. We focused on the effects of crust development, micro topography, rill distribution, and soil nutrients on crop yield variability within and between years (1994–1996) in a farmer's field in semi-arid Niger. Yields in plots of 15 by 6 m varied within a year by a factor of 46 for nonfertilized millet (27–1249 kg ha−1), and by a factor of 16 (76–1213 kg ha−1) for fertilized millet. Despite this variation, a linear yield gradient was observed along the 300-m-long field with a gentle 1 to 3\% slope. Grain yields decreased 0.5 kg ha−1 for nonfertilized millet and 1 kg ha−1 for fertilized millet per meter along the slope when moving from the bottom to the top of the field. Soil water availability varied greatly, with individual neutron probe access tubes (36 tubes on an 8-ha field) presenting a percent infiltration ranging from 15 to 182\% of rainfall for individual rainstorms. Upslope had significantly lower percent infiltration (75\%) than both midslope (90\%) and downslope (84\%). Between years, soil water and nutrients alternated in limiting crop growth, depending on rainfall distribution (annual rainfall ranging from 488–596 mm). However, in all three years toposequence related factors dominated yield variability and caused similar yield gradients along the slope.},
	number = {5},
	urldate = {2010-11-12},
	journal = {Soil Science Society of America Journal},
	author = {Rockström, J. and Barron, J. and Brouwer, J. and Galle, S. and de Rouw, A.},
	year = {1999},
	keywords = {AMMA-CATCH},
	pages = {1308--1319},
}

@article{seghieri_run-contribution_1999,
	title = {Run-on contribution to a {Sahelian} two-phase mosaic system: {Soil} water regime and vegetation life cycles},
	volume = {20},
	issn = {1146-609X},
	shorttitle = {Run-on contribution to a {Sahelian} two-phase mosaic system},
	url = {http://www.sciencedirect.com/science/article/B6VR3-3XK7GF7-8/2/60704e80b4db1a240483371e9ce2cbe6},
	doi = {10.1016/S1146-609X(99)80033-2},
	abstract = {An experiment was carried out from 1992 to 1995, in south-western Niger on a banded vegetation pattern which dominates on a laterite-capped plateau in the region. We quantified the changes in infiltration and vegetation in a thicket from which run-on from the upslope bare soil zone was artificially divested. A concrete wall (40 m long, 60 cm high, 20 cm thick, with a foundation 25 cm deep) was constructed at its upslope boundary. Infiltration was measured to a depth of 5.4 m by a neutron probe, and densities of annual plants were monitored along transects crossing perpendicularly a control thicket and the thicket deprived of run-on. Phenological phases and leaf water potential of the two dominant shrub species were recorded from stratified sampling according to their preferred location along the water resource gradient. Results indicated that run-on contributed the most to infiltration in the central zone, but the water content available to the annual plants (layer 0-10 cm) was not affected by run-on deprivation. Significant differences were found in the water content available to the shrubs (layer 0-100 cm) both between zones (upslope and central), and between thickets after the wall was built. However, in the thicket deprived of run-on, life cycle and physiology of the shrubs were severely disturbed upslope, while much smaller effects were observed in the centre. Surprisingly, within thestudy interval, run-on contribution was not found to be as essential to shrubs' life cycle at the location where it contributed the most to the infiltration.},
	number = {3},
	urldate = {2010-11-12},
	journal = {Acta Oecologica},
	author = {Seghieri, Josiane and Galle, Sylvie},
	month = may,
	year = {1999},
	keywords = {AMMA-CATCH, Banded vegetation pattern, gradient, leaf water potential, life history strategy, phenology, water flow, water resource},
	pages = {209--217},
}

@article{galle_water_1999,
	title = {Water balance in a banded vegetation pattern: {A} case study of tiger bush in western {Niger}},
	volume = {37},
	issn = {0341-8162},
	shorttitle = {Water balance in a banded vegetation pattern},
	url = {http://www.sciencedirect.com/science/article/B6VCG-3X10S8X-D/2/265f7be0e56349bd8751c6b9a2f25d25},
	doi = {10.1016/S0341-8162(98)90060-1},
	abstract = {The tiger bush is a patterned woodland with alternating bare area and vegetated stripes. In Niger, it covers one third of the Sahelian zone. These natural forests are of considerable economical interest since they are the main source of livestock forage and domestic energy. Its sustainable exploitation needs improved understanding of its dynamics. The redistribution of water between thicket and intervening bare areas is decisive for the water supply of the vegetation. Tiger bush patterning replicates an elementary unit composed of a bare area, the upslope border, the core and the downslope margin of the thicket. (Each zone of tiger bush is characterised by specific soil crusting associated with vegetation). Both water storage and runoff have been monitored after each rain, over a period of 4 yr, including contrasting rainy seasons, on the different zones composing the tiger bush. On the three crusted zones, runoff has a piecewise linear relationship with rain: on closed plots, runoff yield vs. annual rainfall ratio reaches 54\% on bare soil, 2\% on upslope border and 18\% on downslope border. The measured infiltration confirms these rates on independent plots. In the core of the thicket, measured infiltration corresponds with the sum of the contributions of upslope zones, weighted by their relative lengths. This model predicts that bare area contributes up to 62\% of the thicket supply, while direct rain is 27\%, the senescence zone is 10\% and the upslope border contribution is negligible (1\%). The average water infiltration in the thicket is equal to 4× the incident rainfall, but water redistribution is not homogeneous within the core of the thicket. By the most favourable location, infiltration depth is measured to be about 8× the rainfall. The important runoff, mainly generated on the impervious bare area crosses the upslope border of the thicket without infiltrating, and entirely benefit to the core. Nothing is left to the downslope border, only rainfed. The upslope border, often described as favourable location for young plants is only rainfed most part of the year. By the end of the season, its increasing porosity, due to vegetation and termite activity let it benefit of the last rains. The simple water balance model based on runoff measurement is satisfactorily validated by independent observed infiltration.},
	number = {1-2},
	urldate = {2010-11-12},
	journal = {Catena},
	author = {Galle, S. and Ehrmann, M. and Peugeot, C.},
	month = sep,
	year = {1999},
	keywords = {Sahel, Water balance, AMMA-CATCH, Runoff yield, Soil moisture storage, Tiger bush},
	pages = {197--216},
}

@article{peugeot_runoff_1997,
	title = {Runoff generation processes: results and analysis of field data collected at the {East} {Central} {Supersite} of the {HAPEX}-{Sahel} experiment},
	volume = {188-189},
	issn = {0022-1694},
	shorttitle = {Runoff generation processes},
	url = {http://www.sciencedirect.com/science/article/B6V6C-4D03X01-B/2/9fe02cf0ba7f2106d4354f555b31aacb},
	doi = {10.1016/S0022-1694(96)03159-9},
	abstract = {Within the scope of the HAPEX-Sahel experiment, the hydrological functioning of two small nested catchments was studied at two different scales: the plot scale (of the order of 100 m2) and the catchment scale (0.2 km2). At local scale, four runoff plots were set-up on the typical soil surface conditions observed on the catchments (plateau bare soil, two plots on fallow grassland) and an additional one was installed on a millet field. soil moisture investigations at the plot scale have shown that infiltration was limited between 0.6 to 2 m deep on three sites, but was deeper than 3.4 m on the most pervious site (millet). The maximum water storage on all the sites was found to be reached at the maximum activity of the rainy season (late August), and not at the end of the season. During the dry months, the soil was fully dried off by evapotranspiration, resulting in the absence of inter-annual soil water storage. No influence of vegetation cover on runoff was observed on the fallow sites, but runoff generation was found to be very sensitive to tillage on the millet field. The parameter Pu, calculated from a rainfall hyetograph and defined as the rainfall depth that can actually produce runoff, is shown to be relevant to compute runoff on untilled soils, as it explains more than 87\% of the variance in runoff depth. On tilled soils, it is necessary to take into account additionally the temporal evolution of the soil surface, especially the days after weeding operations. Simple linear relationships were derived to compute runoff depth from Pu on the plots for the most typical soil moisture conditions observed, and modified SCS equations have been derived for the catchments. Using the linear equations derived at the plot scale in a simple, empirical, semi-distributed model lead to formulate the assumption that the partial source area concept applied on the catchments. Analysis of discharge data at the catchment scale highlights that seepage through the bottom of a gully between two gauging stations leads to the abstraction of non negligible volumes of water. Moreover, the water totally infiltrates in a spreading zone downstream from the outlet of the largest catchment showing that discontinuities occur in the surface water transmission within a catena. Such discontinuities constitute a major problem for the concern of aggregation of hydrologic processes.},
	urldate = {2010-11-12},
	journal = {Journal of Hydrology},
	author = {Peugeot, C. and Esteves, M. and Galle, S. and Rajot, J.L. and Vandervaere, J.P.},
	month = feb,
	year = {1997},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {179--202},
}

@article{monteny_role_1997,
	title = {The role of the {Sahelian} biosphere on the water and the {CO2} cycle during the {HAPEX}-{Sahel} experiment},
	volume = {188-189},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/B6V6C-4D03X01-X/2/2a7d7717c87859cf41ea1b023b790a75},
	doi = {10.1016/S0022-1694(96)03191-5},
	abstract = {The HAPEX-Sahel experiment was organized to investigate the impact of water, energy and CO2 fluxes at the soil-vegetation-atmosphere interface on climate processes in the Sahelian region. Measurements of the energy balance components, CO2 flux and soil moisture were conducted over a savanna area at the East Central Supersite of the one degree square during a 3 month period in 1992. The aim of this particular investigation was to understand the role of surface conditions (i.e. vegetation and moisture) in the partitioning of available energy at the surface into sensible and latent heat flux. It also aimed to improve the understanding of how water and carbon cycles are affected by vegetation functioning, soil water availability and atmospheric demand. The analysis presented in this paper showed that the relative contribution of the soil and the vegetation to latent heat flux varies intimately with the temporal rainfall distribution and the growth of the savanna grass species, which is more sensitive to the distribution of precipitation than to its amount. Finally, semi-empirical parameterizations were developed to formulate (1) the daily evapotranspiration rate of the savanna in terms of available energy at the surface and soil water content, and (2) the instantaneous carbon uptake in terms of photosynthetically active radiation received at the surface and soil water availability.},
	urldate = {2010-11-12},
	journal = {Journal of Hydrology},
	author = {Monteny, B.A. and Lhomme, J.P. and Chehbouni, A. and Troufleau, D. and Amadou, M. and Sicot, M. and Verhoef, A. and Galle, S. and Said, F. and Lloyd, C.R.},
	month = feb,
	year = {1997},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {516--535},
}

@article{nicholson_daily_1997,
	title = {A daily resolution evapoclimatonomy model applied to surface water balance calculations at the {HAPEX}-{Sahel} supersites},
	volume = {188-189},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/B6V6C-4D03X01-1K/2/37617410ed1e27672190238702529d0f},
	doi = {10.1016/S0022-1694(96)03178-2},
	abstract = {This paper describes the results of Lettau's evapoclimatonomy model at daily time scales as applied to the Central East and Southern supersites of the HAPEX-Sahel region in Niger, West Africa. A revised version of the evapoclimatonomy model has been applied to the millet and bush fallow (Guiera senegalensis) fields at both supersites during the intensive observation period (IOP; 20 August-12 October, 1992), using daily means of precipitation, potential evapotranspiration, solar radiation, normalized difference vegetation index (NDVI) from the HAPEX-Sahel observations, as well as vegetation and soil parameters for the region. Soil moisture and immediate and delayed evapotranspiration and runoff are predicted. It has been found that the model predicts the soil moisture at the Central Eastern supersite quite well. However, it overestimates soil moisture at the Southern supersite even though its variability is captured by the model. Model results also indicate that soil moisture estimates are very sensitive to the NDVI-evaporivity relationship, which is robust at monthly scales but needs more revision for application at the daily scale. Overall the model performance when applied to the IOP observations is sufficiently good to indicate the suitability of the climatonomy for water balance studies on daily time scales.},
	urldate = {2010-11-12},
	journal = {Journal of Hydrology},
	author = {Nicholson, Sharon E. and Marengo, JoséA. and Kim, Jeeyoung and Lare, Andrew R. and Galle, Sylvie and Kerr, Yann H.},
	month = feb,
	year = {1997},
	keywords = {AMMA-CATCH, Niger, Hapex-Sahel},
	pages = {946--964},
}

@article{cuenca_soil_1997,
	title = {Soil measurements during {HAPEX}-{Sahel} intensive observation period},
	volume = {188-189},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/B6V6C-4D03X01-D/2/cbd7dab751d9be77b438f86fa4fc58fe},
	doi = {10.1016/S0022-1694(96)03161-7},
	abstract = {This article describes measurements made at each site and for each vegetation cover as part of the soils program for the HAPEX-Sahel regional scale experiment. The measurements were based on an initial sampling scheme and included profile soil water content, surface soil water content, soil water potential, infiltration rates, additional measurements on core samples, and grain size analysis. The measurements were used to categorize the state of the surface and profile soil water regimes during the experiment and to derive functional relationships for the soil water characteristic curve, unsaturated hydraulic conductivity function, and infiltration function. Sample results for different supersites and different vegetation covers are presented showing soil water profiles and total soil water storage on days corresponding to the experimental [`]Golden Days'. Sample results are also presented for spatial and temporal distribution of surface moisture content and infiltration tests. The results demonstrate that the major experimental objective of monitoring the supersites during the most rapid vegetative growth stage with the largest change of the surface energy balance following the rainy season was very nearly achieved. Separation of the effects of probable root activity and drainage of the soil profile is possible. The potential for localized advection between the bare soil and vegetation strips of the tiger bush sites is demonstrated.},
	urldate = {2010-11-12},
	journal = {Journal of Hydrology},
	author = {Cuenca, R.H. and Brouwer, J. and Chanzy, A. and Droogers, P. and Galle, S. and Gaze, S.R. and Sicot, M. and Stricker, H. and Angulo-Jaramillo, R. and Boyle, S.A. and Bromley, J. and Chebhouni, A.G. and Cooper, J.D. and Dixon, A.J. and Fies, J.-C. and Gandah, M. and Gaudu, J.-C. and Laguerre, L. and Lecocq, J. and Soet, M. and Steward, H.J. and Vandervaere, J.-P. and Vauclin, M.},
	month = feb,
	year = {1997},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {224--266},
}

@article{marengo_application_1996,
	title = {Application of {Evapoclimatonomy} to {Monthly} {Surface} {Water} {Balance} {Calculations} at the {HAPEX}-{Sahel} {Supersites}},
	volume = {35},
	issn = {0894-8763},
	url = {http://journals.ametsoc.org/doi/abs/10.1175/1520-0450%281996%29035%3C0562%3AAOETMS%3E2.0.CO%3B2},
	doi = {10.1175/1520-0450(1996)035<0562:AOETMS>2.0.CO;2},
	number = {4},
	urldate = {2010-11-12},
	journal = {Journal of Applied Meteorology},
	author = {Marengo, JoséA. and Nicholson, Sharon E. and Lare, Andrew R. and Monteny, Bruno A. and Galle, Sylvie},
	month = apr,
	year = {1996},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {562--573},
}

@article{boke-olen_estimating_2016,
	title = {Estimating and {Analyzing} {Savannah} {Phenology} with a {Lagged} {Time} {Series} {Model}},
	volume = {11},
	issn = {1932-6203},
	url = {http://dx.plos.org/10.1371/journal.pone.0154615},
	doi = {10.1371/journal.pone.0154615},
	language = {en},
	number = {4},
	urldate = {2016-05-12},
	journal = {PLOS ONE},
	author = {Boke-Olén, Niklas and Lehsten, Veiko and Ardö, Jonas and Beringer, Jason and Eklundh, Lars and Holst, Thomas and Veenendaal, Elmar and Tagesson, Torbern},
	editor = {Tanase, Mihai A.},
	month = apr,
	year = {2016},
	keywords = {AMMA-CATCH, ext1, Senegal, extérieur},
	pages = {e0154615},
}

@article{ago_response_2016,
	title = {Response of {CO2} fluxes and productivity to water availability in two contrasting ecosystems in northern {Benin} ({West} {Africa})},
	volume = {73},
	issn = {1297-966X},
	url = {http://dx.doi.org/10.1007/s13595-016-0542-9},
	doi = {10.1007/s13595-016-0542-9},
	abstract = {CO 2 fluxes were measured during 18 months in a forest and a savannah in northern Benin. Higher values of carbon fluxes were found during the wet season at each site. A strong dependency of carbon fluxes on water relations was found in two contrasting sites. The forest sequestered 640 ± 50 and the savannah 190 ± 40 g C m −2 year −1 .},
	number = {1},
	journal = {Annals of Forest Science},
	author = {Ago, Expedit Evariste and Agbossou, Euloge Kossi and Cohard, Jean-Martial and Galle, Sylvie and Aubinet, Marc},
	year = {2016},
	keywords = {AMMA-CATCH, benin, Bellefoungou, Nalohou, PHYREV},
	pages = {483--500},
}

@article{descroix_evaluation_2002,
	title = {Evaluation of an antecedent precipitation index to model runoff yield in the western {Sierra} {Madre} ({North}-west {Mexico})},
	volume = {263},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/B6V6C-45KNBFT-1/2/2c1ee9fbc7c8190d99d4608143b74461},
	doi = {10.1016/S0022-1694(02)00047-1},
	abstract = {In a subtropical mountain of northern Mexico, soils and slopes seem to have a hortonian functioning, as it is commonly observed in other tropical or subtropical areas. So it is important to know previous soil moisture before any rainfall event in order to properly estimate the runoff coefficients and to get a better understanding of the hydrologic behaviour of the catchments. A very simple deterministic model, named NAZASM, is developed and tested for 6 microplots (1 and 10 m2), 13 plots (50 m2) and 5 catchments (1-50 km2). It is based on the [`]antecedent precipitation index' with an exponential decay parameter ([alpha]) into the rainfall-runoff relationship. Measurements of rainfall and runoff were made during four rainy seasons. Between 22 and 157 rain events were considered in the analysis, depending on the sizes of the plots and catchments. [`]NAZASM' gives reasonable estimations of runoff if the calibration data set includes events occurring during wet and dry years, due to the difference of hydrological processes involved in these two situations. All the results have shown that the use of such a model significantly improves the explained variances between measured runoff and rainfall as compared to classical regression analysis, whatever the size of plots and catchments are. The [alpha] soil water content decay parameter which in theory is a soil characteristic, appeared in fact to be scale dependent.},
	number = {1-4},
	urldate = {2010-12-03},
	journal = {Journal of Hydrology},
	author = {Descroix, L. and Nouvelot, J. -F. and Vauclin, M.},
	month = jun,
	year = {2002},
	keywords = {Hortonian runoff, AMMA-CATCH, API, Antecedent precipitation index, Deterministic model, Rainfall-runoff relationship, Western Sierra Madre},
	pages = {114--130},
}

@article{sultan_west_2003,
	title = {The {West} {African} monsoon dynamics. {Part} {I}: {Documentation} of intraseasonal variability},
	volume = {16},
	issn = {1520-0442},
	shorttitle = {The {West} {African} monsoon dynamics. {Part} {I}},
	doi = {10.1175/1520-0442(2003)016<3389:TWAMDP>2.0.CO;2},
	number = {21},
	journal = {Journal of Climate},
	author = {Sultan, B. and Janicot, S. and Diedhiou, A.},
	year = {2003},
	keywords = {AMMA-CATCH},
	pages = {3389--3406},
}

@article{sankaran_determinants_2005,
	title = {Determinants of woody cover in {African} savannas},
	volume = {438},
	issn = {0028-0836, 1476-4679},
	url = {http://www.nature.com/doifinder/10.1038/nature04070},
	doi = {10.1038/nature04070},
	number = {7069},
	urldate = {2015-11-25},
	journal = {Nature},
	author = {Sankaran, Mahesh and Hanan, Niall P. and Scholes, Robert J. and Ratnam, Jayashree and Augustine, David J. and Cade, Brian S. and Gignoux, Jacques and Higgins, Steven I. and Le Roux, Xavier and Ludwig, Fulco and Ardo, Jonas and Banyikwa, Feetham and Bronn, Andries and Bucini, Gabriela and Caylor, Kelly K. and Coughenour, Michael B. and Diouf, Alioune and Ekaya, Wellington and Feral, Christie J. and February, Edmund C. and Frost, Peter G. H. and Hiernaux, Pierre and Hrabar, Halszka and Metzger, Kristine L. and Prins, Herbert H. T. and Ringrose, Susan and Sea, William and Tews, Jörg and Worden, Jeff and Zambatis, Nick},
	month = dec,
	year = {2005},
	keywords = {AMMA-CATCH},
	pages = {846--849},
}

@article{dorgeval_sensitivity_2008,
	title = {Sensitivity of the {West} {African} hydrological cycle in {ORCHIDEE} to infiltration processes},
	volume = {12},
	issn = {1027-5606},
	url = {http://www.hydrol-earth-syst-sci.net/12/1387/2008/},
	doi = {10.5194/hess-12-1387-2008},
	number = {6},
	urldate = {2010-12-03},
	journal = {Hydrology and Earth System Sciences},
	author = {d'Orgeval, T. and Polcher, J. and de Rosnay, P.},
	month = dec,
	year = {2008},
	keywords = {AMMA, AMMA-CATCH, niger},
	pages = {1387--1401},
}

@article{mougin_amma-catch_2009,
	title = {The {AMMA}-{CATCH} {Gourma} observatory site in {Mali}: {Relating} climatic variations to changes in vegetation, surface hydrology, fluxes and natural resources},
	volume = {375},
	issn = {0022-1694},
	shorttitle = {The {AMMA}-{CATCH} {Gourma} observatory site in {Mali}},
	url = {http://apps.isiknowledge.com/full_record.do?product=WOS&search_mode=GeneralSearch&qid=1&SID=Y1a3kLPaIOHdJpjgG2K&page=1&doc=3},
	doi = {10.1016/j.jhydrol.2009.06.045},
	abstract = {The Gourma site in Mali is one of the three instrumented meso-scale sites deployed in West-Africa as part of the African Monsoon Multi-disciplinary Analysis (AMMA) project. Located both in the Sahelian zone sensu stricto, and in the Saharo-Sahelian transition zone, the Gourma meso-scale window is the northernmost site of the AMMA-CATCH observatory reached by the West African Monsoon. The experimental strategy includes deployment of a variety of instruments, from local to meso-scale, dedicated to monitoring and documentation of the major variables characterizing the climate forcing, and the spatio-temporal variability of surface processes and state variables such as vegetation mass, leaf area index (LAI), soil moisture and surface fluxes. This paper describes the Gourma site, its associated instrumental network and the research activities that have been carried out since 1984. In the AMMA project, emphasis is put on the relations between climate, vegetation and surface fluxes. However, the Gourma site is also important for development and validation of satellite products, mainly due to the existence of large and relatively homogeneous surfaces. The social dimension of the water resource uses and governance is also briefly analyzed, relying on field enquiry and interviews. The climate of the Gourma region is semi-arid, daytime air temperatures are always high and annual rainfall amounts exhibit strong inter-annual and seasonal variations. Measurements sites organized along a north-south transect reveal sharp gradients in surface albedo, net radiation, vegetation production, and distribution of plant functional types. However, at any point along the gradient, surface energy budget, soil moisture and vegetation growth contrast between two main types of soil surfaces and hydrologic systems. On the one hand, sandy soils with high water infiltration rates and limited run-off support almost continuous herbaceous vegetation with scattered woody plants. On the other hand, water infiltration is poor on shallow soils, and vegetation is sparse and discontinuous, with more concentrated run-off that ends in pools or low lands within structured endorheic watersheds. Land surface in the Gourma is characterized by rapid response to climate variability, strong intra-seasonal, seasonal and inter-annual variations in vegetation growth, soil moisture and energy balance. Despite the multi-decadal drought, which still persists, ponds and lakes have increased, the grass cover has largely recovered, and there are signs of increased tree cover at least in the low lands. (C) 2009 Elsevier B.V. All rights reserved.},
	number = {1-2},
	urldate = {2011-04-08},
	journal = {Journal of Hydrology},
	author = {Mougin, E. and Hiernaux, P. and Kergoat, L. and Grippa, M. and de Rosnay, P. and Timouk, F. and Le Dantec, V. and Demarez, V. and Lavenu, F. and Arjounin, M. and Lebel, T. and Soumaguel, N. and Ceschia, E. and Mougenot, B. and Baup, F. and Frappart, F. and Frison, PL. and Gardelle, J. and Gruhier, C. and Jarlan, L. and Mangiarotti, S. and Sanou, B. and Tracol, Y. and Guichard, F. and Trichon, V. and Diarra, L. and Soumare, A. and Koite, M. and Dembele, F. and Lloyd, C. and Hanan, NP. and Damesin, C. and Delon, C. and Serca, D. and Galy-Lacaux, C. and Seghieri, J. and Becerra, S. and Dia, H. and Gangneron, F. and Mazzega, P.},
	month = aug,
	year = {2009},
	keywords = {AMMA, Sahel, rainfall, AMMA-CATCH, Mali, HYBIS, desertification, dynamics model, Gourma, ndvi data, products, reinterpretation, sahara, satellite data, Vegetation, west-africa, wind scatterometer data},
	pages = {14--33},
}

@article{pellarin_using_2008,
	title = {Using spaceborne surface soil moisture to constrain satellite precipitation estimates over {West} {Africa}},
	volume = {35},
	issn = {0094-8276},
	url = {http://apps.isiknowledge.com/full_record.do?product=UA&search_mode=GeneralSearch&qid=113&SID=S22@9lK8GI7ec9l2FAa&page=1&doc=1&colname=WOS},
	doi = {10.1029/2007GL032243},
	number = {2},
	urldate = {2010-12-03},
	journal = {Geophysical Research Letters},
	author = {Pellarin, Thierry and Ali, Abdou and Chopin, Franck and Jobard, Isabelle and Bergès, Jean-Claude},
	month = jan,
	year = {2008},
	keywords = {AMMA, AMMA-CATCH, niger, ao, benin, mali},
}

@article{moumouni_main_2008,
	title = {Main features of rain drop size distributions observed in {Benin}, {West} {Africa}, with optical disdrometers},
	volume = {35},
	issn = {0094-8276},
	url = {http://apps.isiknowledge.com/full_record.do?product=UA&search_mode=GeneralSearch&qid=126&SID=S22@9lK8GI7ec9l2FAa&page=1&doc=2&colname=WOS},
	doi = {10.1029/2008GL035755},
	number = {23},
	urldate = {2010-12-03},
	journal = {Geophysical Research Letters},
	author = {Moumouni, Sounmaila and Gosset, Marielle and Houngninou, Etienne},
	month = dec,
	year = {2008},
	keywords = {AMMA-CATCH, benin},
}

@article{leblanc_land_2008,
	title = {Land clearance and hydrological change in the {Sahel}: {SW} {Niger}},
	volume = {61},
	issn = {0921-8181},
	shorttitle = {Land clearance and hydrological change in the {Sahel}},
	url = {http://www.sciencedirect.com/science/article/B6VF0-4PRYG2S-1/2/7d64f494d71bb2a88bb20512162106d1},
	doi = {10.1016/j.gloplacha.2007.08.011},
	abstract = {In the West African semiarid belt of the Sahel, for the second half of the XXth century, lasting droughts (1970s-1980s) and one of the World's highest population growths have resulted in major land cover and hydrological changes that can be quantified using aerial photographs. This paper aims to provide one of the longest combined observations of land cover and hydrological changes for semiarid areas using a time series of normalised mosaics of aerial photographs dating back from 1950, field inquiries, and updated groundwater data. The 500 km2 study area in southwest Niger was chosen (i) for its rural environment representative of the rain-fed agriculture belt of the Sahel and (ii) to encompass the main hydrological study sites investigated in this region over the past two decades (Hapex-Sahel and AMMA experiments, 1990-2000s). Results have significant implications for future freshwater availability and food security in the Sahel. Between 1950 and 1992, {\textbackslash}textasciitilde 80\% of the study area has been cleared, firstly to open new areas for agriculture and secondly for firewood supply (59\% of the plateaux, 42\% of the valley bottoms, and 87\% of the hillslopes). Intermediate aerial photograph surveys (1960, 1975) attest an accelerated loss in the woody savannah that could not be recovered on the short term. A strong, indirect impact of land clearance is observed on the water resources. Land clearance has resulted in a modification of the soil properties and infiltration capacity and has led to an increase in Hortonian runoff collected in numerous gullies and ponds. Between 1950 and 1992, aerial photographs show a {\textbackslash}textasciitilde 2.5 fold increase of the drainage density with the development of large drainage systems and new ponds. Groundwater data also indicate a continuous rise in the water table, mostly noticeable since the 1980s with a mean groundwater level rise of {\textbackslash}textasciitilde 4 m for the 1963-2005 period (+ 15\% in aquifer reserves). The relatively short {\textbackslash}textasciitilde 30 year time-lag between the onset of land clearance and the beginning of the water table rise is linked to the process of indirect groundwater recharge and is timed with the connectivity of the drainage network and the formation of new ponds. Finally, the sustained increase in surface runoff and groundwater recharge during the past four decades indicates that the indirect impact of land clearance on the terrestrial water balance has been stronger than that of the long-lasting Sahelian drought. As the rate of land clearance increased for the past century in semiarid Africa, its main hydrological effects may not yet be fully perceptible.},
	number = {3-4},
	urldate = {2010-12-03},
	journal = {Global and Planetary Change},
	author = {Leblanc, Marc J. and Favreau, Guillaume and Massuel, Sylvain and Tweed, Sarah O. and Loireau, Maud and Cappelaere, Bernard},
	month = apr,
	year = {2008},
	keywords = {West Africa, remote sensing, Land use, AMMA-CATCH, Niger, Hapex-Sahel, climate change and feedbacks, global change, gully erosion, semiarid area},
	pages = {135--150},
}

@article{cappelaere_amma-catch_2009,
	title = {The {AMMA}-{CATCH} experiment in the cultivated {Sahelian} area of south-west {Niger} - {Investigating} water cycle response to a fluctuating climate and changing environment},
	volume = {375},
	issn = {0022-1694},
	url = {http://apps.isiknowledge.com/full_record.do?product=WOS&search_mode=GeneralSearch&qid=1&SID=Y1a3kLPaIOHdJpjgG2K&page=1&doc=4},
	doi = {10.1016/j.jhydrol.2009.06.021},
	abstract = {Among the three sites distributed along the West African latitudinal gradient in the AMMA-CATCH observation system, the experimental setup in the Niamey area of south-west Niger samples the cultivated Sahel environment, for hydrological, vegetation and land surface processes. The objective is to investigate relationships between climate, land cover, and the water cycle, in a rapidly changing semiarid environment. This paper first presents the main characteristics of the area, where previous research, including the EPSAT and HAPEX-Sahel experiments, had evidenced a widespread decadal increase in water resources, concurrently with severe drought conditions. The specifics of AMMA-CATCH research and data acquisition at this site, over the long-term (similar to 2001-2010) and enhanced (similar to 2005-2008) observation periods, are introduced. Objectives and observation strategy are explained, and the main characteristics of instrument deployment are detailed. A very large number of parameters - covering rainfall, vegetation ecophysiology, phenology and production, surface fluxes of energy, water vapour and CO2, runoff and sediment, pond water, soil moisture, and groundwater - were monitored at local to meso scales in a nested structure of sites. The current state of knowledge is summarized, connecting processes and patterns of variation for rainfall, vegetation/land cover, and the terrestrial hydrologic cycle. The central role of land use and of its spectacular change in recent decades is highlighted. This paper provides substantial background information that sets the context for papers relating to the south-west Niger site in this AMMA-CATCH special issue. (C) 2009 Elsevier B.V. All rights reserved.},
	number = {1-2},
	urldate = {2011-04-08},
	journal = {Journal of Hydrology},
	author = {Cappelaere, B. and Descroix, L. and Lebel, T. and Boulain, N and Ramier, D. and Laurent, J-P. and Favreau, G. and Boubkraoui, S. and Boucher, M. and Moussa, I.B. and Chaffard, V. and Hiernaux, P. and Issoufou, H.B.A. and Le Breton, E. and Mamadou, I. and Nazoumou, Y. and Oi, M. and Ottle, . and Quantin, G.},
	month = aug,
	year = {2009},
	keywords = {Water resources, rainfall, AMMA-CATCH, Niger, HYBIS, Runoff generation, endoreic catchment, hydrologic process simulation, long-term rise, Ecohydrology, hapex-sahel, Land cover change, Observation system, Recharge, sandy soils, Savanna vegetation, Semiarid, semiarid niger, systems},
	pages = {34--51},
}

@article{depraetere_organization_2009,
	title = {The organization and kinematics of tropical rainfall systems ground tracked at mesoscale with gages: {First} results from the campaigns 1999-2006 on the {Upper} {Oueme} {Valley} ({Benin})},
	volume = {375},
	issn = {0022-1694},
	shorttitle = {The organization and kinematics of tropical rainfall systems ground tracked at mesoscale with gages},
	url = {http://apps.isiknowledge.com/full_record.do?product=WOS&search_mode=GeneralSearch&qid=1&SID=Y1a3kLPaIOHdJpjgG2K&page=1&doc=6},
	doi = {10.1016/j.jhydrol.2009.01.011},
	abstract = {A dense network of rain gages, set up in the Upper Oueme Valley in Benin is used to study the spatial organization and the kinematics of the convective systems that cross the region. The study area is situated under Soudanian climate and set up as part of the AMMA-CATCH (African Monsoon Multidisciplinary Analysis - Couplage de l'Atmosphere Tropicale et du Cycle Hydrologique) observing system. Previous works focusing on the rainy events that occur in the Sahelian region of Niamey have shown that most of the rainfall in that region is provided by Organized Convective System that cover several thousand km(2) and usually propagate with a strong westward component. It was shown also that the time evolution of these Sahelian rainy events usually exhibits a convective peak followed by longer lasting and weaker stratiform rainfall. The aim of the present study is to analyze the spatial organization and kinematics of the rainy events occurring further south under the distinct, much more humid, Soudanian climate. These events have been poorly documented so far and the extent to which the Soudanian rainfall events behave like their Sahelian counterparts remains unclear. Seven years of rainfall data gathered over the AMMA-CATCH Benin site are studied. A new method called the 'Average Synchronized Hyetograph' (ASH) is proposed to analyze the kinematics of the rain patterns. The method also allows the assessment of the spatial organization of the system. A classification of the rainy events is proposed. It is based on assessing if (i) the rain patterns show a global propagation velocity and direction and (ii) if the time evolution of the rain rate within the network is typical of organized tropical Mesoscale Convective Systems (MCS) with a well-defined convective peak. The present study shows that about 55\% of the events have a signature typical of those of MCS. Conversely, about 27\% of rainfall events do not show evidence of being associated with MCS or even propagating. The kinematic properties of the events classified as MCS appear to be globally consistent with what was observed for the Sahelian zone from satellite tracking; the dominant direction is south-southwest but with a large departure from this average trend; their velocity ranges mostly between 20 and 50 km/h but a significant number of events are faster than that. MCS remains the dominant type of events during the whole rainy season but the period between mid July and mid August. The classification of rainfall events resulting from ground tracking has been compared with METEOSAT satellite tracking for the years 2003 and 2004. There is a significant correspondence of classes of rainfall events between the two tracking methods despite differences of scales and criterions in their definition. (C) 2009 Elsevier B.V. All rights reserved.},
	number = {1-2},
	urldate = {2011-04-08},
	journal = {Journal of Hydrology},
	author = {Depraetere, C and Gosset, M and Ploix, S and Laurent, H},
	month = aug,
	year = {2009},
	keywords = {Sahel, convective systems, AMMA-CATCH, HYBIS, benin, west-africa, convective system, fields, Ground tracking, Kinematics, Rainfall classification, Soudanian zone, synoptic weather system, Tropical rain, variability},
	pages = {143--160},
}

@article{guichard_surface_2009,
	title = {Surface thermodynamics and radiative budget in the {Sahelian} {Gourma}: {Seasonal} and diurnal cycles},
	volume = {375},
	issn = {0022-1694},
	shorttitle = {Surface thermodynamics and radiative budget in the {Sahelian} {Gourma}},
	url = {http://apps.isiknowledge.com/full_record.do?product=WOS&search_mode=GeneralSearch&qid=1&SID=Y1a3kLPaIOHdJpjgG2K&page=1&doc=7},
	doi = {10.1016/j.jhydrol.2008.09.007},
	abstract = {Our understanding of the role of surface-atmosphere interactions in the West African monsoon has been particularly limited by the scarcity of measurements. The present study provides a quantitative analysis of the very pronounced seasonal and diurnal cycles of surface thermodynamics and radiative fluxes in the Central Sahel. It makes use of data collected from 2002 to 2007 in the Malian Gourma, close to Agoufou, at 1.5 degrees W-15.3 degrees N and sounding data collected during the AMMA field campaign. The seasonal cycle is characterized by a broad maximum of temperature in May, following the first minimum of the solar zenith angle (SZA) by a few weeks, when Agoufou lies within the West African Heat Low, and a late summer maximum of equivalent potential temperature (0e) within the core of the monsoon season, around the second yearly maximum of SZA. Distinct temperature and moisture seasonal and diurnal dynamics lead to a sharpening of the early (late) monsoon increase (decrease), more steadiness of 0e and larger changes of relative humidity in between. Rainfall starts after the establishment of the monsoon flow, once temperature already started to decrease slowly, typically during June. Specific humidity increases progressively from May until August, while the monsoon flow weakens during the same period. Surface net radiation (R-net) increases from around 10-day mean values of 20 W m(-2) in Winter to 120-160 W m(-2) in late Summer, The increase is sharper during the monsoon than before, and the decrease fast. The seasonal cycle of R-net arises from distinct shortwave and longwave fluctuations that are both strongly shaped by modifications of surface properties related to rainfall events and vegetation phenology (with a decrease of both surface longwave emission and albedo). During the monsoon, clouds and aerosols reduce the incoming solar radiation by 20-25\% (about 70 W m(-2)). They also significantly enhance the day-to-day variability of R-net. Nevertheless, the surface incoming longwave radiative flux (LWin) is observed to decrease from June to September. As higher cloud covers and larger precipitable water amounts are typically expected to enhance LWin, this feature points to the significance of changes in atmospheric temperature and aerosols during the monsoon season. The strong dynamics associated with the transition from a drier hot Spring to a brief cooler moist tropical Summer climate involves large transformations of the diurnal cycle, even within the monsoon season, which significantly affect both thermodynamical, dynamical and radiative fields (and low-level dynamics). In particular, for all moist Summer months except August, specific humidity decreases in such a way during daytime that it prevents an afternoon increase of 0e. In agreement with some previous studies, strong links are found between moisture and LWnet all year long and a positive correlation is identified between R-net and 0e during the monsoon. The observational results presented in this study further provide valuable ground truth for assessing models over an area displaying a rich variety of surface-atmosphere regimes. (C) 2008 Elsevier B.V. All rights reserved.},
	number = {1-2},
	urldate = {2011-04-08},
	journal = {Journal of Hydrology},
	author = {Guichard, F and Kergoat, L and Mougin, E and Timouk, F and Baup, F and Hiernaux, P and Lavenu, F},
	month = aug,
	year = {2009},
	keywords = {AMMA-CATCH, ext1, Mali},
	pages = {161--177},
}

@article{hiernaux_trends_2009,
	title = {Trends in productivity of crops, fallow and rangelands in {Southwest} {Niger}: {Impact} of land use, management and variable rainfall},
	volume = {375},
	issn = {0022-1694},
	shorttitle = {Trends in productivity of crops, fallow and rangelands in {Southwest} {Niger}},
	url = {http://www.sciencedirect.com/science/article/B6V6C-4VGXCXK-4/2/dbfe0de8a6e00b0c6c653fbe6eaa0ebc},
	doi = {10.1016/j.jhydrol.2009.01.032},
	abstract = {{\textbackslash}textlessp{\textbackslash}textgreaterSummary{\textbackslash}textlessbr/{\textbackslash}textgreaterTo document trends in land use and herbaceous production, 71 field sites sampled among cropped fields, fallow fields and rangelands in the Fakara region (Niger) were monitored from 1994 to 2006. The overall trend in land use confirmed the historical increase of the cropped areas since mid 20th century, at an annual rate of 2\% from 1994 to 2006. This trend is the result of changes in the relative extent of fields permanently cropped and fields under shifting cultivation, and for the latter, the relative proportion of short (3 years) and long (10 years) duration fallows. Type of land use together with topography and soil type determine the herbaceous production and the resulting yield measured towards the end of the wet season. The variation in site yields between years is of the same order of magnitude as the variation in yields between sites within a year. There is an overall decreasing trend in site yields by 5\% annually from 1994 to 2006 that is not explained by variations in rainfall. The decreasing trend is observed on fields under shifting cultivation, fallowed fields and rangelands, although not all sites are equally affected. Causes are likely to be multiple which might include changes in land use, decline of soil fertility and increased grazing pressure. Indeed, the remaining rangelands on marginal land and the fallows still accessible to livestock are subject to such a heavy grazing during the rainy season that the herbaceous standing mass measured at the end of the season reflects poorly the actual production. After the two first years of cropping, the herbaceous yield in fields under shifting cultivation with no fertilisation is negatively affected by the number of successive years of cropping. Moreover, clearing fallow after a decreasing number of years affects the mean herbaceous yield of fallowed fields by reducing the contribution of more productive old fallows. Changes in land use, grazing pressure and soil fertility also triggered changes in species composition with a strong reduction in diversity from rangelands to fallows, and again from fallows to cropland weeds. No correlations was found however between productivity and species composition. Cumulative rainfall does not explain between site or between year deviations in herbaceous yield even when sites are sorted by land use type or by soil type in the case of fallow and rangelands. Simulated production calculated with the STEP model does not explain herbaceous yields much better even when sites are grouped by land use and soil type. However, relative changes of herbaceous yields are reasonably predicted on sites that remained fallowed and were not heavily grazed for at least four consecutive years.{\textbackslash}textless/p{\textbackslash}textgreater},
	number = {1-2},
	urldate = {2011-04-08},
	journal = {Journal of Hydrology},
	author = {Hiernaux, Pierre and Ayantunde, Augustine and Kalilou, Adamou and Mougin, Eric and Gérard, Bruno and Baup, Frédéric and Grippa, Manuela and Djaby, Bakary},
	month = aug,
	year = {2009},
	keywords = {Sahel, Land use, AMMA-CATCH, Fallows, Millet crops, Vegetation dynamics, Vegetation growth modelling},
	pages = {65--77},
}

@article{hiernaux_woody_2009,
	title = {Woody plant population dynamics in response to climate changes from 1984 to 2006 in {Sahel} ({Gourma}, {Mali})},
	volume = {375},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/B6V6C-4VP4TRR-2/2/e03cc95de44a66852733e22b22f0c30f},
	doi = {10.1016/j.jhydrol.2009.01.043},
	abstract = {{\textbackslash}textlessp{\textbackslash}textgreaterSummary{\textbackslash}textlessbr/{\textbackslash}textgreaterThe patterns of the changes in woody plant population densities, size and species composition is documented and discussed for 24 rangeland sites monitored from 1984 to 2006 in Gourma (Mali). The sites are sampled along the North-South bioclimatic gradient on each of the main soils and levels of grazing intensity. Site woody plant populations range from extremely sparse on shallow soils, to scattered on sandy soils, to open forest in temporarily flooded clayed soils, and to narrow thickets on hard pans. Three different methods contributed to assess and monitor woody plant density and canopy cover.{\textbackslash}textlessbr/{\textbackslash}textgreaterIn the short term woody populations were struck by the 1983-1984 droughts irrespective of their edaphic situation and location along the bioclimatic gradient. Drought induced mortality was not more severe under drier climate within the Sahel gradient but occurred sooner after drought in shallow soils, and with a lag of a year or two on flooded clay soils. No evidences were found of higher mortality rates in stands with history of intense grazing. Although rainfall remained below average for a decade after the drought, active recruitment of woody plants occurred in all sites starting as soon as 1985. Recruitment proceeded by successive cohorts, often with short-living perennial undershrubs and pioneer shrubs settling first. Acacia species were among the first to settle or re-establish, especially on the sites most intensively grazed. The release of competition due to drought induced mortality and to the reduction of herbaceous cover contributed to the success of the recruitment. The species composition change that resulted could first be interpreted as a shift toward a more arid tolerant flora, then some diversification occurred since the mid 1990s that could indicate a possible return to previous composition in the long term, confirming the resilience Sahel vegetation.{\textbackslash}textless/p{\textbackslash}textgreater},
	number = {1-2},
	urldate = {2011-04-08},
	journal = {Journal of Hydrology},
	author = {Hiernaux, Pierre and Diarra, Lassine and Trichon, Valérie and Mougin, Eric and Soumaguel, Nogmana and Baup, Frédéric},
	month = aug,
	year = {2009},
	keywords = {Sahel, AMMA-CATCH, Mali, Vegetation dynamics, Drought, Resilience, Tree recruitment, Woody plant population},
	pages = {103--113},
}

@article{hiernaux_sahelian_2009,
	title = {Sahelian rangeland response to changes in rainfall over two decades in the {Gourma} region, {Mali}},
	volume = {375},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/B6V6C-4TX79CH-4/2/eeb3b26622b6a3728b49492abeea4937},
	doi = {10.1016/j.jhydrol.2008.11.005},
	abstract = {{\textbackslash}textlessp{\textbackslash}textgreaterSummary{\textbackslash}textlessbr/{\textbackslash}textgreaterTwenty-five rangeland sites were monitored over two decades (1984-2006) first to assess the impact of the 1983-1984 droughts on fodder resources, then to better understand ecosystem functioning and dynamics. Sites are sampled along the south-north bioclimatic gradient in Gourma (Mali), within three main edaphic situations: sandy, loamy-clay and shallow soils. In addition, three levels of grazing pressure where systematically sampled within sandy soils. Located at the northern edge of the area reached by the West African monsoon, the Gourma gradient has recorded extremes in inter-annual variations of rainfall and resulting variations in vegetation growth. Following rainfall variability, inter-annual variability of herbaceous yield increases as climate gets dryer with latitudes at least on the sandy soils sites. Local redistribution of rainfall explains the high patchiness of herbaceous vegetation, especially on shallow soils. Yet spatial heterogeneity of the vegetation does not buffer between year yield variability that increases with spatial heterogeneity. At short term, livestock grazing during the wet season affects plant growth and thus yield in direction and proportions that vary with the timing and intensity of grazing. In the longer term, grazing also impinges upon species composition in many ways. Hence, long histories of heavy grazing promote either long cycle annuals refused by livestock or else short cycle good quality feed species. Primary production is maintained or even increased in the case of refusal such as Sida cordifolia, and is lessened in the case of short cycle species such as Zornia glochidiata. These behaviours explain that the yield anomalies calculated for the rangelands on sandy soils relative to the yield of site less grazed under similar climate tend to be negative in northern Sahel where the scenario of short cycle species dominates, while yield anomalies are close to nil in centre Sahel and slightly positive in South Sahel where the refusal scenario is more frequent. Because grazing promotes short cycle species, grazed rangelands respond faster to droughts. Year to year changes in species composition are abrupt as expected from the transient soil seed stock. However, some decadal trends in species composition are identified, with a wave of pioneer species following the 1983-1984 droughts, and a more progressive diversification and return to typical Sahel flora from 1992 onwards.{\textbackslash}textless/p{\textbackslash}textgreater},
	number = {1-2},
	urldate = {2011-04-08},
	journal = {Journal of Hydrology},
	author = {Hiernaux, Pierre and Mougin, Eric and Diarra, Lassine and Soumaguel, Nogmana and Lavenu, François and Tracol, Yann and Diawara, Mamadou},
	month = aug,
	year = {2009},
	keywords = {Sahel, AMMA-CATCH, Mali, Gourma, Vegetation dynamics, Patchiness, Yield variability},
	pages = {114--127},
}

@article{frappart_rainfall_2009,
	title = {Rainfall regime across the {Sahel} band in the {Gourma} region, {Mali}},
	volume = {375},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/B6V6C-4VTCMF6-3/2/fa1a3d2994820c72829b6ef644475640},
	doi = {10.1016/j.jhydrol.2009.03.007},
	abstract = {{\textbackslash}textlessp{\textbackslash}textgreaterSummary{\textbackslash}textlessbr/{\textbackslash}textgreaterThe Sahel is characterized by low and highly variable rainfall, which strongly affects the hydrology and the climate of the region and creates severe constraints for agriculture and water management. This study provides the first characterization of the rainfall regime for the Gourma region located in Mali, Central Sahel (14.5-17.5°N and 2-1°S). The rainfall regime is described using two datasets: the daily long term raingauge records covering the period 1950-2007, and the high frequency raingauge records collected under the African Monsoon Multidisciplinary Analysis (AMMA) project between 2005 and 2008. The first rainfall dataset was used to analyse the interannual variability and the spatial distribution of the precipitation. The second dataset is used to analyse the diurnal cycle of precipitation and the nature of the rainfall. This study is complementary to previous analyses conducted in Sahelian areas located further south, where the influence of the continental Sahara heat low is expected to be less pronounced in summer.{\textbackslash}textlessbr/{\textbackslash}textgreaterRainfall regimes in the Gourma region present a succession of wet (1950-1969) and dry decades (1970-2007). The decrease of summer cumulative rainfall is explained by a reduction in the number of the rainy days in southern Gourma, and a decrease in both the number of rainy days and the daily rainfall in northern and central Gourma. This meridional difference may be related to the relative distances of the zones from the intertropical discontinuity, which is closer to the northern stations. The length of the rainy season has varied since the 1950s with two episodes of shorter rainy seasons: during the drought of the 1980s and also since 2000. However, this second episode is characterized by an increase in the daily rainfall, which suggests an intensification of rainfall events in the more recent years.{\textbackslash}textlessbr/{\textbackslash}textgreaterHigh-frequency data reveal that a large fraction of the rainfall is produced by intense rain events mostly occurring in late evenings and early mornings during the core of the rainy season (July-September). Conversely, rainfall amounts are less around noon, and this mid-day damping is more pronounced in northern Gourma. All these characteristics have strong implications for agriculture and water resources management.{\textbackslash}textless/p{\textbackslash}textgreater},
	number = {1-2},
	urldate = {2011-04-08},
	journal = {Journal of Hydrology},
	author = {Frappart, Frédéric and Hiernaux, Pierre and Guichard, Françoise and Mougin, Eric and Kergoat, Laurent and Arjounin, Marc and Lavenu, François and Koité, Mohamed and Paturel, Jean-Emmanuel and Lebel, Thierry},
	month = aug,
	year = {2009},
	keywords = {Sahel, Precipitation, Diurnal cycle, AMMA-CATCH, Mali, HYBIS, variability, Drought, cycle, diurnal-variations, Gourma region, Interannual variability, scales, west-african sahel, wet},
	pages = {128--142},
}

@article{de_rosnay_multi-scale_2009,
	title = {Multi-scale soil moisture measurements at the {Gourma} meso-scale site in {Mali}},
	volume = {375},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/B6V6C-4VDY86R-K/2/7aabf8c09547b264f2311bba09d8c5d8},
	doi = {10.1016/j.jhydrol.2009.01.015},
	abstract = {{\textbackslash}textlessp{\textbackslash}textgreaterSummary{\textbackslash}textlessbr/{\textbackslash}textgreaterThis paper presents the ground soil moisture measurements performed over the so-called Gourma meso-scale site in Mali, Sahel, in the context of the African Monsoon Multidisciplinary Analysis (AMMA) project. The Gourma meso-scale soil moisture network is part of a complete land surface processes observing and modelling strategy and is associated to vegetation and meteorological field measurements as well as soil moisture remote sensing. It is spanning 2° in latitude between 15°N and 17°N. In 2007, it includes 10 soil moisture stations, of which three stations also have meteorological and flux measurements. A relevant spatial sampling strategy is proposed to characterise soil moisture at different scales including local, kilometer, super-site and meso-scales. In addition to the local stations network, transect measurements were performed on different coarse textured (sand to sandy-loam) sites, using portable impedance probes. They indicate mean value and standard deviation (STD) of the surface soil moisture (SSM) at the kilometer scale. This paper presents the data set and illustrates soil moisture spatial and temporal features over the Sahelian Gourma meso-scale site for 2005-2006. Up-scaling relation of SSM is investigated from (i) local to kilometer scale and (ii) from local to the super site scale. It is shown to be stable in space and time (2005-2006) for different coarse textured sites. For the Agoufou local site, the up-scaling relation captures SSM dynamics at the kilometer scale with a 0.9\% accuracy in volumetric soil moisture. At the multi-site scale, an unique up-scaling relation is shown to be able to represent kilometer SSM for the coarse textured soils of the meso-scale site with an accuracy of 2.2\% (volumetric). Spatial stability of the ground soil moisture stations network is also addressed by the Mean Relative Difference (MRD) approach for the Agoufou super site where five soil moisture stations are available (about ). This allows the identification of the most representative ground soil moisture station which is shown to be an accurate indicator with low variance and bias of the soil moisture dynamics at the scale of the super site. Intensive local measurements, together with a robust up-scaling relation make the Gourma soil moisture network suitable for a large range of applications including remote sensing and land surface modelling at different spatial scales.{\textbackslash}textless/p{\textbackslash}textgreater},
	number = {1-2},
	urldate = {2011-04-08},
	journal = {Journal of Hydrology},
	author = {de Rosnay, P. and Gruhier, C. and Timouk, F. and Baup, F. and Mougin, E. and Hiernaux, P. and Kergoat, L. and LeDantec, V.},
	month = aug,
	year = {2009},
	keywords = {AMMA, Sahel, Soil moisture, AMMA-CATCH, Mali, Ground measurements, Up-scaling},
	pages = {241--252},
}

@article{zribi_ers_2009,
	title = {{ERS} scatterometer surface soil moisture analysis of two sites in the south and north of the {Sahel} region of {West} {Africa}},
	volume = {375},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/B6V6C-4V74VP0-1/2/7ddfd8a0f1a736b449e1b7ce5dfc6e2e},
	doi = {10.1016/j.jhydrol.2008.11.046},
	abstract = {{\textbackslash}textlessp{\textbackslash}textgreaterSummary{\textbackslash}textlessbr/{\textbackslash}textgreaterThe analysis of feedback effects between continental surfaces and the atmosphere is a key element in the understanding of African monsoon dynamics. For this reason, the monitoring of surface parameters, in particular soil moisture, is essential. Satellite remote sensing appears to be the most suitable means of obtaining data relevant to such parameters. The present paper presents the results of statistical analysis of soil moisture products based on data recorded by the ERS scatterometer, over the period 1992-2006, from two sites in Niger and Mali in the Sahel climatic region. Soil moisture products were validated over these two sites using ground data measurements and ASAR/ENVISAT estimations. The soil moisture distribution during the monsoon period is described, and the temporal correlation between estimated soil moisture levels is computed. Finally, the dynamics of cells corresponding to precipitation events and high surface moisture values were evaluated in the studied regions, thereby revealing variations during the monsoon period as well as site specific trends.{\textbackslash}textless/p{\textbackslash}textgreater},
	number = {1-2},
	urldate = {2011-04-08},
	journal = {Journal of Hydrology},
	author = {Zribi, M. and Pardé, M. and De Rosnay, P. and Baup, F. and Boulain, N. and Descroix, L. and Pellarin, T. and Mougin, E. and Ottlé, C. and Decharme, B.},
	month = aug,
	year = {2009},
	keywords = {Soil moisture, AMMA-CATCH, Niger, Mali, HYBIS, AO, dynamics, ERS scatterometer, Radar, Time series analysis, Western Africa},
	pages = {253--261},
}

@article{pellarin_hydrological_2009,
	title = {Hydrological modelling and associated microwave emission of a semi-arid region in {South}-western {Niger}},
	volume = {375},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/B6V6C-4V4KR2Y-2/2/f9f803d5f7eb18be0dd91c9b3ea1ef60},
	doi = {10.1016/j.jhydrol.2008.12.003},
	abstract = {{\textbackslash}textlessp{\textbackslash}textgreaterSummary{\textbackslash}textlessbr/{\textbackslash}textgreaterStudying surface-atmosphere feedback is often limited by the accuracy of the land surface observations (particularly soil moisture estimates) or the performance of the land surface models. To further our understanding of soil moisture effects on land-atmosphere fluxes, improvements in soil moisture mapping over large regions are necessary. The aim of this study was to obtain accurate soil moisture mapping over a 120 by 100 km2 area in West Africa using the considerable amount of measurements available from local and regional scales, recorded during the African monsoon multidisciplinary analysis (AMMA) experiment. The modelling strategy was based on the use of a land surface model (LSM), employed to provide high-resolution soil moisture mapping over the studied area. A microwave emission model was then used to simulate associated microwave brightness temperatures (TB) to compare with the Advanced microwave scanning radiometer (AMSR) at the same spatial (25 by 20 km2) and temporal resolution (daily). Discrepancies between observed and simulated TB were analysed and used to calibrate the LSM and the microwave emission models to match the specific hydrology and soil microwave behaviour of the studied area. Nevertheless, a positive bias of the near-surface soil moisture remained and the land surface model was still unable to reproduce the rapid dynamic of the near-surface soil moisture observed at the local and regional scales in this climatic context. To solve this problem, a secondary surface soil layer was added to match in situ soil moisture measurements as well as satellite microwave measurements. Additionally, the choice of the soil permittivity model was found to be of prior importance in order to perform suitable microwave brightness temperatures. Finally, a soil moisture retrieval algorithm based on AMSR and meteosat second generation (MSG) measurements was proposed in order to improve the quality of the soil moisture estimates over the studied area (the root mean square error decreases from 5.4 \% vol. to 2.8 \% vol).{\textbackslash}textless/p{\textbackslash}textgreater},
	number = {1-2},
	urldate = {2011-04-08},
	journal = {Journal of Hydrology},
	author = {Pellarin, T. and Laurent, J.P. and Cappelaere, B. and Decharme, B. and Descroix, L. and Ramier, D.},
	month = aug,
	year = {2009},
	keywords = {remote sensing, AMMA, Soil moisture, AMMA-CATCH, HYBIS, hapex-sahel, part i, AMSR, AMSR-E, atmosphere coupling experiment, brightness temperatures, force-restore method, Hydraulic conductivity, ISBA, simple parameterization, soil-moisture retrieval, surface scheme},
	pages = {262--272},
}

@article{vischel_conditional_2009,
	title = {Conditional simulation schemes of rain fields and their application to rainfall-runoff modeling studies in the {Sahel}},
	volume = {375},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/B6V6C-4VNH49K-9/2/50ba4f8db6184d677d3de2c29c1c88c2},
	doi = {10.1016/j.jhydrol.2009.02.028},
	abstract = {{\textbackslash}textlessp{\textbackslash}textgreaterSummary{\textbackslash}textlessbr/{\textbackslash}textgreaterIn regions characterized by a great inter-annual variability or by decadal-scale changes of the rainfall regime, the simulation of long series of rainfall events is an efficient way to explore the runoff fluctuations or modifications resulting from this rainfall variability. In a context of great uncertainty regarding the Sahelian rainfall regime in a changing climate, a coherent stochastic framework is presented here to produce high spatial resolution rain fields in order to force a rainfall-runoff model and to perform sensitivity analyses. The focus of the paper is on the comparison of various conditioning methods reflecting the various types of information available for the study of past situations (data from rain gage and satellite) as well as of future scenarios (outputs of atmospheric models).{\textbackslash}textlessbr/{\textbackslash}textgreaterVarious types of rainfall simulations are performed over a 13 year period, using four levels of conditioning information obtained from a 15 gauge network covering a 60 × 60 km2 region. These simulations are then used as inputs to a Hortonian rainfall-runoff model. The simulation relevance is first assessed by studying the simulated rain field series (event time-step mean characteristics, seasonal cycle and inter-annual variability) in comparison with reference rain fields estimated by kriging. This shows that the conditioning of the simulations, even by a minimal information provided by a unique station, is of great relevance for constraining the stochastic dispersion and thus to retrieve the rainfall variability at the considered scales. Significant differences are reported between runoff obtained by the different types of created rain fields, one of the most noticeable being that runoff obtained from kriging is 25\% lower than runoff obtained from point conditional simulations. The results confirm the sensitivity of Hortonian hydrological systems to rainfall intensity and particularly point out the importance of representing realistic spatial rainfall patterns to force hydrological models.{\textbackslash}textless/p{\textbackslash}textgreater},
	number = {1-2},
	urldate = {2011-04-08},
	journal = {Journal of Hydrology},
	author = {Vischel, Théo and Lebel, Thierry and Massuel, Sylvain and Cappelaere, Bernard},
	month = aug,
	year = {2009},
	keywords = {Sahel, AMMA-CATCH, scale, HYBIS, basin response, Conditional simulations, covariance-matrix, gaussian random functions, generation, Geostatistics, part 1, Rainfall-runoff modeling, space, Spatial variability, Stochastic simulation of rain fields, time, water-balance},
	pages = {273--286},
}

@article{saux-picart_water_2009,
	title = {Water and energy budgets simulation over the {AMMA}-{Niger} super-site spatially constrained with remote sensing data},
	volume = {375},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/B6V6C-4VDH928-2/2/8a3ff22171240257dfe86bf63c8581b2},
	doi = {10.1016/j.jhydrol.2008.12.023},
	abstract = {{\textbackslash}textlessp{\textbackslash}textgreaterSummary{\textbackslash}textlessbr/{\textbackslash}textgreaterThe SEtHyS\_Savannah model [Saux-Picart et al., submitted for publication. SEtHyS\_Savannah: a multiple source land surface model applied to sahelian landscapes. Agricultural and Forest Meteorology] was developed as an extension of the SEtHyS land surface model to simulate the water and energy fluxes over dry savannah landscapes. The vegetation cover is represented by a two layer model and a mulch approach is used for the soil description. The SEtHyS\_Savannah model was regionalized over the AMMA-Niger super-site (about 50 km by 40 km), with the help of remote sensing data. The model uses a regular 1km grid and each cell is divided in sub-grid patches in order to represent land cover and soil heterogeneities (tile approach). The vegetation cover parameters were prescribed according to the land cover map and the seasonal evolution of the Leaf Area Index (LAI), both derived from SPOT-HRV (Satellite Pour l'Observation de la Terre - High Resolution Visible) data imagery. The atmospheric forcing was assumed homogeneous over the area and provided by a meteorological station installed at the Fakara experimental site. The surface water and energy budgets were simulated over a one-year period (2005) at a 5-min time step and validated against MSG-SEVIRI (Meteosat Second Generation - Spinning Enhanced Visible and Infra-red Imager) land surface temperature and ENVISAT-ASAR (ENVIronnement SATellite - Advanced Synthetic Aperture Radar) soil humidity products. The results show realistic surface fluxes and good agreement with the MSG-SEVIRI temperature observations. The soil moisture comparison presents significant correlation but large root mean square errors. These discrepancies are the consequence of both the use of a non-spatialized atmospheric forcing and to residual vegetation effects on the radar signal. Despite these uncertainties, the results increase confidence in the model representation of Sahelian soil-vegetation processes and open new perspectives to quantify the effects of vegetation changes on evapotranspiration and runoff over the region.{\textbackslash}textless/p{\textbackslash}textgreater},
	number = {1-2},
	urldate = {2011-04-08},
	journal = {Journal of Hydrology},
	author = {Saux-Picart, S. and Ottlé, C. and Decharme, B. and André, C. and Zribi, M. and Perrier, A. and Coudert, B. and Boulain, N. and Cappelaere, B. and Descroix, L. and Ramier, D.},
	month = aug,
	year = {2009},
	keywords = {photosynthesis, remote sensing, Surface fluxes, SVAT, Sahel, model, Savannah, AMMA-CATCH, HYBIS, Vegetation, calibration, features, layer, parameters, Plant canopy modeling, soil-moisture, stomatal conductance, surface-temperature},
	pages = {287--295},
}

@article{polcher_ammas_2011,
	title = {{AMMA}'s contribution to the evolution of prediction and decision-making systems for {West} {Africa}},
	volume = {12},
	issn = {1530261X},
	url = {http://doi.wiley.com/10.1002/asl.320},
	doi = {10.1002/asl.320},
	number = {1},
	urldate = {2011-04-08},
	journal = {Atmospheric Science Letters},
	author = {Polcher, Jan and Parker, Douglas J. and Gaye, Amadou and Diedhiou, Arona and Eymard, Laurence and Fierli, Federico and Genesio, Lorenzo and Höller, Hartmut and Janicot, Serge and Lafore, Jean-Philippe and Karambiri, Harouna and Lebel, Thierry and Redelsperger, Jean-Luc and Reeves, Claire E. and Ruti, Paolo and Sandholt, Inge and Thorncroft, Chris},
	month = jan,
	year = {2011},
	keywords = {AMMA-CATCH},
	pages = {2--6},
}

@article{lafore_progress_2011,
	title = {Progress in understanding of weather systems in {West} {Africa}},
	volume = {12},
	issn = {1530261X},
	url = {http://doi.wiley.com/10.1002/asl.335},
	doi = {10.1002/asl.335},
	number = {1},
	urldate = {2011-04-08},
	journal = {Atmospheric Science Letters},
	author = {Lafore, J.-P. and Flamant, C. and Guichard, F. and Parker, D. J. and Bouniol, D. and Fink, A. H. and Giraud, V. and Gosset, M. and Hall, N. and Höller, H. and Jones, S. C. and Protat, A. and Roca, R. and Roux, F. and Saïd, F. and Thorncroft, C.},
	month = jan,
	year = {2011},
	keywords = {AMMA-CATCH},
	pages = {7--12},
}

@article{taylor_new_2011,
	title = {New perspectives on land-atmosphere feedbacks from the {African} {Monsoon} {Multidisciplinary} {Analysis}},
	volume = {12},
	issn = {1530261X},
	url = {http://doi.wiley.com/10.1002/asl.336},
	doi = {10.1002/asl.336},
	number = {1},
	urldate = {2011-04-08},
	journal = {Atmospheric Science Letters},
	author = {Taylor, Christopher M. and Parker, Douglas J. and Kalthoff, Norbert and Gaertner, Miguel Angel and Philippon, Nathalie and Bastin, Sophie and Harris, Phil P. and Boone, Aaron and Guichard, Françoise and Agusti-Panareda, Anna and Baldi, Marina and Cerlini, Paolina and Descroix, Luc and Douville, Hervé and Flamant, Cyrille and Grandpeix, Jean-Yves and Polcher, Jan},
	month = jan,
	year = {2011},
	keywords = {Sahel, Soil moisture, rainfall, climate, AMMA-CATCH, amma campaign, HYBIS, dynamics, Vegetation, west-africa, variability, convection, impact, planetary boundary layer, surface},
	pages = {38--44},
}

@article{kergoat_remote_2011,
	title = {Remote sensing of the land surface during the {African} {Monsoon} {Multidisciplinary} {Analysis} ({AMMA})},
	volume = {12},
	issn = {1530261X},
	url = {http://doi.wiley.com/10.1002/asl.325},
	doi = {10.1002/asl.325},
	number = {1},
	urldate = {2011-04-08},
	journal = {Atmospheric Science Letters},
	author = {Kergoat, Laurent and Grippa, Manuela and Baille, Alain and Eymard, Laurence and Lacaze, Roselyne and Mougin, Eric and Ottlé, Catherine and Pellarin, Thierry and Polcher, Jan and de Rosnay, Patricia and Roujean, Jean-Louis and Sandholt, Inge and Taylor, Christopher M. and Zin, Isabella and Zribi, Mehrez},
	month = jan,
	year = {2011},
	keywords = {West Africa, remote sensing, AMMA, land surface, AMMA-CATCH, Benin, Niger, Mali, HYBIS, AO, dynamics, west-africa, region, sahelian site, senegal river-basin},
	pages = {129--134},
}

@article{paeth_progress_2011,
	title = {Progress in regional downscaling of west {African} precipitation},
	volume = {12},
	issn = {1530261X},
	url = {http://doi.wiley.com/10.1002/asl.306},
	doi = {10.1002/asl.306},
	number = {1},
	urldate = {2011-04-08},
	journal = {Atmospheric Science Letters},
	author = {Paeth, Heiko and Hall, Nicholas M.J. and Gaertner, Miguel Angel and Alonso, Marta Dominguez and Moumouni, Sounmaïla and Polcher, Jan and Ruti, Paolo M. and Fink, Andreas H. and Gosset, Marielle and Lebel, Thierry and Gaye, Amadou T. and Rowell, David P. and Moufouma-Okia, Wilfran and Jacob, Daniela and Rockel, Burkhardt and Giorgi, Filippo and Rummukainen, Markku},
	month = jan,
	year = {2011},
	keywords = {AMMA-CATCH},
	pages = {75--82},
}

@article{samain_analysis_2008,
	title = {Analysis of the in situ and {MODIS} albedo variability at multiple timescales in the {Sahel}},
	volume = {113},
	url = {http://www.agu.org/pubs/crossref/2008/2007JD009174.shtml},
	doi = {200810.1029/2007JD009174},
	urldate = {2011-05-24},
	journal = {Journal of Geophysical Research},
	author = {Samain, O. and Kergoat, L. and Hiernaux, P. and Guichard, F. and Mougin, E. and Timouk, F. and Lavenu, F.},
	month = jul,
	year = {2008},
	keywords = {AMMA-CATCH, mali},
	pages = {16 PP.},
}

@article{guichard_intercomparison_2010,
	title = {An {Intercomparison} of {Simulated} {Rainfall} and {Evapotranspiration} {Associated} with a {Mesoscale} {Convective} {System} over {West} {Africa}},
	volume = {25},
	issn = {0882-8156},
	url = {http://apps.isiknowledge.com/full_record.do?product=WOS&search_mode=GeneralSearch&qid=49&SID=W2O@@BO1B@3pDNLKH48&page=1&doc=2},
	doi = {10.1175/2009WAF2222250.1},
	abstract = {An evaluation of precipitation and evapotranspiration simulated by mesoscale models is carried out within the African Monsoon Multidisciplinary Analysis (AMMA) program. Six models performed simulations of a mesoscale convective system (MCS) observed to cross part of West Africa in August 2005. Initial and boundary conditions are found to significantly control the locations of rainfall at synoptic scales as simulated with either mesoscale or global models. When initialized and forced at their boundaries by the same analysis, all models forecast a westward-moving rainfall structure, as observed by satellite products. However, rainfall is also forecast at other locations where none was observed, and the nighttime northward propagation of rainfall is not well reproduced. There is a wide spread in the rainfall rates across simulations, but also among satellite products. The range of simulated meridional fluctuations of evapotranspiration (E) appears reasonable, but E displays an overly strong zonal symmetry. Offline land surface modeling and surface energy budget considerations show that errors in the simulated E are not simply related to errors in the surface evaporative fraction, and involve the significant impact of cloud cover on the incoming surface shortwave flux. The use of higher horizontal resolution (a few km) enhances the variability of precipitation, evapotranspiration, and precipitable water (PW) at the mesoscale. It also leads to a weakening of the daytime precipitation, less evapotranspiration, and smaller PW amounts. The simulated MCS propagates farther northward and somewhat faster within an overall drier atmosphere. These changes are associated with a strengthening of the links between PW and precipitation.},
	number = {1},
	urldate = {2011-05-24},
	journal = {Weather and Forecasting},
	author = {Guichard, F. and Asencio, N. and Peugeot, C. and Bock, O. and Redelsperger, JL. and Cui, XF. and Garvert, M. and Lamptey, B. and Orlandi, E. and Sander, J. and Fierli, F. and Gaertner, MA. and Jones, SC. and Lafore, JP. and Morse, A. and Nuret, M. and Boone, A. and Balsamo, G. and de Rosnay, P. and Decharme, B. and Harris, PP. and Berges, JC.},
	month = feb,
	year = {2010},
	keywords = {AMMA-CATCH, ext1},
	pages = {37--60},
}

@article{pierre_pluriannual_2011,
	title = {Pluriannual comparisons of satellite-based rainfall products over the {Sahelian} belt for seasonal vegetation modeling},
	volume = {116},
	url = {http://www.agu.org/pubs/crossref/2011/2011JD016115.shtml},
	doi = {201110.1029/2011JD016115},
	urldate = {2011-11-22},
	journal = {Journal of Geophysical Research},
	author = {Pierre, Caroline and Bergametti, Gilles and Marticorena, Béatrice and Mougin, Eric and Lebel, Thierry and Ali, Abdou},
	month = sep,
	year = {2011},
	keywords = {AMMA-CATCH},
	pages = {25 PP.},
}

@article{gardelle_less_2010,
	title = {Less rain, more water in ponds: a remote sensing study of the dynamics of surface waters from 1950 to present in pastoral {Sahel} ({Gourma} region, {Mali})},
	volume = {14},
	issn = {1607-7938},
	shorttitle = {Less rain, more water in ponds},
	url = {http://www.hydrol-earth-syst-sci.net/14/309/2010/},
	doi = {10.5194/hess-14-309-2010},
	number = {2},
	urldate = {2011-11-22},
	journal = {Hydrology and Earth System Sciences},
	author = {Gardelle, J. and Hiernaux, P. and Kergoat, L. and Grippa, M.},
	month = feb,
	year = {2010},
	keywords = {AMMA-CATCH, Mali},
	pages = {309--324},
}

@article{taylor_observational_1998,
	title = {Observational evidence of persistent convective-scale rainfall patterns},
	volume = {126},
	issn = {0027-0644},
	url = {http://dx.doi.org/10.1175/1520-0493(1998)126<1597:OEOPCS>2.0.CO;2},
	doi = {10.1175/1520-0493(1998)126<1597:oeopcs>2.0.co;2},
	abstract = {This paper examines observational evidence of a positive feedback between the land surface and rainfall in semiarid conditions. The novelty of the work lies in the length scale of study, investigating interactions between soil moisture patterns and deep convection at scales of less than 20 km. The feedback mechanism was proposed in a previous study to explain the development of an anomalous rainfall gradient in the West African Sahel. The aim here is to assess whether such rainfall persistence occurs elsewhere in the region. Convective-scale rainfall patterns are examined using two years of observations from a dense rain gauge network in southwest Niger. Rainfall differences are analyzed between neighboring gauges separated by 7.5-15 km. Under certain surface conditions, a positive correlation between daily and antecedent rainfall differences is established. These circumstances arise when previous storm patterns have modified local evaporation rates. Rainfall gradients in subsequent events tend to persist, reinforcing soil moisture patterns. The effect appears to be most pronounced in mature, large-scale storms. The widespread occurrence of persistence in the dataset provides strong observational evidence of a surface feedback mechanism, with surface-induced low-level humidity anomalies locally enhancing convection in passing storms. Several rainfall patterns that persist for a month are identified. These patterns are linked to surface processes and the frequency of storm passage.},
	number = {6},
	urldate = {2011-04-19},
	journal = {Monthly Weather Review},
	author = {Taylor, C.M. and Lebel, T.},
	month = jun,
	year = {1998},
	keywords = {Sahel, AMMA-CATCH, Niger},
	pages = {1597--1607},
}

@article{merbold_precipitation_2009,
	title = {Precipitation as driver of carbon fluxes in 11 {African} ecosystems},
	volume = {6},
	issn = {1726-4189},
	url = {http://www.biogeosciences.net/6/1027/2009/},
	doi = {10.5194/bg-6-1027-2009},
	number = {6},
	urldate = {2011-11-22},
	journal = {Biogeosciences},
	author = {Merbold, L. and Ardö, J. and Arneth, A. and Scholes, R. J. and Nouvellon, Y. and de Grandcourt, A. and Archibald, S. and Bonnefond, J. M. and Boulain, N. and Brueggemann, N. and Bruemmer, C. and Cappelaere, B. and Ceschia, E. and El-Khidir, H. A. M. and El-Tahir, B. A. and Falk, U. and Lloyd, J. and Kergoat, L. and Le Dantec, V. and Mougin, E. and Muchinda, M. and Mukelabai, M. M. and Ramier, D. and Roupsard, O. and Timouk, F. and Veenendaal, E. M. and Kutsch, W. L.},
	month = jun,
	year = {2009},
	keywords = {AMMA-CATCH},
	pages = {1027--1041},
}

@article{kergoat_impact_2002,
	title = {Impact of doubled {CO2} on global-scale leaf area index and evapotranspiration: {Conflicting} stomatal conductance and {LAI} responses},
	volume = {107},
	shorttitle = {Impact of doubled {CO2} on global-scale leaf area index and evapotranspiration},
	url = {http://www.agu.org/pubs/crossref/2002/2001JD001245.shtml},
	doi = {200210.1029/2001JD001245},
	urldate = {2011-11-22},
	journal = {Journal of Geophysical Research},
	author = {Kergoat, Laurent and Lafont, Sébastien and Douville, Hervé and Berthelot, Béatrice and Dedieu, Gérard and Planton, Serge and Royer, Jean-François},
	month = dec,
	year = {2002},
	keywords = {AMMA-CATCH},
	pages = {16 PP.},
}

@article{kergoat_model_1998,
	title = {A model for hydrological equilibrium of leaf area index on a global scale},
	volume = {213},
	issn = {0022-1694},
	doi = {10.1016/S0022-1694(98)00211-X},
	abstract = {In this paper, a model for hydrological equilibrium of leaf area index (LAT) is presented. The central assumption is that adaptation of vegetation to the local climate leads to a development of the canopy, which ensures a large light absorption but prevents severe soil water depletion. Particular attention has been paid to the processes which strengthen or weaken the basic LAI/evapotranspiration relationship, including soil moisture feedback on transpiration and evaporation, deciduousness of the canopy and interception losses. The annual water balance has been compared to stream flow data. A general agreement was found between simulated and observed run-off averaged over 28 large river basins. This shows that a water exchange scheme with explicit canopy processes can be used on a global scale. Vegetation aridity gradients are well defined by the hydrological equilibrium theory. An additional light availability constraint shows that the LAI, for wet tropics, some wet temperate and boreal areas, is not primarily water limited. An interesting point arises from an underestimation of the LAI and evapotranspiration in the rain forest margins and dry forests. This suggests that these areas are prone to recurrent droughts, and that drought resistance and avoidance strategies are of uppermost importance for vegetation function and therefore water cycle modelling. In particular, deep rooting may play a crucial role. The objective of modelling vegetation response to resources availability-here the water and light resources-is to improve our understanding of the biosphere as a resource-based system on a global scale, in the perspective of a change in atmospheric CO2 and corresponding climate modifications. The exact role of below-ground functioning, its links with carbon allocation, and especially the cost of deep rooting, emerge from this study as critical questions. (C) 1998 Elsevier Science B.V. All rights reserved.},
	language = {English},
	number = {1-4},
	journal = {Journal of Hydrology},
	author = {Kergoat, L},
	month = dec,
	year = {1998},
	keywords = {Leaf area index, canopy, AMMA-CATCH, satellite data, Vegetation, water-balance, soil-moisture, stomatal conductance, coniferous forests, global scale, hydrological equilibrium, land, net primary production, tropical dry forest},
	pages = {268--286},
}

@article{philippon_characterization_2007,
	title = {Characterization of the {Interannual} and {Intraseasonal} {Variability} of {West} {African} {Vegetation} between 1982 and 2002 by {Means} of {NOAA} {AVHRR} {NDVI} {Data}},
	volume = {20},
	issn = {0894-8755, 1520-0442},
	url = {http://journals.ametsoc.org/doi/abs/10.1175/JCLI4067.1},
	doi = {10.1175/JCLI4067.1},
	urldate = {2011-11-22},
	journal = {Journal of Climate},
	author = {Philippon, N. and Jarlan, L. and Martiny, N. and Camberlin, P. and Mougin, E.},
	month = apr,
	year = {2007},
	keywords = {AMMA-CATCH, ao},
	pages = {1202--1218},
}

@article{jarlan_dominant_2005,
	title = {Dominant patterns of {AVHRR} {NDVI} interannual variability over the {Sahel} and linkages with key climate signals (1982–2003)},
	volume = {32},
	url = {http://www.agu.org/pubs/crossref/2005/2004GL021841.shtml},
	doi = {200510.1029/2004GL021841},
	urldate = {2011-11-22},
	journal = {Geophysical Research Letters},
	author = {Jarlan, L. and Tourre, Y. M. and Mougin, E. and Philippon, N. and Mazzega, P.},
	month = feb,
	year = {2005},
	keywords = {AMMA-CATCH},
	pages = {4 PP.},
}

@article{jacques_monitoring_2014,
	title = {Monitoring dry vegetation masses in semi-arid areas with {MODIS} {SWIR} bands},
	volume = {153},
	issn = {00344257},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425714002764},
	doi = {10.1016/j.rse.2014.07.027},
	language = {en},
	urldate = {2014-09-23},
	journal = {Remote Sensing of Environment},
	author = {Jacques, Damien Christophe and Kergoat, Laurent and Hiernaux, Pierre and Mougin, Eric and Defourny, Pierre},
	month = oct,
	year = {2014},
	keywords = {AMMA-CATCH},
	pages = {40--49},
}

@article{jarlan_assimilation_2008,
	title = {Assimilation of {SPOT}/{VEGETATION} {NDVI} data into a sahelian vegetation dynamics model},
	volume = {112},
	issn = {0034-4257},
	url = {http://www.sciencedirect.com/science/article/pii/S003442570700329X},
	doi = {10.1016/j.rse.2007.02.041},
	abstract = {This paper presents a method to monitor the dynamics of herbaceous vegetation in the Sahel. The approach is based on the assimilation of Normalized Difference Vegetation Index (NDVI) data acquired by the VEGETATION instrument on board SPOT 4/5 into a simple sahelian vegetation dynamics model. The study region is located in the Gourma region of Mali. The vegetation dynamics model is coupled with a radiative transfer model (the SAIL model). First, it is checked that the coupled models allow for a realistic simulation of the seasonal and interannual variability of NDVI over three sampling sites from 1999 to 2004. The data assimilation scheme relies on a parameter identification technique based on an Evolution Strategies algorithm. The simulated above-ground herbage mass resulting from NDVI assimilation is then compared to ground measurements performed over 13 study sites during the period 1999–2004. The assimilation scheme performs well with 404 kg DM/ha of average error (n\&\#xa0;=\&\#xa0;126 points) and a correlation coefficient of r\&\#xa0;=\&\#xa0;0.80 (to be compared to the 463 kg DM/ha and r\&\#xa0;=\&\#xa0;0.60 of the model performance without data assimilation). Finally, the sensitivity of the herbage mass model estimates to the quality of the meteorological forcing (rainfall and net radiation) is analyzed thanks to a stochastic approach.},
	number = {4},
	urldate = {2011-11-22},
	journal = {Remote Sensing of Environment},
	author = {Jarlan, L. and Mangiarotti, S. and Mougin, E. and Mazzega, P. and Hiernaux, P. and Le Dantec, V.},
	month = apr,
	year = {2008},
	keywords = {Data assimilation, Sahel, AMMA-CATCH, NDVI, ao, AO, Vegetation, Evolution strategies},
	pages = {1381--1394},
}

@article{jarlan_analysis_2008,
	title = {Analysis of leaf area index in the {ECMWF} land surface model and impact on latent heat and carbon fluxes: {Application} to {West} {Africa}},
	volume = {113},
	shorttitle = {Analysis of leaf area index in the {ECMWF} land surface model and impact on latent heat and carbon fluxes},
	url = {http://www.agu.org/pubs/crossref/2008/2007JD009370.shtml},
	doi = {200810.1029/2007JD009370},
	urldate = {2011-11-22},
	journal = {Journal of Geophysical Research},
	author = {Jarlan, L. and Balsamo, G. and Lafont, S. and Beljaars, A. and Calvet, J. C. and Mougin, E.},
	month = dec,
	year = {2008},
	keywords = {AMMA-CATCH, ao},
	pages = {22 PP.},
}

@article{mougin_regional_1995,
	title = {A regional {Sahelian} grassland model to be coupled with multispectral satellite data. {I}: {Model} description and validation},
	volume = {52},
	issn = {0034-4257},
	shorttitle = {A regional {Sahelian} grassland model to be coupled with multispectral satellite data. {I}},
	url = {http://www.sciencedirect.com/science/article/pii/0034425794001268},
	doi = {10.1016/0034-4257(94)00126-8},
	abstract = {An approach to combining remote sensing spectral measurements with an ecosystem process model is presented. In this approach, the ecosystem model is not bound by the sole use of satellite data, but integrates the latter in an explicit formulation of the main processes of vegetation functioning. A close analysis of the relationships between processes described by the model and spectral measurements can therefore be carried out, and the capability of the model to be driven by remote sensing can also be investigated. This first article presents a regional ecosystem process model for Sahelian regions. The model describes a herbaceous layer composed of only annual species. The processes of the soil-plant-atmosphere system, such as water fluxes in the soil, evaporation, transpiration, photosynthesis, respiration, senescence, litter production, and litter decomposition at the soil surface, are modeled. Moreover, structural parameters such as vegetation cover fraction, LAI, and canopy height, which are essential parameters for coupling with physical models of reflectivity, are also simulated. Comparison with aboveground biomass measured between 1976 and 1992 at a regional scale in two different regions of the Sahel, namely, Ferlo in Senegal and Gourma in Mali, shows that the model is able to simulate the temporal evolution of the aboveground biomass components.},
	number = {3},
	urldate = {2011-11-22},
	journal = {Remote Sensing of Environment},
	author = {Mougin, E. and Lo Seena, D. and Rambal, S. and Gaston, A. and Hiernaux, P.},
	month = jun,
	year = {1995},
	keywords = {Sahel, model, AMMA-CATCH, Mali, Senegal},
	pages = {181--193},
}

@article{mougin_estimation_2014,
	title = {Estimation of {LAI}, {fAPAR} and {fCover} of {Sahel} rangelands ({Gourma}, {Mali})},
	volume = {198-199},
	issn = {01681923},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S016819231400197X},
	doi = {10.1016/j.agrformet.2014.08.006},
	language = {en},
	urldate = {2014-09-23},
	journal = {Agricultural and Forest Meteorology},
	author = {Mougin, E. and Demarez, V. and Diawara, M. and Hiernaux, P. and Soumaguel, N. and Berg, A.},
	month = nov,
	year = {2014},
	keywords = {AMMA-CATCH, Mali},
	pages = {155--167},
}

@article{lebel_recent_2009,
	title = {Recent trends in the {Central} and {Western} {Sahel} rainfall regime (1990–2007)},
	volume = {375},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/pii/S0022169408005738},
	doi = {10.1016/j.jhydrol.2008.11.030},
	abstract = {Summary One motivation for setting up the CATCH (Couplage de l’Atmosphère Tropicale et du Cycle Hydrologique) project at the end of the 1990s, was to contribute to documenting the Sahelian rainfall variability at the interannual scale and to provide a fine monitoring of possible long-term trends of the rainfall regime. This paper is a first attempt at characterising the Sahelian rainfall regime of the two last decades (1990–2007) by comparison to the rainfall regime of the previous decades, namely the 20-year wet period 1950–1969 and the 20-year dry period 1970–1989. While the rainfall deficit remained unabated in the Western Sahel (1990–2007 mean equal to the 1970–1989 mean, both being lower than the 1950–1969 mean), the Central Sahel progressively recorded wetter years from the end of the 1990s, but this recovery is limited (1990–2007 average larger by 10\% than the 1970–1989 average, but still lower than the 1950–1989 average). There are also significant differences between the Western Sahel and the Central Sahel when looking at the interannual variability pattern and at the seasonal cycle. The low-frequency rainfall patterns are similar between the Western Sahel and the Central Sahel, but the interannual year-to-year variability is weakly related to each other. In the Central Sahel, the major modification of the seasonal cycle in the most recent decades was the disappearance of the well marked August peak observed during the wet period. In the Western Sahel the rainfall deficit is more or less evenly distributed all along the rainy season. The second part of the paper makes use of the CATCH-Niger recording rain gauge network in order to compare several ways of defining rainy events. The statistical properties of these various populations of rainy events are compared. It is shown that a simple CPP model allows for retrieving the statistical characteristics of point rainy events from daily rainfall series. It is also confirmed that in this area, the interannual rainfall variability is primarily linked to the year-to-year fluctuation of the number of large mesoscale rainfall events.},
	number = {1-2},
	urldate = {2011-11-30},
	journal = {Journal of Hydrology},
	author = {Lebel, Thierry and Ali, Abdou},
	month = aug,
	year = {2009},
	keywords = {AMMA-CATCH, Interannual variability, Rainfall anomaly, Seasonal cycle, West African rainfall},
	pages = {52--64},
}

@article{massuel_deep_2006,
	title = {Deep infiltration through a sandy alluvial fan in semiarid {Niger} inferred from electrical conductivity survey, vadose zone chemistry and hydrological modelling},
	volume = {67},
	doi = {10.1016/j.catena.2006.02.009},
	number = {2},
	journal = {Catena},
	author = {Massuel, S. and Favreau, G. and Descloitres, M. and Le Troquer, Y. and Albouy, Y. and Cappelaere, B.},
	year = {2006},
	keywords = {AMMA-CATCH, Niger},
	pages = {105--118},
}

@article{seghieri_is_2012,
	title = {Is water availability really the main environmental factor controlling the phenology of woody vegetation in the central {Sahel}?},
	volume = {213},
	issn = {1385-0237},
	url = {http://www.springerlink.com/content/j1gt58085672v256/abstract/},
	doi = {10.1007/s11258-012-0048-y},
	abstract = {Rainfall distribution and the soil moisture regime have been recognized to be the key drivers of the phenological rhythms in Sahelian woody plants, although different climate triggers have been assumed to be involved in determining the date of the onset of the phenophase. However, almost no comparisons have been made of the actual relative predictive power of these environmental factors. The aim of our study was to quantify the ability of several factors to predict phenophase occurrence in the dominant woody populations of northern Mali. Canopy leafing, flowering and fruiting were monitored from May 2005 to July 2007. Multiple logistic regressions were used to test the predictive power of cumulative rainfall, soil moisture, air temperature, air humidity and day length, with time lags of up to 2 months. Artificial variables derived from time lags observed in phenophases were included as predictors to account for possible auto-correlation and cross-correlation among phenophases. Surprisingly, a decrease in temperature associated with different time lags was most often found to be the strongest predictor of both leafing and reproductive phenophases. In Sahelian shrubs, morphological and physiological adaptations strongly contribute to the relative independence of their activity from water availability, leaf phenology being a way to adjust the plant water balance to current water availability and atmospheric water content. This study provides insight towards the development of a mechanistic understanding of phenological control in the Sahel, which is becoming increasingly important in the context of expected climate changes.},
	number = {5},
	urldate = {2012-04-18},
	journal = {Plant Ecology},
	author = {Seghieri, Josiane and Carreau, Julie and Boulain, Nicolas and De Rosnay, Patricia and Arjounin, Marc and Timouk, Franck},
	year = {2012},
	keywords = {West Africa, climate, AMMA-CATCH, adaptation, Mali, HYBIS, AO, Life cycle, Aridity, australian tropical savanna, Biomedical and Life Sciences, deciduous forest, desert plants, dry tropics, Environmental effect, fruiting phenology, leaf phenology, Logistic model, plant phenology, pyrotechnica forsk decne, reproductive phenology},
	pages = {861--870},
}

@article{le_barbe_rainfall_2002,
	title = {Rainfall {Variability} in {West} {Africa} during the {Years} 1950–90},
	volume = {15},
	issn = {0894-8755, 1520-0442},
	url = {http://journals.ametsoc.org/doi/abs/10.1175/1520-0442%282002%29015%3C0187%3ARVIWAD%3E2.0.CO%3B2},
	doi = {10.1175/1520-0442(2002)015<0187:RVIWAD>2.0.CO;2},
	number = {2},
	urldate = {2012-10-18},
	journal = {Journal of Climate},
	author = {Le Barbé, Luc and Lebel, Thierry and Tapsoba, Dominique},
	month = jan,
	year = {2002},
	keywords = {AMMA-CATCH},
	pages = {187--202},
}

@article{panthou_extreme_2012,
	title = {Extreme rainfall in {West} {Africa}: {A} regional modeling},
	volume = {48},
	copyright = {© 2008 American Geophysical Union},
	issn = {0043-1397},
	shorttitle = {Extreme rainfall in {West} {Africa}},
	url = {http://www.agu.org/pubs/crossref/2012/2012WR012052.shtml},
	doi = {10.1029/2012WR012052},
	abstract = {In a world of increasing exposure of populations to natural hazards, the mapping of extreme rainfall remains a key subject of study. Such maps are required for both flood risk management and civil engineering structure design, the challenge being to take into account the local information provided by point rainfall series as well as the necessity of some regional coherency. Two approaches based on the extreme value theory are compared here, with an application to extreme rainfall mapping in West Africa. The first approach is a local fit and interpolation (LFI) consisting of a spatial interpolation of the generalized extreme value (GEV) distribution parameters estimated independently at each station. The second approach is a spatial maximum likelihood estimation (SMLE); it directly estimates the GEV distribution over the entire region by a single maximum likelihood fit using jointly all measurements combined with spatial covariates. Five LFI and three SMLE methods are considered, using the information provided by 126 daily rainfall series covering the period 1950–1990. The methods are first evaluated in calibration. Then the predictive skills and the robustness are assessed through a cross validation and an independent network validation process. The SMLE approach, especially when using the mean annual rainfall as covariate, appears to perform better for most of the scores computed. Using the Niamey 104 year time series, it is also shown that the SMLE approach has the capacity to deal more efficiently with the effect of local outliers by using the spatial information provided by nearby stations.},
	language = {English},
	number = {8},
	urldate = {2012-12-12},
	journal = {Water Resources Research},
	author = {Panthou, G. and Vischel, T. and Lebel, T. and Blanchet, J. and Quantin, G. and Ali, A.},
	month = aug,
	year = {2012},
	keywords = {West Africa, 1854 Precipitation, 1817 Extreme events, AMMA-CATCH, HYBIS, annual maxima, extreme precipitation, gev, hazard mapping},
	pages = {W08501},
}

@article{pfeffer_local_2011,
	title = {Local and global hydrological contributions to time‐variable gravity in {Southwest} {Niger}},
	volume = {184},
	issn = {1365-246X},
	url = {http://onlinelibrary.wiley.com/doi/10.1111/j.1365-246X.2010.04894.x/abstract},
	doi = {10.1111/j.1365-246X.2010.04894.x},
	abstract = {Advances in methods of observation are essential to ensure a better understanding of changes in water resources considering climate variability and human activities. The GHYRAF (Gravity and Hydrology in Africa) experiments aim to combine gravimetric measurements with dense hydrological surveys to better characterize the annual water storage variability in tropical West Africa. The first absolute gravimetric measurements were performed in Southwest Niger, near a temporary pond where rapid infiltration to an unconfined aquifer occurs. As gravity is sensitive both to local and global variations of water mass distribution, the large-scale hydrological contribution to time-variable gravity has been removed using either GRACE satellite data or global hydrology models. The effect of the local water storage changes was modelled using in situ measurements of the water table, soil moisture and pond water level. The adjustment of these simulations to residual ground gravity observations helped to constrain the specific yield to a value ranging between 1.8 and 6.2 per cent. This range of value is consistent, albeit on the low side, with the aquifer water content (6–12 per cent) estimated by magnetic resonance soundings, which are known to slightly overestimate the specific yield in this geological context. The comparison of these two independent geophysical methods shows their potential to constrain the local hydrogeological parameters. Besides, this study evidences the worth of correcting the gravity signal for large-scale hydrology before recovering local water storage parameters.},
	language = {en},
	number = {2},
	urldate = {2011-12-02},
	journal = {Geophysical Journal International},
	author = {Pfeffer, Julia and Boucher, Marie and Hinderer, Jacques and Favreau, Guillaume and Boy, Jean‐Paul and de Linage, Caroline and Cappelaere, Bernard and Luck, Bernard and Oi, Monique and Le Moigne, Nicolas},
	month = feb,
	year = {2011},
	keywords = {Africa, Hydrology, AMMA-CATCH, Superconducting gravimeter, HYBIS, Water storage, aquifer characterization, semiarid niger, grace, long-term, magnetic-resonance, Permeability and porosity, Satellite geodesy, surface loads, system, Time variable gravity, west niger},
	pages = {661--672},
}

@article{pavelic_water-balance_2012,
	title = {Water-balance approach for assessing potential for smallholder groundwater irrigation in {Sub}-{Saharan} {Africa}},
	volume = {38},
	copyright = {Copyright for articles published in this journal is retained by the Water Research Commission.},
	issn = {0378-4738},
	url = {http://www.ajol.info/index.php/wsa/article/view/80969},
	doi = {10.4314/wsa.v38i3.5},
	abstract = {Strategies for increasing the development and use of groundwater for agriculture over much of Sub-Saharan Africa (SSA) are urgently needed. Expansion of small-scale groundwater irrigation offers an attractive option to smallholder farmers to overcome unreliable wet-season rainfall and enhance dry-season production. This paper presents a simple, generic groundwater-balance-based methodology that uses a set of type-curves to assist with decision making on the scope for developing sustainable groundwater irrigation supplies, and to help understand how cropping choices influence the potential areal extent of irrigation. Guidance to avoid over-exploitation of the resource is also provided. The methodology is applied to 2 sites in West Africa with contrasting climatic and subsurface conditions. At both sites the analysis reveals that there is significant potential for further groundwater development for irrigation whilst allowing provisions for other sectoral uses, including basic human needs and the environment.},
	language = {en},
	number = {3},
	urldate = {2012-12-12},
	journal = {Water SA},
	author = {Pavelic, P. and Smakhtin, V. and Favreau, G. and Villholth, K. G.},
	year = {2012},
	keywords = {Water balance, AMMA-CATCH, groundwater irrigation, over-exploitation, Sub-Saharan Africa},
	pages = {399--406},
}

@article{boucher_contribution_2009,
	title = {Contribution of geophysical surveys to groundwater modelling of a porous aquifer in semiarid {Niger}: {An} overview},
	volume = {341},
	issn = {1631-0713},
	shorttitle = {Contribution of geophysical surveys to groundwater modelling of a porous aquifer in semiarid {Niger}},
	url = {http://www.sciencedirect.com/science/article/pii/S1631071309001680},
	doi = {10.1016/j.crte.2009.07.008},
	abstract = {Subsurface geophysical surveys were carried out using a large range of methods in an unconfined sandstone aquifer in semiarid south-western Niger for improving both the conceptual model of water flow through the unsaturated zone and the parameterization of numerical a groundwater model of the aquifer. Methods included: electromagnetic mapping, electrical resistivity tomography (ERT), resistivity logging, time domain electromagnetic sounding (TDEM), and magnetic resonance sounding (MRS). Analyses of electrical conductivities, complemented by geochemical measurements, allowed us to identify preferential pathways for infiltration and drainage beneath gullies and alluvial fans. The mean water content estimated by MRS (13\%) was used for computing the regional groundwater recharge from long-term change in the water table. The ranges in permeability and water content obtained with MRS allowed a reduction of the degree of freedom of aquifer parameters used in groundwater modelling.},
	number = {10-11},
	journal = {Comptes Rendus Geoscience},
	author = {Boucher, Marie and Favreau, Guillaume and Descloitres, Marc and Vouillamoz, Jean-Michel and Massuel, Sylvain and Nazoumou, Yahaya and Cappelaere, Bernard and Legchenko, Anatoli},
	year = {2009},
	keywords = {Sahel, AMMA-CATCH, Niger, Infiltration, HYBIS, Groundwater recharge, west-africa, Recharge, region, magnetic-resonance, Magnetic Resonance Sounding (MRS), Aquifère poreux, catchment, Electrical resistivity Tomography (ERT), Electromagnetic methods (EM), hydrogeology, Méthodes électromagnétiques (EM), Porous aquifer, Sondage par résonance magnétique des protons (RMP), southwestern niger, Tomographie de résistivité électrique (TRE), transient},
	pages = {800--809},
}

@article{crow_correcting_2011,
	title = {Correcting rainfall using satellite-based surface soil moisture retrievals: {The} {Soil} {Moisture} {Analysis} {Rainfall} {Tool} ({SMART})},
	volume = {47},
	copyright = {Copyright 2011 by the American Geophysical Union.},
	issn = {1944-7973},
	shorttitle = {Correcting rainfall using satellite-based surface soil moisture retrievals},
	url = {http://onlinelibrary.wiley.com/doi/10.1029/2011WR010576/abstract},
	doi = {10.1029/2011WR010576},
	abstract = {Recently, Crow et al. (2009) developed an algorithm for enhancing satellite-based land rainfall products via the assimilation of remotely sensed surface soil moisture retrievals into a water balance model. As a follow-up, this paper describes the benefits of modifying their approach to incorporate more complex data assimilation and land surface modeling methodologies. Specific modifications improving rainfall estimates are assembled into the Soil Moisture Analysis Rainfall Tool (SMART), and the resulting algorithm is applied outside the contiguous United States for the first time, with an emphasis on West African sites instrumented as part of the African Monsoon Multidisciplinary Analysis experiment. Results demonstrate that the SMART algorithm is superior to the Crow et al. baseline approach and is capable of broadly improving coarse-scale rainfall accumulations measurements with low risk of degradation. Comparisons with existing multisensor, satellite-based precipitation data products suggest that the introduction of soil moisture information from the Advanced Microwave Scanning Radiometer via SMART provides as much coarse-scale (3 day, 1°) rainfall accumulation information as thermal infrared satellite observations and more information than monthly rain gauge observations in poorly instrumented regions.},
	language = {en},
	number = {8},
	urldate = {2013-07-10},
	journal = {Water Resources Research},
	author = {Crow, W. T. and van den Berg, M. J. and Huffman, G. J. and Pellarin, T.},
	year = {2011},
	keywords = {Data assimilation, remote sensing, Uncertainty, Precipitation, Soil moisture, model, rainfall, AMMA-CATCH, HYBIS, products, AMSR-E, ensemble kalman filter, remote-sensing data, sampling error, Sensitivity},
	pages = {n/a--n/a},
}

@article{dorigo_international_2011,
	title = {The {International} {Soil} {Moisture} {Network}: a data hosting facility for global in situ soil moisture measurements},
	volume = {15},
	issn = {1607-7938},
	shorttitle = {The {International} {Soil} {Moisture} {Network}},
	url = {http://www.hydrol-earth-syst-sci.net/15/1675/2011/},
	doi = {10.5194/hess-15-1675-2011},
	number = {5},
	urldate = {2013-05-25},
	journal = {Hydrology and Earth System Sciences},
	author = {Dorigo, W. A. and Wagner, W. and Hohensinn, R. and Hahn, S. and Paulik, C. and Xaver, A. and Gruber, A. and Drusch, M. and Mecklenburg, S. and van Oevelen, P. and Robock, A. and Jackson, T.},
	month = may,
	year = {2011},
	keywords = {AMMA-CATCH, extérieur, International Soil Moisture Network, ISMN},
	pages = {1675--1698},
}

@article{ali_sahelian_2009,
	title = {The {Sahelian} standardized rainfall index revisited},
	volume = {29},
	issn = {1097-0088},
	url = {http://onlinelibrary.wiley.com/doi/10.1002/joc.1832/abstract},
	doi = {10.1002/joc.1832},
	abstract = {The Standardized Precipitation Index (SPI) is usually defined as the arithmetic mean of the normalized precipitation recorded at several stations over a region of interest where the standard deviation computed at each station over a period of reference is used as the normalizing factor. It is common to use this index in order to diagnose whether the Sahelian region can be considered as wet or dry for a given year. There are several key factors interfering with the relevance of the SPI as a measure of how rainy is a season over the Sahel. The strong spatial variability of the Sahelian rainfall at the annual scale, the uneven distribution of the raingauge network and the mean interannual climatological gradients across the region are the most important of these factors, and their influence is studied in detail here. Using an optimal interpolation algorithm to compute the SPI, the effects of various sampling schemes are first studied showing that the SPI computed as a single mean value over the whole Sahelian region is relatively robust with respect to these effects. However, the central key question remains that computing a single mean SPI over the Sahelian region hides the strong underlying spatial variability of this index. For instance, 2006 was a significantly dry season over the Sahel as a whole, but working at the 0.5° × 0.5° resolution shows that in fact only 28\% of the area was significantly dry, while 15\% of the Sahel was significantly wet. From conditional empirical distributions a distribution function is proposed to determine the spatial distributions of the 0.5° × 0.5° SPI values for a given mean regional SPI value. Studying in detail the space–time pattern of the SPI over the 1950–2006 period, also shows that recent years are characterized by a greater interannual variability than the previous 40 years, and by a contrast between the western Sahel remaining dry and the eastern Sahel returning to wetter conditions. Copyright © 2008 Royal Meteorological Society},
	language = {en},
	number = {12},
	urldate = {2011-12-01},
	journal = {International Journal of Climatology},
	author = {Ali, Abdou and Lebel, Thierry},
	month = oct,
	year = {2009},
	keywords = {Sahel, AMMA-CATCH, AO, Drought, Spatial variability, decadal variability, rainfall index, scale issues},
	pages = {1705--1714},
}

@article{seguis_simulated_2004,
	title = {Simulated impacts of climate change and land-clearing on runoff from a small {Sahelian} catchment},
	volume = {18},
	copyright = {Copyright © 2004 John Wiley \& Sons, Ltd.},
	issn = {1099-1085},
	url = {http://onlinelibrary.wiley.com/doi/10.1002/hyp.1503/abstract},
	doi = {10.1002/hyp.1503},
	abstract = {In the Sahel, there are few long-term data series available to estimate the climatic and anthropogenic impacts on runoff in small catchments. Since 1950, land clearing has enhanced runoff. The question is whether and by how much this anthropogenic effect offsets the current drought. To answer this question, a physically based distributed hydrological model was used to simulate runoff in a small Sahelian catchment in Niger, from the 1950–1998 rain-series. The simulation was carried out for three soil surface states of the catchment (1950, 1975 and 1992). The catchment is characterized by an increase in cultivated land, with associated fallow, from 6\% in 1950 to 56\% in 1992, together with an increase in the extent of eroded land (from 7 to 16\%), at the expense of the savanna. Effects of climate and land use are first analysed separately: irrespective of the land cover state, the simulated mean annual runoff decreases by about 40\% from the wet period (1950–1969) to the dry period (1970–1998); calculated on the 1950–1998 rainfall-series, the changes that occurred in land cover between 1950 and 1992 multiplies the mean annual runoff by a factor close to three. The analysis of a joint climatic and anthropogenic change shows that the transition from a wet period under a ‘natural’ land cover (1950) to a dry period under a cultivated land cover (1992) results in an increase in runoff of the order of 30 to 70\%. At the scale of a small Sahelian catchment, the anthropogenic impact on runoff is probably more important than that of drought. This figure for relative increase in runoff contributions to ponds, preferential sites of seepage to groundwater, is less than that currently estimated for aquifer recharge, which has been causing a significant continuous water table rise over the same period. Copyright © 2004 John Wiley \& Sons, Ltd.},
	language = {en},
	number = {17},
	urldate = {2013-10-21},
	journal = {Hydrological Processes},
	author = {Séguis, L. and Cappelaere, B. and Milési, G. and Peugeot, C. and Massuel, S. and Favreau, G.},
	year = {2004},
	keywords = {Hortonian runoff, Sahel, AMMA-CATCH, climatic change, distributed modelling, land-cover change},
	pages = {3401--3413},
}

@article{baron_gcm_2005,
	title = {From {GCM} grid cell to agricultural plot: scale issues affecting modelling of climate impact},
	volume = {360},
	issn = {0962-8436},
	shorttitle = {From {GCM} grid cell to agricultural plot},
	doi = {10.1098/rstb.2005.1741},
	abstract = {General circulation models (GCM) are increasingly capable of making relevant predictions of seasonal and long-term climate variability, thus improving prospects of predicting impact on crop yields. This is particularly important for semi-arid West Africa where climate variability and drought threaten food security. Translating GCM outputs into attainable crop yields is difficult because GCM grid boxes are of larger scale than the processes governing yield, involving partitioning of rain among runoff, evaporation, transpiration, drainage and storage at plot scale. This study analyses the bias introduced to crop simulation when climatic data is aggregated spatially or in time, resulting in loss of relevant variation. A detailed case study was conducted using historical weather data for Senegal, applied to the crop model SARRA-H (version for millet). The study was then extended to a 10 degrees N-17 degrees N climatic gradient and a 31 year climate sequence to evaluate yield sensitivity to the variability of solar radiation and rainfall. Finally, a down-scaling model called LGO (Lebel-Guillot-Onibon), generating local rain patterns from grid cell means, was used to restore the variability lost by aggregation. Results indicate that forcing the crop model with spatially aggregated rainfall causes yield overestimations of 10-50\% in dry latitudes, but nearly none in humid zones, due to a biased fraction of rainfall available for crop transpiration. Aggregation of solar radiation data caused significant bias in wetter zones where radiation was limiting yield. Where climatic gradients are steep, these two situations can occur within the same GCM grid cell. Disaggregation of grid cell means into a pattern of virtual synoptic stations having high-resolution rainfall distribution removed much of the bias caused by aggregation and gave realistic simulations of yield. It is concluded that coupling of GCM outputs with plot level crop models can cause large systematic errors due to scale incompatibility. These errors can be avoided by transforming GCM outputs, especially rainfall, to simulate the variability found at plot level.},
	language = {English},
	number = {1463},
	journal = {Philosophical Transactions of the Royal Society B-Biological Sciences},
	author = {Baron, C. and Sultan, B. and Balme, M. and Sarr, B. and Traore, S. and Lebel, T. and Janicot, S. and Dingkuhn, M.},
	month = nov,
	year = {2005},
	keywords = {West Africa, Sahel, AMMA-CATCH, west-africa, millet, Drought, system, aggregation, biomass, disaggregation, grain yield, hydrological scales, leaf-area, prediction, rain fields, tropical atlantic, use efficiency},
	pages = {2095--2108},
}

@article{mahe_rivers_2013,
	title = {The rivers of {Africa}: witness of climate change and human impact on the environment},
	volume = {27},
	issn = {0885-6087},
	shorttitle = {The rivers of {Africa}},
	doi = {10.1002/hyp.9813},
	abstract = {In this paper, we study the impact of climate change on river regimes in several parts of Africa, and we look at the most probable causes of these changes either climatically or anthropogenically driven. We study time series of updated monthly and annual runoff of rivers of North Africa, West Africa (Sahelian and humid tropical regions) and Central Africa, including the largest river basins: Niger and Volta rivers in West Africa, and Congo and Ogooue rivers in Central Africa. The recent years are studied in the perspective of multi-decadal variability. In West Africa and in a part of Central Africa, the climate has changed since 1970, and rainfall has not returned to previous annual amounts, except in Equatorial Africa. The consequences of the long-lasting drought are, depending on the area concerned, the modification of seasonal regimes (Equatorial area), the groundwater table decrease (Tropical humid area) and the land cover degradation (Sahelian area). The increasing number of dams and of agricultural areas also plays a major role on the modification of river regimes. The population increase will continue to impact on the environment: land cover change, deforestation, agriculture and increasing number of dams will be associated with a reduction of water and sediment discharges to the sea, and major impacts on downstream ecosystems and coastal areas. It seems necessary to share with stakeholders a comprehensive approach of the water cycle from the basin to the sea, to prevent long-lasting damages to ecosystems and infrastructures. Copyright (c) 2013 John Wiley \& Sons, Ltd.},
	language = {English},
	number = {15},
	journal = {Hydrological Processes},
	author = {Mahe, G. and Lienou, G. and Descroix, L. and Bamba, F. and Paturel, J. E. and Laraque, A. and Meddi, M. and Habaieb, H. and Adeaga, O. and Dieulin, C. and Kotti, F. Chahnez and Khomsi, K.},
	month = jul,
	year = {2013},
	keywords = {Africa, Land cover, AMMA-CATCH, climate change, HYBIS, burkina-faso, west-africa, variability, challenge program, dams, food cpwf basins, hydrological regimes, land-use, nakambe river, niger river, river regime, rivers, water-resources},
	pages = {2105--2114},
}

@article{descroix_experimental_2012,
	title = {Experimental evidence of deep infiltration under sandy flats and gullies in the {Sahel}},
	volume = {424–425},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/pii/S0022169411008043},
	doi = {10.1016/j.jhydrol.2011.11.019},
	abstract = {Despite the strong reduction in rainfall observed after 1968, the water table of some endorheic areas in the Sahel has been found to be rising over the last several decades. It has been previously demonstrated that this is due to land use changes which have led to a severe increase in runoff and erosion. In such areas, the excess in runoff causes a strong increase in the number of ponds, their sizes and thus, their duration. Ponds have been identified as the main zones of deep infiltration of water. The aim of this study was to investigate whether other areas of the Sahelian region could also be defined as deep infiltration ones as well, and then, whether they were contributing to aquifer recharge. Soil water content was surveyed for five consecutive years (2004–2008) by implementing a set of measurement devices at different depths. The hydrologic water balance was monitored at stream flow gauge stations located upstream and downstream of two small endorheic catchments. The observed replacement of bush vegetation by crops and fallow areas led to the appearance of extended bare soil areas due to both aeolian and hydric erosion, triggering a strong reduction in soil infiltrability under millet fields and fallow lands as well as in the soil water holding capacity. It also resulted in the formation of a great number of gullies and sand sediment deposits in the endorheic areas. Measurements showed that sandy deposits correspond in fact to large areas of deep infiltration: tens of thousands of cubic meters of water infiltrated catchments of less than 1 km2. Runoff decreased by up to 50\% in the sandy deposit areas, while infiltration (close to 1300 mm h−1) was observed up to depths of 10 m. These factors would raise the water table and significantly modify the surface and sub-surface components of the water cycle.},
	urldate = {2014-02-27},
	journal = {Journal of Hydrology},
	author = {Descroix, L. and Laurent, J. -P. and Vauclin, M. and Amogu, O. and Boubkraoui, S. and Ibrahim, B. and Galle, S. and Cappelaere, B. and Bousquet, S. and Mamadou, I. and Le Breton, E. and Lebel, T. and Quantin, G. and Ramier, D. and Boulain, N.},
	month = mar,
	year = {2012},
	keywords = {Runoff, AMMA-CATCH, Niger, HYBIS, Deep infiltration, Endorheic area, Sandy soil},
	pages = {1--15},
}

@article{richard_interplay_2013,
	title = {Interplay of riparian forest and groundwater in the hillslope hydrology of {Sudanian} {West} {Africa} (northern {Benin})},
	volume = {17},
	issn = {1607-7938},
	url = {http://www.hydrol-earth-syst-sci.net/17/5079/2013/},
	doi = {10.5194/hess-17-5079-2013},
	number = {12},
	urldate = {2014-02-27},
	journal = {Hydrol. Earth Syst. Sci.},
	author = {Richard, A. and Galle, S. and Descloitres, M. and Cohard, J.-M. and Vandervaere, J.-P. and Séguis, L. and Peugeot, C.},
	month = dec,
	year = {2013},
	keywords = {AMMA-CATCH, HYBIS, benin},
	pages = {5079--5096},
}

@article{mamadou_energy_2014,
	title = {Energy fluxes and surface characteristics over a cultivated area in {Benin}: daily and seasonal dynamics},
	volume = {18},
	issn = {1607-7938},
	shorttitle = {Energy fluxes and surface characteristics over a cultivated area in {Benin}},
	url = {http://www.hydrol-earth-syst-sci.net/18/893/2014/},
	doi = {10.5194/hess-18-893-2014},
	abstract = {Latent and sensible heat surface fluxes are key factors of the western African monsoon dynamics. However, few long-term observations of these land surface fluxes are available; these are needed to increase understanding of the underlying processes and assess their impacts on the energy and water cycles at the surface–atmosphere interface. This study analyzes turbulent fluxes of one full year, measured with the eddy covariance technique, over a cultivated area in northern Benin (western Africa). The study site is part of the long-term AMMA–CATCH (African Monsoon Multidisciplinary Analysis–Coupling of the Tropical Atmosphere and Hydrological Cycle) hydrological observatory. The flux partitioning was investigated through the evaporative fraction (EF) and the Bowen ratio (β) at both seasonal and daily scales. Finally, the surface conductance (Gs) and the decoupling coefficient (Ω) were calculated and compared with specific bare soil or canopy models. Four contrasting seasons were identified and characterized by their typical daily energy cycles. The results pointed out the contrasting seasonal variations of sensible and latent heat fluxes due to changing atmospheric and surface conditions. In the dry season, the sensible heat fluxes were largely dominant (β {\textbackslash}textasciitilde 10) and a low but significant evapotranspiration was measured (EF = 0.08); this was attributed to a few neighboring bushes, possibly fed by the water table. During the wet season, after the monsoon onset, surface conditions barely affected the evaporative fraction (EF), which remained steady (EF = 0.75); the latent heat flux was dominant and the Bowen ration (β) was about 0.4. During the dry-to-wet and wet-to-dry transition seasons, both EF and β were highly variable, as they depended on the atmospheric forcing or the response to isolated rains. A complete surface–atmosphere decoupling was never observed in 2008 (0 {\textbackslash}textless Ω {\textbackslash}textless 0.6), which suggests a systematic mixing of the air within the canopy with the atmospheric surface layer, irrespective of the atmospheric conditions and the vegetation height. Modeling approaches showed a good agreement of soil resistance with the Sakaguchi bare soil model. Canopy conductance was also well reproduced with the Ball–Berry stomata model. We showed that the skin surface temperature had a large seasonal and daily amplitude, and played a major role in all the surface processes. Consequently, an accurate modeling of the surface temperature is crucial to represent correctly the energy and water budgets for this region.},
	number = {3},
	urldate = {2014-04-19},
	journal = {Hydrol. Earth Syst. Sci.},
	author = {Mamadou, O. and Cohard, J-M. and Galle, S. and Awanou, C. N. and Diedhiou, A. and Kounouhewa, B. and Peugeot, C.},
	month = mar,
	year = {2014},
	keywords = {AMMA-CATCH, Benin, HYBIS, PHYREV},
	pages = {893--914},
}

@article{landais_combined_2010,
	title = {Combined measurements of {O}-17(excess) and d-excess in {African} monsoon precipitation: {Implications} for evaluating convective parameterizations},
	volume = {298},
	issn = {0012-821X},
	shorttitle = {Combined measurements of {O}-17(excess) and d-excess in {African} monsoon precipitation},
	doi = {10.1016/j.epsl.2010.07.033},
	abstract = {Water stable isotopes (delta O-18, delta D) are useful tools to depict and to understand the atmospheric water cycle. In tropical regions, they record the variations of convective activity and their implementation in convection schemes brings constraints on our understanding and parameterization of this phenomena. Here, we present for the first time measurements of a new isotopic marker of the hydrological cycle (O-17(excess) resulting from the combination of delta O-17 and delta O-18 of water) in convective regions on two different time scales: (i) during the African monsoon onset and intra-seasonal variability (Banizoumbou, 2006) and (ii) during the squall line of the 11th of August 2006 (Niamey). O-17(excess) responds to the monsoon onset by a similar to 30 per meg increase as well as to different convective processes in squall lines by similar to 20 per meg variations. These variations parallel those of d-excess at first order and display significant correlation with relative humidity in the lower troposphere. Still, higher correlation coefficients are observed between d-excess and relative humidity than between O-17(excess) and relative humidity, suggesting a higher influence of relative humidity on d-excess than on O-17(excess). Using a simple reevaporation model and a more sophisticated 2D model of a squall line, we show that reevaporation is the process explaining the increase of d-excess and O-17(excess) with relative humidity for these two studies. We also show that the combination of O-17(excess) and d-excess is a powerful tool to constrain the representation of isotopic processes during rain reevaporation. In turn, a good representation of such processes enables to use water isotopes to evaluate convective parameterization in atmospheric models. (C) 2010 Elsevier B.V. All rights reserved.},
	language = {English},
	number = {1-2},
	journal = {Earth and Planetary Science Letters},
	author = {Landais, A. and Risi, C. and Bony, S. and Vimeux, F. and Descroix, L. and Falourd, S. and Bouygues, A.},
	month = sep,
	year = {2010},
	keywords = {model, Water isotopes, tropics, AMMA-CATCH, HYBIS, cycle, convection, Sensitivity, African monsoon, water, climate controls, isotopic composition, moisture, reevaporation, relative humidity, stable-isotopes, summer monsoon},
	pages = {104--112},
}

@article{amogu_increasing_2010,
	title = {Increasing {River} {Flows} in the {Sahel}?},
	volume = {2},
	issn = {2073-4441},
	doi = {10.3390/w2020170},
	abstract = {Despite the drought observed since 1968 in most of the West African Sahel, runoff and rivers discharges have been increasing in the same region. This trend is related with land use change rather than climate change. This paper aims to describe the regional extension of such a phenomenon and to demonstrate that the increase in runoff is observed from the point scale up to the regional scale. It highlights the opposition of functioning between a Sahelian zone, where the Sahel's paradox applies, and the Sudanian and Guinean areas, where runoff has been logically decreasing with the rainfall. The current trend is evidenced using experimental runoff plots and discharge data from the local to the regional scales.},
	language = {English},
	number = {2},
	journal = {Water},
	author = {Amogu, Okechukwu and Descroix, Luc and Souley Yéro, Kadidiatou and Le Breton, Eric and Mamadou, Ibrahim and Ali, Abdou and Vischel, Theo and Bader, Jean-Claude and Moussa, Ibrahim Bouzou and Gautier, Emmanuele and Boubkraoui, Stephane and Belleudy, Philippe},
	month = jun,
	year = {2010},
	keywords = {Sahel, Runoff, AMMA-CATCH, climate change, HYBIS, Drought, Land use change, demography},
	pages = {170--199},
}

@article{risi_evolution_2010,
	title = {Evolution of the stable water isotopic composition of the rain sampled along {Sahelian} squall lines},
	volume = {136},
	issn = {0035-9009},
	doi = {10.1002/qj.485},
	abstract = {In the Tropics. the stable isotopic composition (HDO, H(2)(18)O) of precipitation is strongly modulated by convective activity To better understand how convective processes impact the precipitation isotopic composition, we analyze the isotopic composition of rain collected during the passage of four squall lines over the Sahel (Niamey. Niger) in August 2006 during the African Monsoon Multidisciplinary Analysis (MAMA) campaign The high-frequency sampling (5-10 mm) of the preciptation allows us to Investigate the evolution of the precipitation isotopic composition in different phases of the squall lines Despite a large variability among the different squall lines, some robust isotopic features appear the W shape of the delta(18)O evolution and the deuterium excess decrease in the first part of the sit:inform zone To understand more quantitatively how convective processes impact the precipitation isotopic composition. a simple stationary two-dimensional transport model including a representation of cloud microphysics and isotopic fractionation is developed and forced by three-dimensional winds retrieved from the Massachusetts Institute of Technology (MIT) radar on 11 August 2006 The model reproduces the robust observed features and a large sensitivity to the squall-line dynamics This model suggests that the main controlling factors of the isotopic evolution ale (1) squall-line dynamics. especially the downward advection of an at the rear of the squall lines, affecting the vapour composition and, by isotopic equilibration. the subsequent precipitation composition and (2) rain re-evaporation This suggests that water isotopes have the potential to better constrain squall-line dynamics and rain re-evaporation, and to evaluate the representation of convective processes in numerical models Copyright (C) 2009 Royal Meteorological Society},
	language = {English},
	journal = {Quarterly Journal of the Royal Meteorological Society},
	author = {Risi, Camille and Bony, Sandrine and Vimeux, Francoise and Chong, Michel and Descroix, Luc},
	month = jan,
	year = {2010},
	keywords = {AMMA, Precipitation, heat, AMMA-CATCH, simulation, HYBIS, west-africa, Radar, convection, region, moisture, copt 81, delta-o-18, general-circulation model, rain evaporation},
	pages = {227--242},
}

@article{russell_radarrain-gauge_2010,
	title = {Radar/rain-gauge comparisons on squall lines in {Niamey}, {Niger} for the {AMMA}},
	volume = {136},
	issn = {0035-9009},
	doi = {10.1002/qj.548},
	abstract = {Massachusetts Institute of Technology C-band observations are integrated with rainfall measurements from an extensive network of gauges in Niamey. Niger. West Africa. for the African Monsoon and Multidisciplinary Analysis (AMMA) The large number of gauges available enabled Z(e) - R power-law relationships for the convective and stratiform regions of individual squall lines The Z(e) - R relationships based solely on radar measurements directly vet the gauges were developed for the estimate of rainfall and attendant latent heat release (by other AMMA investigators) where gauges were unavailable The low prefactor values of the Z(e) - R power laws relative to like values for Z - R disdrometer power laws have contributions of order 1-2 dB from the use of the lowest beam tilt (0 57 degrees) and similar to 1-2 dB by the radar reading low (The sphere calibration and die Tropical Rainfall Measuring Mission TRMM - radar calibration me inconsistent at the 1-2 dB level for unknown reasons) Radar/gauge comparisons are also shown lot individual storms Accurate, unbiased results for the convective regime require adjustment of the radar-to-gauge radials for attenuation Beam filling problems and aliasing issues can often be identified in the case of out points Copyright (C) 2010 Royal Meteorological Society},
	language = {English},
	journal = {Quarterly Journal of the Royal Meteorological Society},
	author = {Russell, B. and Williams, E. R. and Gosset, M. and Cazenave, F. and Descroix, L. and Guy, N. and Lebel, T. and Ali, A. and Metayer, F. and Quantin, G.},
	month = jan,
	year = {2010},
	keywords = {Sahel, rainfall, AMMA-CATCH, HYBIS, variability, part i, attenuation, C-band radar, darwin, drop size, r relations, raindrop size distribution, rainfall estimation, Reflectivity, Z(e) - R relation},
	pages = {289--303},
}

@article{lawford_advancing_2004,
	title = {Advancing {Global}-and {Continental}-{Scale} {Hydrometeorology}: {Contributions} of {GEWEX} {Hydrometeorology} {Panel}},
	volume = {85},
	issn = {0003-0007, 1520-0477},
	shorttitle = {Advancing {Global}-and {Continental}-{Scale} {Hydrometeorology}},
	url = {http://journals.ametsoc.org/action/showMultipleAbstracts?doi=10.1175%2FBAMS-85-12-1917&href=%2Ftoc%2Fbams%2F85%2F12&mailPageTitle=Table+of+Contents+for+Bulletin+of+the+American+Meteorological+Society%3A+Volume+85+Issue+12+%3Cbr+%2F%3E+%28December+2004%29},
	doi = {10.1175/BAMS-85-12-1917},
	language = {en},
	number = {12},
	urldate = {2014-12-09},
	journal = {Bulletin of the American Meteorological Society},
	author = {Lawford, R. G. and Stewart, R. and Roads, J. and Isemer, H-J. and Manton, M. and Marengo, J. and Yasunari, T. and Benedict, S. and Koike, T. and Williams, S.},
	month = dec,
	year = {2004},
	keywords = {AMMA-CATCH, extérieur},
	pages = {1917--1930},
}

@article{oswald_hono_2013,
	title = {{HONO} {Emissions} from {Soil} {Bacteria} as a {Major} {Source} of {Atmospheric} {Reactive} {Nitrogen}},
	volume = {341},
	issn = {0036-8075, 1095-9203},
	url = {http://www.sciencemag.org/content/341/6151/1233},
	doi = {10.1126/science.1242266},
	abstract = {Abiotic release of nitrous acid (HONO) in equilibrium with soil nitrite (NO2–) was suggested as an important contributor to the missing source of atmospheric HONO and hydroxyl radicals (OH). The role of total soil-derived HONO in the biogeochemical and atmospheric nitrogen cycles, however, has remained unknown. In laboratory experiments, we found that for nonacidic soils from arid and arable areas, reactive nitrogen emitted as HONO is comparable with emissions of nitric oxide (NO). We show that ammonia-oxidizing bacteria can directly release HONO in quantities larger than expected from the acid-base and Henry’s law equilibria of the aqueous phase in soil. This component of the nitrogen cycle constitutes an additional loss term for fixed nitrogen in soils and a source for reactive nitrogen in the atmosphere. From Soil to Sky Trace gases emitted either through the activity of microbial communities or from abiotic reactions in the soil influence atmospheric chemistry. In laboratory column experiments using several soil types, Oswald et al. (p. 1233) showed that soils from arid regions and farmlands can produce substantial quantities of nitric oxide (NO) and nitrous acid (HONO). Ammonia-oxidizing bacteria are the primary source of HONO at comparable levels to NO, thus serving as an important source of reactive nitrogen to the atmosphere.},
	language = {en},
	number = {6151},
	urldate = {2014-12-09},
	journal = {Science},
	author = {Oswald, R. and Behrendt, T. and Ermel, M. and Wu, D. and Su, H. and Cheng, Y. and Breuninger, C. and Moravek, A. and Mougin, E. and Delon, C. and Loubet, B. and Pommerening-Röser, A. and Sörgel, M. and Pöschl, U. and Hoffmann, T. and Andreae, M. O. and Meixner, F. X. and Trebs, I.},
	month = sep,
	year = {2013},
	pmid = {24031015},
	keywords = {AMMA-CATCH},
	pages = {1233--1235},
}

@article{fan_global_2013,
	title = {Global {Patterns} of {Groundwater} {Table} {Depth}},
	volume = {339},
	issn = {0036-8075, 1095-9203},
	url = {http://www.sciencemag.org.gaelnomade.ujf-grenoble.fr/content/339/6122/940},
	doi = {10.1126/science.1229881},
	abstract = {Shallow groundwater affects terrestrial ecosystems by sustaining river base-flow and root-zone soil water in the absence of rain, but little is known about the global patterns of water table depth and where it provides vital support for land ecosystems. We present global observations of water table depth compiled from government archives and literature, and fill in data gaps and infer patterns and processes using a groundwater model forced by modern climate, terrain, and sea level. Patterns in water table depth explain patterns in wetlands at the global scale and vegetation gradients at regional and local scales. Overall, shallow groundwater influences 22 to 32\% of global land area, including {\textbackslash}textasciitilde15\% as groundwater-fed surface water features and 7 to 17\% with the water table or its capillary fringe within plant rooting depths.},
	language = {en},
	number = {6122},
	urldate = {2014-03-18},
	journal = {Science},
	author = {Fan, Y. and Li, H. and Miguez-Macho, G.},
	month = feb,
	year = {2013},
	pmid = {23430651},
	keywords = {AMMA-CATCH, extérieur},
	pages = {940--943},
}

@article{galy-lacaux_long_2009,
	title = {Long term precipitation chemistry and wet deposition in a remote dry savanna site in {Africa} ({Niger})},
	volume = {9},
	issn = {1680-7316},
	doi = {10.5194/acp-9-1579-2009},
	abstract = {Long-term precipitation chemistry have been recorded in the rural area of Banizoumbou (Niger), representative of a semi-arid savanna ecosystem. A total of 305 rainfall samples similar to 90\% of the total annual rainfall) were collected from June 1994 to September 2005. From ionic chromatography, pH major inorganic and organic ions were detected. Rainwater chemistry is controlled by soil/dust emissions associated with terrigeneous elements represented by SO42-, Ca2+, Carbonates, K+ and Mg2+. It is found that calcium and carbonates represent similar to 40\% of the total ionic charge. The second highest contribution is nitrogenous, with annual Volume Weighed Mean (VWM) for NO3- and NH4+ concentrations of 11.6 and 18.1 mu eq.l(-1), respectively. This is the signature of ammonia sources from animals and NOx emissions from savannas soil-particles rain-induced. The mean annual NH3 and NO2 air concentration are of 6 ppbv and 2.6 ppbv, respectively. The annual VWM precipitation concentration of sodium and chloride are both of 8.7 mu eq.l(-1) which reflects the marine signature of monsoonal and humid air masses. The median pH value is of 6.05. Acidity is neutralized by mineral dust, mainly carbonates, and/or dissolved gases such NH3. High level of organic acidity with 8 mu eq.l(-1) and 5.2 mu eq.l(-1) of formate and acetate were also found. The analysis of monthly Black Carbon emissions and Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) values show that both biogenic emission from vegetation and biomass burning could explain the rainfall organic acidity content. The interannual variability of the VWM concentrations around the mean (1994-2005) is between +/- 5\% and +/- 30\% and mainly due to variations of sources strength and rainfall spatio-temporal distribution. From 1994 to 2005, the total mean wet deposition flux in the Sahelian region is of 60.1 mmol. m(-2).yr(-1) +/- 25\%. Finally, Banizoumbou measurements are compared to other long-term measurements of precipitation chemistry in the wet savanna of Lamto (Cote d'Ivoire) and in the forested zone of Zoetele (Cameroon). The total chemical loading presents a maximum in the dry savanna and a minimum in the forest (from 143.7, 100.2 to 86.6 mu eq.l(-1)), associated with the gradient of terrigeneous sources. The wet deposition fluxes present an opposite trend, with 60.0 mmol. m(-2). yr(-1) in Banizoumbou, 108.6 mmol. m(-2). yr(-1) in Lamto and 162.9 mmol. m(-2). yr(-1) in Zoetele, controlled by rainfall gradient along the ecosystems transect.},
	language = {English},
	number = {5},
	journal = {Atmospheric Chemistry and Physics},
	author = {Galy-Lacaux, C. and Laouali, D. and Descroix, L. and Gobron, N. and Liousse, C.},
	year = {2009},
	keywords = {AMMA-CATCH, Niger, Rainfall variability, HYBIS, acetic-acids, aerosol composition, atmospheric deposition, chemical-composition, passive samplers, rainwater chemistry, saharan dust, southern africa, sulfur-dioxide},
	pages = {1579--1595},
}

@article{descloitres_investigation_2013,
	title = {Investigation of groundwater resources in the {Komadugu} {Yobe} {Valley} ({Lake} {Chad} {Basin}, {Niger}) using {MRS} and {TDEM} methods},
	volume = {87},
	issn = {1464-343X},
	doi = {10.1016/j.jafrearsci.2013.07.006},
	abstract = {Groundwater resources quantification and management is a key issue for agricultural development in the Komadugu Yobe (KY) River valley region in the semiarid part of the Lake Chad Basin. To improve the knowledge of available groundwater resources in this poorly-documented area, a geophysical survey across the river valley was conducted near the town of Diffa, southeast Niger. The goal was to estimate the hydrogeological properties of Quaternary formations to a depth of 100 m. Numerical modeling showed that sedimentary deposits composed of thin clayey, loamy, and sandy layers could not be accurately resolved in detail by non-invasive geophysical methods due to the limited spatial resolution of the methods. The use of the Time Domain Electromagnetic (TDEM) method alone was not sufficient to estimate aquifer parameters and the Magnetic Resonance Sounding method (MRS) was used to supplement the geophysical dataset. A twelve kilometer long profile (117 TDEM and 11 MR soundings) was surveyed across the valley to evaluate changes in hydrogeological properties of the Quaternary aquifer from the middle of the river valley to the surrounding sandy plain area. Our results show that the Quaternary aquifer below the KY valley differs from its surroundings and it can be described as follows: (a) the thickness of the KY aquifer ranges from 30 to 60 m and is limited at depth by electrically conductive clay layer, (b) at a depth of similar to 70-80 m, TDEM soundings show a continuous conductive substratum (resistivity is similar to 2 Omega m), attributed to Pliocene clayey formations, (c) the KY valley aquifer may have a larger volume of unconfined groundwater than the surrounding plain aquifer area (MRS water contents of 20-25\% and similar to 15\% respectively), (d) the KY aquifer transmissivity estimated from MRS data is higher than values derived from pumping tests conducted outside the river valley. This study confirms that the Komadugu Yobe valley aquifer represents a significant resource for future agricultural development. In addition, our study shows that the aquifer is not protected by shallow clayey layers; therefore, precautions against contamination should be taken to preserve the quality of this resource. (C) 2013 Elsevier Ltd. All rights reserved.},
	language = {English},
	journal = {Journal of African Earth Sciences},
	author = {Descloitres, M. and Chalikakis, K. and Legchenko, A. and Moussa, A. M. and Genthon, P. and Favreau, G. and Le Coz, M. and Boucher, M. and Oi, M.},
	month = nov,
	year = {2013},
	keywords = {AMMA-CATCH, HYBIS, aquifer characterization, Recharge, Magnetic Resonance Sounding (MRS), Groundwater resources, Komadougou Yobe aquifer, Lake Chad Basin, nuclear-magnetic-resonance, Time Domain Electromagnetism (TDEM), transmissivity},
	pages = {71--85},
}

@article{marteau_onset_2011,
	title = {The onset of the rainy season and farmers’ sowing strategy for pearl millet cultivation in {Southwest} {Niger}},
	volume = {151},
	issn = {0168-1923},
	url = {http://www.sciencedirect.com/science/article/pii/S0168192311001766},
	doi = {10.1016/j.agrformet.2011.05.018},
	abstract = {A multi-year (2004–2009) field survey of on-farm sowing practices in 10 villages located in south-west Niger close to Niamey, is analysed to investigate the relationships (i) between rainfall and the sowing date of pearl millet and the risk of sowing failure, (ii) between sowing and meteorological/agro-climatic onset dates, (iii) between sowing/onset dates, and simulated and observed yield/biomass at the end of the season. Even if some villages sow without any synchronous or anterior rainfall, most parcels (73\% out of the 1551 available cases) are sown during and just after a 2-day wet spell receiving at least 10 mm. In fact, there is a strong correlation (r = 0.82–0.95 depending on onset definition) between the spatial averages of onset and of sowing dates. Most of the failed sowings (≈22\% of total sowings) are related to dry spells lasting at least 7 days after an initial 2-day wet spell receiving less than 10 mm. Simulations with the “Système d’Analyse Régionale des Risques Agronomiques – version Habillée” crop model show that the ideal sowing date, retrospectively computed as the one maximizing simulated yield, is on average about 6 days later than the observed one. Despite the large inter-village variance and the relatively weak inter-annual signal in onset dates and seasonal amounts, there is a tendency for weaker yields and especially weaker amounts of biomass for late onset. But crop simulations show that sowing very early, as for example during or just after the first wet spell when at least 90\% of rainfall stations receive simultaneously at least 1 mm in two consecutive days (i.e. meteorological onset), does not necessarily maximize simulated yield because of the high risk of long-lasting post-onset dry spells. The farmers’ strategy, that is sowing their field during or just after the first significant wet spell, is combined with the use of photoperiodic varieties to provide the best-suited response to the temporal and spatial variability of onset of the rainy season.},
	number = {10},
	urldate = {2014-12-09},
	journal = {Agricultural and Forest Meteorology},
	author = {Marteau, Romain and Sultan, Benjamin and Moron, Vincent and Alhassane, Agali and Baron, Christian and Traoré, Seydou B.},
	month = oct,
	year = {2011},
	keywords = {AMMA-CATCH, Niger, extérieur, grain yield, Farmers’ strategies, Onset date, Pearl millet, Sowing date},
	pages = {1356--1369},
}

@article{malam_abdou_evolution_2015,
	title = {Evolution de la conductivité hydraulique d’un sol sableux cultivé dans l’{Ouest} du {Niger}},
	volume = {19},
	url = {http://www.pressesagro.be/base/index.php/base/article/view/1261},
	doi = {pas de doi},
	language = {Français},
	number = {3},
	journal = {Biotechnologie, Agronomie, Société et Environnement (BASE)},
	author = {Malam Abdou, M. and Vandervaere, J-P. and Descroix, L. and Bouzou Moussa, I. and Faran Maiga, O. and Abdou, S. and Bodo Seyni, B. and Ousseini Daouda, L.},
	year = {2015},
	keywords = {AMMA-CATCH, Niger, HYBIS, PHYREV},
	pages = {270--280},
}

@article{de_jeu_spatially_2014,
	series = {Determination of soil moisture: {Measurements} and theoretical approaches},
	title = {A spatially coherent global soil moisture product with improved temporal resolution},
	volume = {516},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/pii/S0022169414001139},
	doi = {10.1016/j.jhydrol.2014.02.015},
	abstract = {Summary Global soil moisture products that are completely independent of any type of ancillary data and solely rely on satellite observations are presented. Additionally, we further develop an existing downscaling technique that enhances the spatial resolution of such products to approximately 11 km. These products are based on internal modules of the Land Parameter Retrieval Model (LPRM), an algorithm that uses the radiative transfer equation to link soil moisture, vegetation optical depth and land surface temperature to observed brightness temperatures. The soil moisture product that is independent of any type of ancillary data uses the internally calculated dielectric constant as a soil moisture proxy. This data product is not influenced by errors associated with coarse-scale global soil property maps or by any other type of forcing (e.g. re-analysis) data and is therefore solely based on satellite microwave observations. The second step builds upon recent developments to increase the spatial resolution of the LPRM retrievals using a smoothing filter downscaling method. With this method we can attain a spatial resolution that can be more useful at the scale of local and regional hydrological studies as well. The steps presented in this paper were applied to observations from the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E). The newly derived data sets were validated using ground-based observations from the International Soil Moisture Network (ISMN). The internally calculated dielectric constant product results in significantly more days with valid retrievals than the original soil moisture data products, in particular over arid regions. The dielectric constant product resulted in similar correlations with in situ data as the original soil moisture data product. Together, these findings demonstrate the usefulness of this new dielectric constant product for the hydrological modeling community and climate studies. A case study on the Australian Fitzroy catchment demonstrated that the downscaled data product has a more detailed spatial description of soil moisture, especially during wet and dry conditions with more pronounced dry and wet regions within the catchment. The increased resolution data products could therefore improve runoff predictions and this study demonstrated the potential added value of a transitioning from a spatial resolution of 56 km toward a higher resolution of 11 km. The hydrological implications of these newly developed data records are not only linked to AMSR-E satellite data, but also to the next generation Soil Moisture Active and Passive (SMAP) mission where a 9 km spatial resolution is the target resolution for satellite soil moisture products. The new data products will not replace the current LPRM products, but will be added to the existing array of data products and will become publicly available through our data portals.},
	urldate = {2014-12-11},
	journal = {Journal of Hydrology},
	author = {de Jeu, Richard A. M. and Holmes, Thomas R. H. and Parinussa, Robert M. and Owe, Manfred},
	month = aug,
	year = {2014},
	keywords = {remote sensing, Soil moisture, AMMA-CATCH, extérieur, Dielectric constant, no citation, Passive microwave radiometry},
	pages = {284--296},
}

@article{panthou_pointwise_2013,
	title = {From pointwise testing to a regional vision: {An} integrated statistical approach to detect nonstationarity in extreme daily rainfall. {Application} to the {Sahelian} region},
	volume = {118},
	issn = {2169-897X},
	shorttitle = {From pointwise testing to a regional vision},
	doi = {10.1002/jgrd.50340},
	abstract = {Global warming is expected to intensify the hydrologic cycle. Documenting whether significant changes in the extreme precipitation regimes have already happened is consequently one of the challenging topics in climatic research. The high natural variability of extreme precipitation often prevents from obtaining significant results when testing changes in the empirical distribution of extreme rainfall at regional scale. A regional integrated approach is proposed here as one possible answer to this complex methodological problem. Three methods are combined in order to detect regionally significant trends and/or breakpoints in series of annual maximum daily rainfall: (1) individual stationarity tests applied to the raw point series of maxima, (2) a maximum likelihood testing of time-dependent generalized extreme value (GEV) distributions fitted to these series, and (3) a heuristic testing of a regional time-dependent GEV distribution. This approach is applied to a set of 126 daily rain gauges covering the Sahel over the period 1950-1990. It is found that only a few stations are tested as nonstationary when applying classical tests on the raw series, while the two GEV-based models converge to show that the extreme rainfall series indeed underwent a negative breakpoint around 1970. The study evidences the limits of the widely used classical stationarity tests to detect trends in noisy series affected by sampling uncertainties, while using a parametric space and time-dependent GEV efficiently reduces this effect. Showing that the great Sahelian drought was accompanied by a significant decrease of extreme rainfall events is the other main result of this study.},
	language = {English},
	number = {15},
	journal = {Journal of Geophysical Research-Atmospheres},
	author = {Panthou, Geremy and Vischel, Theo and Lebel, Thierry and Quantin, Guillaume and Pugin, Anne-Catherine Favre and Blanchet, Juliette and Ali, Abdou},
	month = aug,
	year = {2013},
	keywords = {Sahel, AMMA-CATCH, HYBIS, west-africa, gev, break-point tests, daily climate extremes, daily temperature, discharge series, extreme daily rainfall, hydrological cycle, intense precipitation, non-stationarity, precipitation extremes, return levels, snow depth, time-series, trends},
	pages = {8222--8237},
}

@article{fontaine_recent_2011,
	title = {Recent changes in precipitation, {ITCZ} convection and northern tropical circulation over {North} {Africa} (1979–2007)},
	volume = {31},
	copyright = {Copyright © 2010 Royal Meteorological Society},
	issn = {1097-0088},
	url = {http://onlinelibrary.wiley.com.biblioplanets.gate.inist.fr/doi/10.1002/joc.2108/abstract},
	doi = {10.1002/joc.2108},
	abstract = {This article focuses on some recent changes observed in the Tropics with special emphasis on the African monsoon region using high-resolution gridded precipitation from the Climatic Research Unit (period 1979–2002), outgoing longwave radiation at the top of the atmosphere from the National Oceanic and Atmospheric Administration and atmospheric reanalyses from the Climate Prediction Center (NCEP-DOE2, period 1979–2007). The results show a rainfall increase in North Africa since the mid-90s with significant northward migrations of rainfall amounts, i.e. + 1.5° for the 400 mm July to September isohyets, whereas deep convection has significantly increased and shifted northward. The subsidence branch of the northern meridional overturning has also been reinforced and shifted by 1° latitude northward in winter. At larger scale, an unambiguous reorganisation of the circulation with increasing subsidence in high troposphere over the Mediterranean and increasing ascendance in the African Intertropical Convergence Zone in northern summer has been noticed in the meridional cell overturning. After 1993–1994, the migration of the Saharan heat low towards northwest has been more marked (+1° to + 2° in latitude; − 1° to − 2° in longitude), whereas its centre intensified at the peak of the tropical rainy season (+10 gpm thickness in the 700–925 hPa layer). These changes are associated with significant reinforcements of the southwesterly low-level winds and Tropical Easterly jet and with a northward shift of the African Easterly jet. Analyses of Global Circulation Model outputs issued from Intergovernmental Panel on Climate Change (A1B scenario and from forced experiments on the ARPEGE-climat (Action de Recherche Petite Echelle Grande Echelle) and Atmospheric Global Circulation Model show that at least part of these changes could be due to the recent warming observed in the Mediterranean/Saharan region. Copyright © 2010 Royal Meteorological Society},
	language = {en},
	number = {5},
	urldate = {2014-12-09},
	journal = {International Journal of Climatology},
	author = {Fontaine, Bernard and Roucou, Pascal and Gaetani, Marco and Marteau, Romain},
	month = apr,
	year = {2011},
	keywords = {West Africa, Precipitation, AMMA-CATCH, climate change, extérieur, monsoon circulation},
	pages = {633--648},
}

@article{pellarin_soil_2010,
	title = {Soil moisture mapping over {West} {Africa}},
	issn = {0018-6368},
	doi = {10.1051/lhb:2010026},
	abstract = {This paper provides an original and simple methodology to map surface soil moisture with a fine temporal and spatial resolution over large areas based on the use of a satellite-based rainfall accumulation product and soil microwave emission measurements at C-band. The first motivation of this study was to obtain high temporal frequency (15 or 30 minutes) in order to study the possible feedback mechanisms between soil moisture and convection in West Africa. The use of satellite measurements exclusively was not possible. A rainfall accumulation product based on MSG satellite measurements was used together with a simple Antecedent Precipitation Index (API) model to produce soil moisture map at the 10 x 10 km(2) and 15 minutes resolution. Due to uncertainties on the satellite-based rainfall accumulation product, derived soil moisture maps were found to be erroneous. An assimilation technique based on AMSR-E C-band measurements and a microwave emission model was developed. The assimilation technique described in this study consists on simulating brightness temperatures (TB) in agreement with observed TB by adjusting the rainfall accumulation estimate between two successive AMSR-E TB measurements. The initial rainfall accumulation estimate is modified using a multiplicative factor ranging from 0 to 7. The best solution is given by the rainfall rate which minimizes the difference between observed and simulated TB. Ground-based soil moisture measurements obtained at three sites in Niger, Mali and Benin were used to assess the methodology. The methodology was found to improve the soil moisture estimates over the three sites.},
	language = {French},
	number = {2},
	journal = {Houille Blanche-Revue Internationale De L Eau},
	author = {Pellarin, Thierry and Tran, Truong and Laurent, Jean-Paul and Vischel, Theo},
	year = {2010},
	keywords = {model, AMMA-CATCH, HYBIS, AO},
	pages = {114--119},
}

@article{pfeffer_evaluating_2013,
	title = {Evaluating surface and subsurface water storage variations at small time and space scales from relative gravity measurements in semiarid {Niger}},
	volume = {49},
	issn = {0043-1397},
	doi = {10.1002/wrcr.20235},
	abstract = {The acquisition of reliable data sets representative of hydrological regimes and their variations is a critical concern for water resource assessment. For the subsurface, traditional approaches based on probe measurements, core analysis, and well data can be laborious, expensive, and highly intrusive, while only yielding sparse data sets. For this study, an innovative field survey, merging relative microgravimetry, magnetic resonance soundings, and hydrological measurements, was conducted to evaluate both surface and subsurface water storage variations in a semiarid Sahelian area. The instrumental setup was implemented in the lower part of a typical hillslope feeding to a temporary pond. Weekly measurements were carried out using relative spring gravimeters during 3 months of the rainy season in 2009 over a 350 x 500 m(2) network of 12 microgravity stations. Gravity variations of small to medium amplitude {\textbackslash}textless= 220 nm s(-2)) were measured with accuracies better than 50 nm s(-2), revealing significant variations of the water storage at small time (from 1 week up to 3 months) and space (from a couple of meters up to a few hundred meters) scales. Consistent spatial organization of the water storage variations were detected, suggesting high infiltration at the outlet of a small gully. The comparison with hydrological measurements and magnetic resonance soundings involved that most of the microgravity variations came from the heterogeneity in the vadose zone. The results highlight the potential of time lapse microgravity surveys for detecting intraseasonal water storage variations and providing rich space-time data sets for process investigation or hydrological model calibration/evaluation.},
	language = {English},
	number = {6},
	journal = {Water Resources Research},
	author = {Pfeffer, Julia and Champollion, Cedric and Favreau, Guillaume and Cappelaere, Bernard and Hinderer, Jacques and Boucher, Marie and Nazoumou, Yahaya and Oi, Monique and Mouyen, Maxime and Henri, Christopher and Le Moigne, Nicolas and Deroussi, Sebastien and Demarty, Jerome and Boulain, Nicolas and Benarrosh, Nathalie and Robert, Olivier},
	month = jun,
	year = {2013},
	keywords = {model, AMMA-CATCH, HYBIS, aquifer characterization, endoreic catchment, hydrologic process simulation, sahelian west niger, Vegetation, Recharge, Semiarid, balance, Groundwater, magnetic resonance soundings, microgravimetry, runoff generation, superconducting gravimeter, surface water, Vadose zone},
	pages = {3276--3291},
}

@article{marshall_improving_2013,
	title = {Improving operational land surface model canopy evapotranspiration in {Africa} using a direct remote sensing approach},
	volume = {17},
	issn = {1027-5606},
	doi = {10.5194/hess-17-1079-2013},
	abstract = {Climate change is expected to have the greatest impact on the world's economically poor. In the Sahel, a climatically sensitive region where rain-fed agriculture is the primary livelihood, expected decreases in water supply will increase food insecurity. Studies on climate change and the intensification of the water cycle in sub-Saharan Africa are few. This is due in part to poor calibration of modeled evapotranspiration (ET), a key input in continental-scale hydrologic models. In this study, a remote sensing model of transpiration (the primary component of ET), driven by a time series of vegetation indices, was used to substitute transpiration from the Global Land Data Assimilation System realization of the National Centers for Environmental Prediction, Oregon State University, Air Force, and Hydrology Research Laboratory at National Weather Service Land Surface Model (GNOAH) to improve total ET model estimates for monitoring purposes in sub-Saharan Africa. The performance of the hybrid model was compared against GNOAH ET and the remote sensing method using eight eddy flux towers representing major biomes of sub-Saharan Africa. The greatest improvements in model performance were at humid sites with dense vegetation, while performance at semi-arid sites was poor, but better than the models before hybridization. The reduction in errors using the hybrid model can be attributed to the integration of a simple canopy scheme that depends primarily on low bias surface climate reanalysis data and is driven primarily by a time series of vegetation indices.},
	language = {English},
	number = {3},
	journal = {Hydrology and Earth System Sciences},
	author = {Marshall, M. and Tu, K. and Funk, C. and Michaelsen, J. and Williams, P. and Williams, C. and Ardo, J. and Boucher, M. and Cappelaere, B. and de Grandcourt, A. and Nickless, A. and Nouvellon, Y. and Scholes, R. and Kutsch, W.},
	year = {2013},
	keywords = {photosynthesis, Data assimilation, Evaporation, MODIS, AMMA-CATCH, HYBIS, savanna, system, use efficiency, Algorithm, atmosphere water flux, semiarid environments},
	pages = {1079--1091},
}

@article{roehrig_present_2013,
	title = {The {Present} and {Future} of the {West} {African} {Monsoon}: {A} {Process}-{Oriented} {Assessment} of {CMIP5} {Simulations} along the {AMMA} {Transect}},
	volume = {26},
	issn = {0894-8755},
	shorttitle = {The {Present} and {Future} of the {West} {African} {Monsoon}},
	url = {http://journals.ametsoc.org.biblioplanets.gate.inist.fr/doi/full/10.1175/JCLI-D-12-00505.1},
	doi = {10.1175/JCLI-D-12-00505.1},
	abstract = {AbstractThe present assessment of the West African monsoon in the models of the Coupled Model Intercomparison Project (CMIP) phase 5 (CMIP5) indicates little evolution since the third phase of CMIP (CMIP3) in terms of both biases in present-day climate and climate projections.The outlook for precipitation in twenty-first-century coupled simulations exhibits opposite responses between the westernmost and eastern Sahel. The spread in the trend amplitude, however, remains large in both regions. Besides, although all models predict a spring and summer warming of the Sahel that is 10\%–50\% larger than the global warming, their temperature response ranges from 0 to 7 K.CMIP5 coupled models underestimate the monsoon decadal variability, but SST-imposed simulations succeed in capturing the recent partial recovery of monsoon rainfall. Coupled models still display major SST biases in the equatorial Atlantic, inducing a systematic southward shift of the monsoon. Because of these strong biases, the monsoon is further evaluated in SST-imposed simulations along the 10°W–10°E African Monsoon Multidisciplinary Analysis (AMMA) transect, across a range of time scales ranging from seasonal to intraseasonal and diurnal fluctuations.The comprehensive set of observational data now available allows an in-depth evaluation of the monsoon across those scales, especially through the use of high-frequency outputs provided by some CMIP5 models at selected sites along the AMMA transect. Most models capture many features of the African monsoon with varying degrees of accuracy. In particular, the simulation of the top-of-atmosphere and surface energy balances, in relation with the cloud cover, and the intermittence and diurnal cycle of precipitation demand further work to achieve a reasonable realism.},
	number = {17},
	urldate = {2014-12-09},
	journal = {Journal of Climate},
	author = {Roehrig, Romain and Bouniol, Dominique and Guichard, Francoise and Hourdin, Frédéric and Redelsperger, Jean-Luc},
	month = mar,
	year = {2013},
	keywords = {Africa, Diurnal effects, Model evaluation/performance, AMMA-CATCH, extérieur, trends, Climate models, intraseasonal variability},
	pages = {6471--6505},
}

@article{gosset_evaluation_2013,
	title = {Evaluation of several rainfall products used for hydrological applications over {West} {Africa} using two high-resolution gauge networks},
	volume = {139},
	issn = {0035-9009},
	doi = {10.1002/qj.2130},
	abstract = {The evaluation of rainfall products over the West African region will be an important component of the Megha-Tropiques (MT) Ground Validation (GV) plan. In this paper, two dense research gauge networks from Benin and Niger, integrated in the MT GV plan, are presented and are used to evaluate several currently available global or regional satellite-based rainfall products. Eight productsthe Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN), Climate Prediction Center Morphing method (CMORPH), Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA) 3B42 real-time and gauge-adjusted version, Global Satellite Mapping of Precipitation (GSMaP), Climate Prediction Center (CPC) African Rainfall Estimate (RFE), Estimation des Precipitation par SATellite (EPSAT), and Global Precipitation Climatology Project One Degree Daily estimate (GPCP-1DD)are compared to the ground reference. The comparisons are carried out at daily, 1 degrees resolution, over the rainy season (June-September), between the years 2003 and 2010. The work focuses on the ability of the various products to reproduce salient features of the rainfall regime that impact the hydrological response. The products are analysed on a multi-criteria basis, focusing in particular on the way they distribute the rainfall within the season and by rain rate class. Standard statistical diagnoses such as the correlation coefficient, bias, root mean square error and Nash skill score are computed and the inter-annual variability is documented. Two simplified hydrological models are used to illustrate how the nature and structure of the product error impact the model output in terms of runoff (calculated using the Soil Conservation Service method, SCS, in Niger) or outflow (calculated with the modele du Genie Rural a 4 parametres Journalier', GR4J model, in Benin). Copyright (c) 2013 Royal Meteorological Society},
	language = {English},
	number = {673},
	journal = {Quarterly Journal of the Royal Meteorological Society},
	author = {Gosset, Marielle and Viarre, Julien and Quantin, Guillaume and Alcoba, Matias},
	month = apr,
	year = {2013},
	keywords = {validation, Sahel, Hydrology, Runoff, AMMA-CATCH, Niger, HYBIS, benin, variability, scales, water-balance, global precipitation, part ii, passive microwave, precipitation analysis tmpa, quantitative rainfall estimates (QPE), satellite rainfall estimates, trmm},
	pages = {923--940},
}

@article{lee_inversion_2014,
	title = {Inversion of soil hydraulic properties from the {DEnKF} analysis of {SMOS} soil moisture over {West} {Africa}},
	volume = {188},
	issn = {0168-1923},
	doi = {10.1016/j.agrformet.2013.12.009},
	abstract = {The application of Soil-Vegetation-Atmosphere-Transfer (SVAT) scheme into the estimation of soil moisture profile in semi-arid regions is largely constrained by a scarcity of spatially distributed soil and hydraulic property information. Especially, on a large scale in very dry and sandy soils or other extreme conditions, it is difficult to accurately map soil and hydraulic properties with soil maps-based Pedo-Transfer Functions (PTFs), because PTFs are usually semi-empirically defined for specific sites. One strategy to overcome this limitation is to employ satellite data for a purpose of calibration. This paper provides an operational framework of inverting the SVAT soil hydraulic variables from the deterministic ensemble Kalman filter (DEnKF) analysis of Soil Moisture and Ocean Salinity (SMOS) surface soil moisture product. This inverse calibration was first verified with the Analyses Multidisciplinaires de la Mousson Africaine (AMMA) super site data representative of a single grid cell (0.25 degrees) of satellite data. At this local scale, the results demonstrated that the mis-estimation problems of soil surface variable C-1 and equilibrium soil moisture theta(geq) were successfully solved after calibration, demonstrating a better agreement with the field measurement of soil moisture profile than the SMOS product and un-calibrated SVAT scheme using soil maps-based PTFs. On the meso scale, the calibrated SVAT scheme using inverted surface variables appropriately captured a non-linear relationship between surface and root zone soil moisture by showing a typical soil moisture profile in dry climates, where dry surface soil moisture is spatially consistent with rainfall events, but wet root zone soil moisture shows low correlations with surface soil moisture distributions and rainfall events. In contrast, the un-calibrated SVAT scheme using soil maps-based PTFs significantly overestimated surface soil moisture and rainfall effect. This approach suggests several operational merits in that there is no need to heavily rely on empirically defined PTFs or recalibrate land surface parameters for different land surface conditions, and this can be applied even when parameter measurements are unavailable or highly uncertain. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.},
	language = {English},
	journal = {Agricultural and Forest Meteorology},
	author = {Lee, J. H. and Pellarin, T. and Kerr, Y. H.},
	month = may,
	year = {2014},
	keywords = {Data assimilation, AMMA-CATCH, simulation, HYBIS, PHYREV, Temperature, calibration, ensemble kalman filter, land-surface processes, DEnKF, ISBA land surface parameterization, l-band, microwave emission, Parameter inversion, parameter-estimation, SMOS surface soil moisture, Soil and hydraulic property in semi-arid regions, SVAT model, svat-model},
	pages = {76--88},
}

@article{pellarin_simple_2013,
	title = {A simple and effective method for correcting soil moisture and precipitation estimates using {AMSR}-{E} measurements},
	volume = {136},
	issn = {0034-4257},
	doi = {10.1016/j.rse.2013.04.011},
	abstract = {Recent studies have demonstrated the possibility to use surface soil moisture satellite products in order to correct precipitation estimates. The overall approaches are generally based on adjusting the precipitation rate into a water balance model in order to match observed and simulated soil moisture. In the present study, a recently proposed approach was improved and assessed over a 4-year period in West Africa. Three different satellite precipitation products (CMORPH, TRMM-3B42 and PERSIANN) were used in this study. The new algorithm was evaluated over three 0.25 x 0.25 degrees areas in Niger, Mali and Benin and precipitation estimates (before and after correction) were compared to observed ground-based precipitation measurements. An assessment was also conducted at the regional scale using 48 independent rainfall stations located in Togo, Niger and Burkina Faso. The proposed methodology showed that, after correction, the three satellite precipitation products converge to the ground-based precipitation measurements, demonstrating the robustness of the methodology. In addition, soil moisture estimates derived from the methodology were found to be in good agreement with ground-based soil moisture measurements (R-2 {\textbackslash}textgreater 0.78 in Niger, R-2 {\textbackslash}textgreater 0.54 in Mali and R-2 {\textbackslash}textgreater 0.64 in Benin). (C) 2013 Elsevier Inc. All rights reserved.},
	language = {English},
	journal = {Remote Sensing of Environment},
	author = {Pellarin, Thierry and Louvet, Samuel and Gruhier, Claire and Quantin, Guillaume and Legout, Cedric},
	month = sep,
	year = {2013},
	keywords = {West Africa, Soil moisture, models, rainfall, AMMA-CATCH, HYBIS, AO, AMSR-E, brightness temperatures, simple parameterization, land, Algorithm, band microwave emission, global simulation, Satellite precipitation, temporal resolution},
	pages = {28--36},
}

@article{borbon_transport_2012,
	title = {Transport and chemistry of formaldehyde by mesoscale convective systems in {West} {Africa} during {AMMA} 2006},
	volume = {117},
	copyright = {©2012. American Geophysical Union. All Rights Reserved.},
	issn = {2156-2202},
	url = {http://onlinelibrary.wiley.com/doi/10.1029/2011JD017121/abstract},
	doi = {10.1029/2011JD017121},
	abstract = {In situ measurements of formaldehyde (CH2O) onboard four European research aircraft in August 2006 as part of the African Monsoon Multidisciplinary Analysis (AMMA) experiment in West Africa are used (1) to examine the redistribution of CH2O by mesoscale convective systems (MCS) in the tropical upper troposphere (UT), (2) to evaluate the scavenging efficiency (SE) of CH2O by MCS and (3) to quantify the impact of CH2O on UT photooxidant production downwind of MCS. The intercomparison of CH2O measurements is first tested, providing a unique and consistent 3-D-spatially resolved CH2O database in background and convective conditions. While carbon monoxide (CO) is vertically uplifted by deep convection up to 12 km, CH2O is also affected by cloud processing as seen from its ratio relative to CO with altitude. A new observation-based model is established to quantify the SE of CH2O. This model shows that convective entrainment of free tropospheric air cannot be neglected since it contributes to 40\% of the convective UT air. For the 4 studied MCS, SE shows a large variability within a 4\% to 39\% range at a relative standard deviation of 30\%, which is consistent with MCS features. A time-dependent photochemical box model is applied to convective UT air. After convection, 60\% of CH2O is due to its photochemical production rather than to its direct transport. Model results indicate that CH2O directly injected by convection does not impact ozone and HOx production in the tropical UT of West Africa. NOx and anthropogenic hydrocarbon precursors dominate the secondary production of CH2O, ozone and HOx.},
	language = {en},
	number = {D12},
	urldate = {2014-12-09},
	journal = {Journal of Geophysical Research: Atmospheres},
	author = {Borbon, Agnès and Ruiz, M. and Bechara, J. and Aumont, B. and Chong, M. and Huntrieser, H. and Mari, C. and Reeves, C. E. and Scialom, Georges and Hamburger, T. and Stark, H. and Afif, C. and Jambert, C. and Mills, G. and Schlager, H. and Perros, P. E.},
	month = jun,
	year = {2012},
	keywords = {West Africa, AMMA-CATCH, extérieur, chemistry, cloud uptake, deep convection, formaldehyde, tropical upper troposphere},
	pages = {D12301},
}

@article{schrodt_foliar_2015,
	title = {Foliar trait contrasts between {African} forest and savanna trees: genetic versus environmental effects},
	volume = {42},
	issn = {1445-4408},
	shorttitle = {Foliar trait contrasts between {African} forest and savanna trees},
	url = {http://www.publish.csiro.au/?paper=FP14040},
	doi = {10.1071/FP14040},
	language = {en},
	number = {1},
	urldate = {2015-03-06},
	journal = {Functional Plant Biology},
	author = {Schrodt, Franziska and Domingues, Tomas F. and Feldpausch, Ted R. and Saiz, Gustavo and Quesada, Carlos Alberto and Schwarz, Michael and Ishida, F. Yoko and Compaore, Halidou and Diallo, Adamo and Djagbletey, Gloria and Hien, Fidele and Sonké, Bonaventure and Toedoumg, Herman and Zapfack, Loius and Hiernaux, Pierre and Mougin, Eric and Bird, Michael. I. and Grace, John and Lewis, Simon L. and Veenendaal, Elmar M. and Lloyd, Jon},
	year = {2015},
	keywords = {Sahel, AMMA-CATCH, ext1, AO},
	pages = {63},
}

@article{de_rosnay_amma_2009,
	title = {{AMMA} {Land} {Surface} {Model} {Intercomparison} {Experiment} coupled to the {Community} {Microwave} {Emission} {Model}: {ALMIP}-{MEM}},
	volume = {114},
	issn = {2169-897X},
	shorttitle = {{AMMA} {Land} {Surface} {Model} {Intercomparison} {Experiment} coupled to the {Community} {Microwave} {Emission} {Model}},
	url = {http://www.cnrm-game-meteo.fr/amma-moana/amma_surf/almip/},
	doi = {10.1029/2008JD010724},
	abstract = {This paper presents the African Monsoon Multidisciplinary Analysis (AMMA) Land Surface Models Intercomparison Project (ALMIP) for Microwave Emission Models (ALMIP-MEM). ALMIP-MEM comprises an ensemble of simulations of C-band brightness temperatures over West Africa for 2006. Simulations have been performed for an incidence angle of 55 degrees, and results are evaluated against C-band satellite data from the Advanced Microwave Scanning Radiometer on Earth Observing System (AMSR-E). The ensemble encompasses 96 simulations, for 8 Land Surface Models (LSMs) coupled to 12 configurations of the Community Microwave Emission Model (CMEM). CMEM has a modular structure which permits combination of several parameterizations with different vegetation opacity and soil dielectric models. ALMIP-MEM provides the first intercomparison of state-of-theart land surface and microwave emission models at regional scale. Quantitative estimates of the relative importance of land surface modeling and radiative transfer modeling for the monitoring of low-frequency passive microwave emission on land surfaces are obtained. This is of high interest for the various users of coupled land surface microwave emission models. Results show that both LSMs and microwave model components strongly influence the simulated top of atmosphere (TOA) brightness temperatures. For most of the LSMs, the Kirdyashev opacity model is the most suitable to simulate TOA brightness temperature in best agreement with the AMSR-E data. When this best microwave modeling configuration is used, all the LSMs are able to reproduce the main temporal and spatial variability of measured brightness temperature. Averaged among the LSMs, correlation is 0.67 and averaged normalized standard deviation is 0.98.},
	language = {English},
	journal = {Journal of Geophysical Research-Atmospheres},
	author = {de Rosnay, P. and Drusch, M. and Boone, A. and Balsamo, G. and Decharme, B. and Harris, P. and Kerr, Y. and Pellarin, T. and Polcher, J. and Wigneron, J.-P.},
	month = mar,
	year = {2009},
	keywords = {AMMA-CATCH, HYBIS, AO, AMSR-E, brightness temperatures, soil-moisture retrieval, African monsoon, global simulation, crop fields, dielectric model, parameterization schemes, plains hydrology experiment, radiofrequency interference},
	pages = {D05108},
}

@article{gaudart_modelling_2009,
	title = {Modelling malaria incidence with environmental dependency in a locality of {Sudanese} savannah area, {Mali}},
	volume = {8},
	issn = {1475-2875},
	doi = {10.1186/1475-2875-8-61},
	abstract = {Background: The risk of Plasmodium falciparum infection is variable over space and time and this variability is related to environmental variability. Environmental factors affect the biological cycle of both vector and parasite. Despite this strong relationship, environmental effects have rarely been included in malaria transmission models. Remote sensing data on environment were incorporated into a temporal model of the transmission, to forecast the evolution of malaria epidemiology, in a locality of Sudanese savannah area. Methods: A dynamic cohort was constituted in June 1996 and followed up until June 2001 in the locality of Bancoumana, Mali. The 15-day composite vegetation index (NDVI), issued from satellite imagery series (NOAA) from July 1981 to December 2006, was used as remote sensing data. The statistical relationship between NDVI and incidence of P. falciparum infection was assessed by ARIMA analysis. ROC analysis provided an NDVI value for the prediction of an increase in incidence of parasitaemia. Malaria transmission was modelled using an SIRS-type model, adapted to Bancoumana's data. Environmental factors influenced vector mortality and aggressiveness, as well as length of the gonotrophic cycle. NDVI observations from 1981 to 2001 were used for the simulation of the extrinsic variable of a hidden Markov chain model. Observations from 2002 to 2006 served as external validation. Results: The seasonal pattern of P. falciparum incidence was significantly explained by NDVI, with a delay of 15 days (p = 0.001). An NDVI threshold of 0.361 (p = 0.007) provided a Diagnostic Odd Ratio (DOR) of 2.64 (CI95\% [1.26;5.52]). The deterministic transmission model, with stochastic environmental factor, predicted an endemoepidemic pattern of malaria infection. The incidences of parasitaemia were adequately modelled, using the observed NDVI as well as the NDVI simulations. Transmission pattern have been modelled and observed values were adequately predicted. The error parameters have shown the smallest values for a monthly model of environmental changes. Conclusion: Remote-sensed data were coupled with field study data in order to drive a malaria transmission model. Several studies have shown that the NDVI presents significant correlations with climate variables, such as precipitations particularly in Sudanese savannah environments. Nonlinear model combining environmental variables, predisposition factors and transmission pattern can be used for community level risk evaluation.},
	language = {English},
	journal = {Malaria Journal},
	author = {Gaudart, Jean and Toure, Ousmane and Dessay, Nadine and Dicko, A. Lassane and Ranque, Stephane and Forest, Loic and Demongeot, Jacques and Doumbo, Ogobara K.},
	month = apr,
	year = {2009},
	keywords = {climate, AMMA-CATCH, Mali, extérieur, HYBIS, satellite data, remotely-sensed data, difference vegetation index, hidden markov-models, high-resolution radiometer, land-cover classification, ndvi data set, probabilistic functions, transmission},
	pages = {61},
}

@article{gerbaux_sensitivity_2009,
	title = {The sensitivity of {Sahelian} runoff to climate change},
	volume = {54},
	issn = {0262-6667},
	doi = {10.1623/hysj.54.1.5},
	abstract = {A simple method is used to study the response of runoff in the Sahel to climate change. The statistical characteristics of rainfall are calculated over the western part of the Sahel for the period 1961-1990, using the BADOPLU network. Daily rainfall is simulated using a Markov process with Weibull distribution for rainfall depths. Runoff is modelled using a conceptual SCS model and the curve numbers are calculated for West Africa. Climate change is provided by simulations using the Arpege GCM (Scenario A1B), and a perturbation method is used on the parameters which describe the rainfall. Changes in rainfall are assumed to occur through increases in frequency, not intensity. Using Arpege, runoff is mainly found to increase, in depth and in number of events, by the end of the 21st century. Changes in evaporation and land use are not included in the analysis. The impact of this 21st century potential climate change (rainfall) on the runoff is found to be of the same magnitude as the impact of changes in land use.},
	language = {English},
	number = {1},
	journal = {Hydrological Sciences Journal-Journal Des Sciences Hydrologiques},
	author = {Gerbaux, Martin and Hall, Nick and Dessay, Nadine and Zin, Isabella},
	month = feb,
	year = {2009},
	keywords = {AMMA-CATCH, scale, HYBIS, AO, variability, impact, west niger, catchment, disaggregation, Arpege GCM, BADOPLU network, curve number, Markov chain, rainfall statistics, Sahelian runoff, SCS model},
	pages = {5--16},
}

@article{guilloteau_impacts_2014,
	title = {Impacts of {Satellite}-{Based} {Rainfall} {Products} on {Predicting} {Spatial} {Patterns} of {Rift} {Valley} {Fever} {Vectors}},
	volume = {15},
	issn = {1525-755X},
	url = {http://journals.ametsoc.org.biblioplanets.gate.inist.fr/doi/full/10.1175/JHM-D-13-0134.1},
	doi = {10.1175/JHM-D-13-0134.1},
	abstract = {AbstractSpatiotemporal rainfall variability is a key parameter controlling the dynamics of mosquitoes/vector-borne diseases such as malaria, Rift Valley fever (RVF), or dengue. Impacts from rainfall heterogeneity at small scales (i.e., 1–10 km) on the risk of epidemics (i.e., host bite rate or number of bites per host and per night) must be thoroughly evaluated. A model with hydrological and entomological components for risk prediction of the RVF zoonosis is proposed. The model predicts the production of two mosquito species within a 45 km × 45 km area in the Ferlo region, Senegal. The three necessary steps include 1) best rainfall estimation on a small scale, 2) adequate forcing of a simple hydrological model leading to pond dynamics (ponds are the primary larvae breeding grounds), and 3) best estimate of mosquito life cycles obtained from the coupled entomological model. The sensitivity of the model to the spatiotemporal heterogeneity of rainfall is first tested using high-resolution rain fields from a weather radar. The need for high-resolution rain data is thus demonstrated. Several high-resolution satellite rainfall products are evaluated in the region of interest using a dense rain gauge network. Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis 3B42, version 6 (TMPA-3B42V6), and 3B42 in real time (TMPA-3B42RT); Global Satellite Mapping of Precipitation (GSMaP) in near–real time (GSMaP-NRT) and Moving Vector with Kalman version (GSMaP-MVK); African Rainfall Estimation Algorithm, version 2.0 (RFE 2.0); Climate Prediction Center (CPC) morphing technique (CMORPH); and Precipitation Estimation from Remotely Sensed Information Using Artificial Neural Networks (PERSIANN) are tested and finally corrected using a probability matching method. The corrected products are then used as forcing to the coupled model over the 2003–10 period. The predicted number and size of ponds and their dynamics are greatly improved compared to the model forced only by a single gauge. A more realistic spatiotemporal distribution of the host bite rate of the RVF vectors is thus expected.},
	number = {4},
	urldate = {2014-12-09},
	journal = {Journal of Hydrometeorology},
	author = {Guilloteau, Clement and Gosset, Marielle and Vignolles, Cecile and Alcoba, Matias and Tourre, Yves M. and Lacaux, Jean-Pierre},
	month = may,
	year = {2014},
	keywords = {Hydrologic models, rainfall, AMMA-CATCH, Disease, Risk assessment, satellite observations, Tropical variability},
	pages = {1624--1635},
}

@article{kamagate_processus_2007,
	title = {Processus et bilan des flux hydriques d’un bassin versant de milieu tropical de socle au {Bénin} ({Donga}, haut {Ouémé})},
	volume = {339},
	doi = {10.1016/j.crte.2007.04.003},
	journal = {Comptes Rendus Geoscience},
	author = {Kamagaté, B. and Séguis, L. and Favreau, G. and Seidel, J.-L. and Descloitres, M. and Affaton, Pascal},
	year = {2007},
	keywords = {AMMA-CATCH, Benin},
	pages = {418--429},
}

@article{lebel_amma_2010,
	title = {The {AMMA} field campaigns: {Multiscale} and multidisciplinary observations in the {West} {African} region},
	volume = {136},
	issn = {0035-9009},
	shorttitle = {The {AMMA} field campaigns},
	doi = {10.1002/qj.486},
	abstract = {AMMA - the African Monsoon Multidisciplinary Analysis - is the biggest programme of research into environment and climate ever attempted in At AMMA has involved a comprehensive field experiment bringing together ocean. land and atmospheric measurements. on time-scales ranging from hourly and daily variability up to the changes in seasonal activity over a number of years. Many of the publications in this special issue make use of subsets of the AMMA measurements. collected from a diverse set of sensors As a general introduction to the special issue, this paper provides a comprehensive overview of the AMMA observational programme. and summarises the scientific strategy which has defined the field deployment The relationship between the existing observational monitoring networks of the region and the new sensors deployed for AMMA. and for the future, is described Making use of regional and sub-regional maps. the main groups of sensors are described in terms of their deployment periods and then spatial co-ordination The key linkages between different groups of measurements are also outlined. in terms of the strategy for their combined use and in terms of their interdependence Some brief summaries of conditions sampled doling the three years of the AM MA Extended Observing Period are also given Copyright (C) 2009 Royal Meteorological Society and Crown Copyright},
	language = {English},
	journal = {Quarterly Journal of the Royal Meteorological Society},
	author = {Lebel, T. and Parker, D. J. and Flamant, C. and Bourles, B. and Marticorena, B. and Mougin, E. and Peugeot, C. and Diedhiou, A. and Haywood, J. M. and Ngamini, J. B. and Polcher, J. and Redelsperger, J. -L. and Thorncroft, C. D.},
	month = jan,
	year = {2010},
	keywords = {Diurnal cycle, climate, AMMA-CATCH, scale, Rainfall variability, Monsoon, convective system, saharan dust, 3-dimensional structure, aircraft observations, easterly jet, environment, intertropical discontinuity region, monitoring, strategy},
	pages = {8--33},
}

@article{guerin_geophysical_2009,
	title = {Geophysical characterisation of karstic networks - {Application} to the {Ouysse} system ({Poumeyssen}, {France})},
	volume = {341},
	issn = {1631-0713},
	doi = {10.1016/j.crte.2009.08.005},
	abstract = {In the framework of the management of karstic aquifers, geophysical reconnaissance can be used to locate conduits and caves, and to characterise the surrounding limestone matrix. Suitable characterisation of heterogeneities in the karstic environment is, however, challenging for ground-based geophysical methods. The present article describes the results, and evaluates the response and accuracy of combined geophysical measurements carried out at the Poumeyssen test site in France, involving electrical resistivity imaging (ERI), magnetic resonance sounding (MRS), "mise-a-la-masse" electrical mapping, and seismic tomography. This site provides the opportunity to study a relatively wide, shallow, water-filled conduit whose location and shape are known from topographic work carried out by cave divers. Seismic and MRS provided the exact location and width of the conduit, to within a I few meters. The seismic and electrical data suggest that the limestone medium surrounding the conduit is not homogeneous. To cite this article: R. Guerin et al., C. R. Geoscience 341 (2009). (C) 2009 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.},
	language = {English},
	number = {10-11},
	journal = {Comptes Rendus Geoscience},
	author = {Guerin, Roger and Baltassat, Jean-Michel and Boucher, Marie and Chalikakis, Konstantinos and Galibert, Pierre-Yves and Girard, Jean-Francois and Plalgnes, Valerie and Valois, Remi},
	month = nov,
	year = {2009},
	keywords = {AMMA-CATCH, HYBIS, magnetic-resonance, Magnetic Resonance Sounding (MRS), aquifer, conduit, Electrical Resistivity Imaging (ERI), inversion, Karst, Ouysse karstic system, Poumeyssen shaft, resistivity, Seismic tomography},
	pages = {810--817},
}

@article{hernandez-diaz_climate_2013,
	title = {Climate simulation over {CORDEX} {Africa} domain using the fifth-generation {Canadian} {Regional} {Climate} {Model} ({CRCM5})},
	volume = {40},
	issn = {0930-7575, 1432-0894},
	url = {http://link.springer.com/article/10.1007/s00382-012-1387-z},
	doi = {10.1007/s00382-012-1387-z},
	abstract = {The new fifth-generation Regional Climate Model (CRCM5) was driven by ERA reanalyses for the period 1984–2008 over the African continent following the CORDEX experimental protocol. Overall the model succeeds in reproducing the main features of the geographical distribution and seasonal cycle of temperature and precipitation, the diurnal cycle of precipitation, and the West African Monsoon (WAM). Biases in surface temperature and precipitation are discussed in relation with some circulation defects noted in the simulation. In the African regions near the equator, the model successfully reproduces the double peak of rainfall due to the double passage of the tropical rainbelt, although it better simulates the magnitude and timing of the second peak of precipitation. CRCM5 captures the timing of the monsoon onset for the Sahel region but underestimates the magnitude of precipitation. The simulated diurnal cycle is quite well simulated for all of the regions, but is always somewhat in advance for the timing of rainfall peak. In boreal summer the CRCM5 simulation exhibits a weak cold bias over the Sahara and the maximum temperature is located too far south, resulting in a southward bias in the position of the Saharan Heat Low. The region of maximum ascent in the deep meridional circulation of the Hadley cell is well located in the CRCM5 simulation, but it is somewhat too narrow. The core of the African Easterly Jet is of the right strength and almost at the right height, but it is displayed slightly southward, as a consequence of the southward bias in the position of the Saharan Heat Low and the thermal wind relationship. These biases appear to be germane to the WAM rainfall band being narrower and not moving far enough northward, resulting in a dry bias in the Sahel.},
	language = {en},
	number = {5-6},
	urldate = {2014-12-09},
	journal = {Climate Dynamics},
	author = {Hernández-Díaz, Leticia and Laprise, René and Sushama, Laxmi and Martynov, Andrey and Winger, Katja and Dugas, Bernard},
	month = mar,
	year = {2013},
	keywords = {West African monsoon, Africa, AMMA-CATCH, extérieur, CORDEX, Geophysics/Geodesy, Meteorology/Climatology, Oceanography, Regional Climate Modelling},
	pages = {1415--1433},
}

@article{amogu_runoff_2015,
	title = {Runoff evolution due to land use change in a small {Sahelian} catchment},
	volume = {60},
	issn = {0262-6667},
	url = {http://dx.doi.org/10.1080/02626667.2014.885654},
	doi = {10.1080/02626667.2014.885654},
	abstract = {AbstractLand use changes have been significant these last decades in West Africa, particularly in the Sahel region; in this area, climatic and demographic factors have led to a rise in cropped areas in recent decades causing strong changes in the water cycle and in river regimes.This study compares the rainfall-runoff relationships for two periods (1991-1994 and 2004-2011) in two small and similar neighbouring Sahelian catchments (approx 0.1 km² each). This allows highlighting the different hydrological consequences of land use/land cover change, particularly the fallow shortening as well as the consequent degradation of topsoil.The main land surface change is a 75\% increase in crusted soil area. Runoff increased by more than 20\% on average between the two periods while flood durations decreased by 50\% on average. However runoff values remained largely constant in the lower part of the northern basin due to a strong increase in in-channel infiltration.},
	number = {1},
	urldate = {2014-06-02},
	journal = {Hydrological Sciences Journal},
	author = {Amogu, O. and Esteves, M. and Vandervaere, J-P and Malam Abdou, M. and Panthou, G. and Rajot, J-L. and Souley Yéro, K. and Boubkraoui, S. and Lapetite, JM. and Dessay, N. and Zin, I. and Bachir, A. and Bouzou Moussa, I. and Faran Maïga, O. and Gautier, E. and Mamadou, I. and Descroix, L.},
	year = {2015},
	keywords = {AMMA-CATCH, Niger, HYBIS, PHYREV},
	pages = {78--95},
}

@article{fatras_spaceborne_2015,
	title = {Spaceborne altimetry and scatterometry backscattering signatures at {C}- and {Ku}-bands over {West} {Africa}},
	volume = {159},
	issn = {00344257},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425714004891},
	doi = {10.1016/j.rse.2014.12.005},
	language = {en},
	urldate = {2015-03-17},
	journal = {Remote Sensing of Environment},
	author = {Fatras, C. and Frappart, F. and Mougin, E. and Frison, P.-L. and Faye, G. and Borderies, P. and Jarlan, L.},
	month = mar,
	year = {2015},
	keywords = {AMMA-CATCH, ext1, AO, Radar},
	pages = {117--133},
}

@article{manfreda_physically_2014,
	title = {A physically based approach for the estimation of root-zone soil moisture from surface measurements},
	volume = {18},
	issn = {1607-7938},
	url = {http://www.hydrol-earth-syst-sci.net/18/1199/2014/},
	doi = {10.5194/hess-18-1199-2014},
	abstract = {In the present work, we developed a new formulation for the estimation of the soil moisture in the root zone based on the measured value of soil moisture at the surface. It was derived from a simplified soil water balance equation for semiarid environments that provides a closed form of the relationship between the root zone and the surface soil moisture with a limited number of physically consistent parameters. The method sheds lights on the mentioned relationship with possible applications in the use of satellite remote sensing retrievals of soil moisture. The proposed approach was used on soil moisture measurements taken from the African Monsoon Multidisciplinary Analysis (AMMA) and the Soil Climate Analysis Network (SCAN) databases. The AMMA network was designed with the aim to monitor three so-called mesoscale sites (super sites) located in Benin, Mali, and Niger using point measurements at different locations. Thereafter the new formulation was tested on three additional stations of SCAN in the state of New Mexico (US). Both databases are ideal for the application of such method, because they provide a good description of the soil moisture dynamics at the surface and the root zone using probes installed at different depths. The model was first applied with parameters assigned based on the physical characteristics of several sites. These results highlighted the potential of the methodology, providing a good description of the root-zone soil moisture. In the second part of the paper, the model performances were compared with those of the well-known exponential filter. Results show that this new approach provides good performances after calibration with a set of parameters consistent with the physical characteristics of the investigated areas. The limited number of parameters and their physical interpretation makes the procedure appealing for further applications to other regions.},
	number = {3},
	urldate = {2014-12-09},
	journal = {Hydrol. Earth Syst. Sci.},
	author = {Manfreda, S. and Brocca, L. and Moramarco, T. and Melone, F. and Sheffield, J.},
	month = mar,
	year = {2014},
	keywords = {AMMA-CATCH, Benin, Niger, Mali, extérieur, AO, ISMN},
	pages = {1199--1212},
}

@article{issoufou_change_2013,
	title = {Change in water loss regulation after canopy clearcut of a dominant shrub in {Sahelian} agrosystems, {Guiera} senegalensis {J}. {F}. {Gmel}},
	volume = {27},
	issn = {0931-1890, 1432-2285},
	url = {http://link.springer.com/article/10.1007/s00468-013-0852-6},
	doi = {10.1007/s00468-013-0852-6},
	abstract = {This paper analyzes the effect of the canopy age of Guiera senegalensis J.F. Gmel on water regulation processes and adaptative strategy to drought over a period of 2 years. The species is widespread in the agricultural Sahel. Before sowing, farmers cut back the shrubs to limit competition with crops. The stumps resprout after the millet harvest. Leaf water potential and stomatal conductance were measured in two fallows and in the two adjacent cultivated fields. Leaf transpiration rate and soil-to-leaf hydraulic conductance were deduced. The decrease in both stomatal and plant hydraulic conductance caused by seasonal drought was greater in mature shrubs than in current year resprouts. The decrease in predawn and midday leaf water potentials in response to seasonal drought was isohydrodynamic, and it was greater in mature shrubs, suggesting that current year resprouts are under less stress. In resprouts, the leaf transpiration rate stopped increasing beyond a hydraulic conductance threshold of 0.05 mol. m−2 s−1 MPa−1. Vulnerability to cavitation was determined on segments of stems in the laboratory. The leaf water potential value at which stomatal closure occurred was −2.99 ± 0.68 MPa, which corresponded to a 30 \% loss in xylem conductivity. Thanks to its positive safety margin of 0.6 MPa, G. senegalensis can survive above this value. The observed strategy places G. senegalensis among the non-extreme xeric plants, leading us to suppose that this species will be vulnerable to the expected increase in regional drought.},
	language = {en},
	number = {4},
	urldate = {2014-06-05},
	journal = {Trees},
	author = {Issoufou, Hassane Bil-Assanou and Delzon, Sylvain and Laurent, Jean-Paul and Saâdou, Mahamane and Mahamane, Ali and Cappelaere, Bernard and Demarty, Jérôme and Oï, Monique and Rambal, Serge and Seghieri, Josiane},
	month = aug,
	year = {2013},
	keywords = {Agriculture, AMMA-CATCH, adaptation, HYBIS, Embolism, Forestry, Functional limits, Guiera senegalensis, Hydraulic conductance, Plant Anatomy/Development, Plant Pathology, Plant Physiology, Plant Sciences, Transpiration rate},
	pages = {1011--1022},
}

@article{he_diurnal_2014,
	title = {The {Diurnal} {Cycle} of {Precipitation} in {Regional} {Spectral} {Model} {Simulations} over {West} {Africa}: {Sensitivities} to {Resolution} and {Cumulus} {Schemes}},
	issn = {0882-8156},
	shorttitle = {The {Diurnal} {Cycle} of {Precipitation} in {Regional} {Spectral} {Model} {Simulations} over {West} {Africa}},
	url = {http://journals.ametsoc.org/doi/abs/10.1175/WAF-D-14-00013.1},
	doi = {10.1175/WAF-D-14-00013.1},
	abstract = {AbstractAs a basic form of climate patterns, the diurnal cycle of precipitation (DCP) can provide a key test bed for model reliability and development. In this study, DCP over West Africa was simulated by the National Centers for Environmental Prediction (NCEP) Regional Spectral Model (RSM) during the monsoon season (April to September) of 2005. Three convective parameterization schemes (CPSs): single layer Simplified Arakawa-Schubert (SAS), multi-layer Relaxed Arakawa-Schubert (RAS) and new Kain-Fritsch (KF2), were evaluated at two horizontal resolutions (20 km and 10 km). The Benin mesoscale site was singled out for additional investigation of resolution effects. Harmonic analysis was used to characterize the phase and amplitude of DCP. Compared to satellite observations, the overall spatial distribution of amplitude was well captured at regional scales. The RSM properly reproduced the observed late afternoon peak over land and the early morning peak over ocean. Nevertheless, peak time was early. Sensitivity experiments of CPSs showed similar spatial patterns of rainfall totals among the schemes; CPSs mainly affected the amplitude of diurnal cycle, while the phase was not significantly shifted. There is no clear optimal pairing of resolution and CPS. However, it is found that the sensitivity of DCP to CPSs and resolution varies with the partitioning between convective to stratiform, which implies that appropriate partitioning needs to be considered for future development of CPSs in global or regional climate models.},
	urldate = {2014-12-09},
	journal = {Weather and Forecasting},
	author = {He, Xiaogang and Kim, Hyungjun and Kirstetter, Pierre-Emmanuel and Yoshimura, Kei and Chang, Eun-Chul and Ferguson, Craig R. and Erlingis, Jessica M. and Hong, Yang and Oki, Taikan},
	month = nov,
	year = {2014},
	keywords = {AMMA-CATCH, extérieur},
	pages = {doi: http://dx.doi.org/10.1175/WAF--D--14--00013.1},
}

@article{laouali_long_2012,
	title = {Long term monitoring of the chemical composition of precipitation and wet deposition fluxes over three {Sahelian} savannas},
	volume = {50},
	issn = {1352-2310},
	url = {http://www.sciencedirect.com/science/article/pii/S1352231011012568},
	doi = {10.1016/j.atmosenv.2011.12.004},
	abstract = {The purpose of this study is to analyze a long term database of the chemical composition of precipitation at three African dry savanna sites in the Sahel. The precipitation samples were collected during the monsoon season at Agoufou (15°20′N, 01°29′W, Mali) from 2004 to 2006, Banizoumbou (13°31′N, 02°38′E, Niger) from 1994 to 2009 and Katibougou (12°56′N, 07°32′ W, Mali) from 1997 to 2008. pH and major inorganic and organic ions in precipitation were analyzed by ionic chromatography. A characterization of mean precipitation chemistry with the associated wet deposition fluxes for each species is presented. The first important result is that interannual variability of all volume-weighted mean (VWM) concentrations is low, ranging between ±5\% and ±25\%. Acidity in dry savannas is low and indicates the strong alkaline nature of the precipitation. The average annual pH at Agoufou is 6.28, 5.75 at Banizoumbou and 5.54 at Katibougou. This result is correlated with the important terrigenous contribution measured in the chemical content of precipitation, implying acidity neutralization by mineral species such as Ca2+ and NH4+. Mg2+ and K+ are found to play a minor role in neutralization. Enrichment factor calculations for Ca2+, SO42−, K+ and Mg2+ with respect to the sea reference reveal a significant influence of Saharan and Sahelian crustal sources. VWM concentrations of these species dominate the composition of measured precipitation. An estimation of the potential particulate and gas contribution to the total precipitation composition is given for each site: At Agoufou, the mean relative contribution in rainwater is 80\% for particles and 20\% for gases, while at the Banizoumbou and Katibougou sites, results indicate 70\% for particles and 30\% for gases. The high particulate phase contribution to precipitation emphasizes the importance of multiphase processes between gases and particles in the atmospheric chemistry typical of African semi-arid savanna ecosystems. The second highest contribution is nitrogenous, with high VWM concentrations of NO3− and NH4+ measured at the three sites. Monthly evolution of NO3− and NH4+ concentrations are studied in relation to gaseous emission sources in the Sahelian region, i.e. biogenic soil emission and ammonia sources from animals. The calculated wet nitrogen deposition flux presents a regular increase throughout the wet season at the three sites. Results suggest total mean nitrogen deposition fluxes of 1.80 kg N ha−1 yr−1 at Agoufou, 2.10 kg N ha−1 yr−1 at Banizoumbou, and 3.30 kg N ha−1 yr−1 at Katibougou. The marine contribution is lower, 23\% at Agoufou, 17\% at Banizoumbou and 13\% at Katibougou. The last contribution concerns organic acidity, which ranges from 5\% at Agoufou, 10\% at Banizoumbou to 14\% at Katibougou. Terrigenous and marine contributions present a negative gradient, whereas nitrogenous and organic contributions a positive gradient along the Sahelian transect defined by Agoufou–Banizoumbou–Katibougou.},
	urldate = {2014-12-09},
	journal = {Atmospheric Environment},
	author = {Laouali, D. and Galy-Lacaux, C. and Diop, B. and Delon, C. and Orange, D. and Lacaux, J. P. and Akpo, A. and Lavenu, F. and Gardrat, E. and Castera, P.},
	month = apr,
	year = {2012},
	keywords = {AMMA-CATCH, Niger, Mali, extérieur, African semi-arid ecosystems, Atmospheric chemistry, IDAF, Mineral species, Neutralization factor, Nitrogenous compounds, Sahelian savannas},
	pages = {314--327},
}

@article{paulik_validation_2014,
	title = {Validation of the {ASCAT} {Soil} {Water} {Index} using in situ data from the {International} {Soil} {Moisture} {Network}},
	volume = {30},
	issn = {0303-2434},
	url = {http://www.sciencedirect.com/science/article/pii/S0303243414000099},
	doi = {10.1016/j.jag.2014.01.007},
	abstract = {Soil moisture is an essential climate variable and a key parameter in hydrology, meteorology and agriculture. Surface Soil Moisture (SSM) can be estimated from measurements taken by ASCAT onboard Metop-A and have been successfully validated by several studies. Profile soil moisture, while equally important, cannot be directly measured by remote sensing but must be modeled. The Soil Water Index (SWI) product developed for near real time applications within the framework of the GMES project geoland2 aims to provide such a modeled profile estimate using satellite data as input. It is produced from ASCAT SSM estimates using a two-layer water balance model which describes the relationship between surface and profile soil moisture as a function of time. It provides daily global data about moisture conditions for eight characteristic time lengths representing different depths. The objective of this work was to assess the overall quality of the SWI data. Furthermore we tested the assumptions of the used water balance model and checked if ancillary information about topography, water fraction and noise information are useful for identifying observations of questionable quality. SWI data from January 1st 2007 until the end of 2011 was compared to in situ soil moisture data from 664 stations belonging to 23 observation networks which are available through the International Soil Moisture Network (ISMN). These stations delivered 2081 time series at different depths which were compared to the SWI values. The average of the significant Pearson correlation coefficients was 0.54 while being greater than 0.5 for 64.4\% of all time series. It was found that the characteristic time length showing the highest correlation increases with in situ observation depth, thus confirming the SWI model assumptions. Relationships of the correlation coefficients with topographic complexity, water fraction, in situ observation depth, and soil moisture noise were found.},
	urldate = {2014-12-09},
	journal = {International Journal of Applied Earth Observation and Geoinformation},
	author = {Paulik, Christoph and Dorigo, Wouter and Wagner, Wolgang and Kidd, Richard},
	month = aug,
	year = {2014},
	keywords = {remote sensing, validation, Soil moisture, AMMA-CATCH, extérieur, ISMN, Soil Water Index},
	pages = {1--8},
}

@article{xue_review_2012,
	title = {Review of {Recent} {Developments} and the {Future} {Prospective} in {West} {African} {Atmosphere}/{Land} {Interaction} {Studies}},
	volume = {2012},
	issn = {1687-885X},
	url = {http://www.hindawi.com/journals/ijge/2012/748921/abs/},
	doi = {10.1155/2012/748921},
	abstract = {This paper reviews West African land/atmosphere interaction studies during the past decade. Four issues are addressed in this paper: land data development, land/atmosphere interactions at seasonal-interannual scales, mesoscale studies, and the future prospective. The development of the AMMA Land Surface Model Intercomparison Project has produced a valuable analysis of the land surface state and fluxes which have been applied in a number of large-scale African regional studies. In seasonal-interannual West African climate studies, the latest evidence from satellite data analyses and modeling studies confirm that the West African region has a climate which is particularly sensitive to land surface processes and there is a strong coupling between land surface processes and regional climate at intraseasonal/seasonal scales. These studies indicate that proper land surface process representations and land status initialization would substantially improve predictions and enhance the predictability of West African climate. Mesoscale studies have revealed new understanding of how soil moisture heterogeneity influences the development of convective storms over the course of the diurnal cycle. Finally, several important issues regarding the future prospective are briefly addressed.},
	language = {en},
	urldate = {2014-12-09},
	journal = {International Journal of Geophysics},
	author = {Xue, Yongkang and Boone, Aaron and Taylor, Christopher M.},
	month = apr,
	year = {2012},
	keywords = {AMMA-CATCH, extérieur},
	pages = {e748921},
}

@article{schepanski_sensitivity_2014,
	title = {The sensitivity of nocturnal low-level jets and near-surface winds over the {Sahel} to model resolution, initial conditions and boundary-layer set-up},
	copyright = {© 2014 Royal Meteorological Society},
	issn = {1477-870X},
	url = {http://onlinelibrary.wiley.com/doi/10.1002/qj.2453/abstract},
	doi = {10.1002/qj.2453},
	abstract = {This study explores simulations using the numerical Weather Research and Forecasting (WRF) model, with respect to the representation of the nocturnal low-level jet (LLJ) over the Sahel. Three sets of experiments are designed to investigate the sensitivity with respect to (i) the boundary-layer and surface-layer schemes including local and non-local closures, (ii) the horizontal grid spacing and the number of vertical levels within the lowest kilometre and (iii) the role of initial and boundary data. In total, 27 simulations are performed on one host domain and two nested domains for a representative LLJ case study on 9 November 2006. The ability of the individual simulations to represent the life cycle of the nocturnal LLJ is validated against observations carried out in the framework of the African Monsoon Multidisciplinary Analysis (AMMA) special observation periods: surface wind observations from Agoufou, Bamba and Banizoumbou, atmospheric wind profiles derived from Atmospheric Radiation Measurement Mobile Facility, wind radar measurements at Niamey and profiles from radiosondes launched at Niamey. All runs reproduce the general characteristics of the observed LLJs satisfactorily. In contrast to earlier studies, results are more sensitive to the choice of initial and boundary data (here GFS and ECMWF) than to the boundary-layer and surface schemes used or to model grid resolution. The sensitivity to the model grid resolution is surprisingly minor. Considerable differences between the individual stations suggest that local surface conditions such as roughness length, albedo or soil moisture may play an important role in the observed mismatch between model simulations and observations.},
	language = {en},
	urldate = {2014-12-09},
	journal = {Quarterly Journal of the Royal Meteorological Society},
	author = {Schepanski, K. and Knippertz, P. and Fiedler, S. and Timouk, F. and Demarty, J.},
	month = oct,
	year = {2014},
	keywords = {AMMA, Sahel, AMMA-CATCH, AO, nocturnal low-level jet, regional modeling, WRF},
	pages = {DOI: 10.1002/qj.2453},
}

@article{liu_trend-preserving_2012,
	title = {Trend-preserving blending of passive and active microwave soil moisture retrievals},
	volume = {123},
	issn = {0034-4257},
	url = {http://www.sciencedirect.com/science/article/pii/S0034425712001332},
	doi = {10.1016/j.rse.2012.03.014},
	abstract = {A series of satellite-based passive and active microwave instruments provide soil moisture retrievals spanning altogether more than three decades. This offers the opportunity to generate a combined product that incorporates the advantages of both microwave techniques and spans the observation period starting 1979. However, there are several challenges in developing such a dataset, e.g., differences in instrument specifications result in different absolute soil moisture values, the global passive and active microwave retrieval methods produce conceptually different quantities, and products vary in their relative performances depending on vegetation density. This paper presents an approach for combining four passive microwave products from the VU University Amsterdam/National Aeronautics and Space Administration and two active microwave products from the Vienna University of Technology. First, passive microwave soil moisture retrievals from the Scanning Multichannel Microwave Radiometer (SMMR), the Special Sensor Microwave Imager (SSM/I), and the Tropical Rainfall Measuring Mission microwave imager (TMI) instruments were scaled to the climatology of the Advanced Microwave Scanning Radiometer — Earth Observing System (AMSR-E) derived product and then all four were combined into a single merged passive microwave product. Second, active microwave soil moisture estimates from the European Remote Sensing (ERS) Scatterometer instrument were scaled to the climatology of the Advanced Scatterometer (ASCAT) derived estimates. Both were combined into a merged active microwave product. Finally, the two merged products were rescaled to a common globally available reference soil moisture dataset provided by a land surface model (GLDAS-1-Noah) and then blended into a single passive/active product. Blending of the active and passive data sets was based on their respective sensitivity to vegetation density. While this three step approach imposes the absolute values of the land surface model dataset to the final product, it preserves the relative dynamics (e.g., seasonality and inter-annual variations) of the original satellite derived retrievals. More importantly, the long term changes evident in the original soil moisture products were also preserved. The method presented in this paper allows the long term product to be extended with data from other current and future operational satellites. The multi-decadal blended dataset is expected to enhance our basic understanding of soil moisture in the water, energy and carbon cycles.},
	urldate = {2014-12-09},
	journal = {Remote Sensing of Environment},
	author = {Liu, Y. Y. and Dorigo, W. A. and Parinussa, R. M. and de Jeu, R. A. M. and Wagner, W. and McCabe, M. F. and Evans, J. P. and van Dijk, A. I. J. M.},
	month = aug,
	year = {2012},
	keywords = {Soil moisture, Satellite, AMMA-CATCH, extérieur, ISMN, Active and passive microwave, Blending, Long term trend},
	pages = {280--297},
}

@article{pierre_comparing_2014,
	title = {Comparing drag partition schemes over a herbaceous {Sahelian} rangeland},
	volume = {119},
	copyright = {©2014. American Geophysical Union. All Rights Reserved.},
	issn = {2169-9011},
	url = {http://onlinelibrary.wiley.com/doi/10.1002/2014JF003177/abstract},
	doi = {10.1002/2014JF003177},
	abstract = {Modeling of dust emissions from the surface remains complex, especially in semiarid regions where vegetation must be accounted for because of its potentially important protective effect. Protection is directly linked to the fraction of the soil surface covered by vegetation, but it is also driven by the interaction of vegetation elements with the wind field. The sensitivity of simulated dust emissions to various drag partition schemes—mainly those proposed by Raupach (1992), Marticorena and Bergametti (1995), and Okin (2008)—is evaluated for a typical Sahelian rangeland, covered by a seasonal grass layer, over a complete vegetation cycle. The application of these schemes requires a fine characterization of the vegetation cover; field measurements from an ecological survey are used to derive the geometric dimensions of the grass patches. Models are run with meteorological forcing from automatic weather stations. As a result, the impacts of soil moisture and grass cover are estimated over April to September. Soil moisture inhibits dust emissions by 27\% in mass. The different drag partition schemes exhibit distinctive limitations, mostly due to the properties of the Sahelian grass cover, which is composed of large and low patches of short grass, with a strong seasonal dynamics. However, the drag partition schemes result in remarkably coherent estimations of dust emissions. When soil moisture is taken into account, vegetation reduces the total vertical mass fluxes by 6 to 26\% of the emissions of a bare soil, depending on the drag partition scheme.},
	language = {en},
	number = {10},
	urldate = {2014-12-09},
	journal = {Journal of Geophysical Research: Earth Surface},
	author = {Pierre, C. and Bergametti, G. and Marticorena, B. and Kergoat, L. and Mougin, E. and Hiernaux, P.},
	month = oct,
	year = {2014},
	keywords = {3322 Land/atmosphere interactions, Modeling, AMMA-CATCH, 0305 Aerosols and particles, 0545 Modeling, 5415 Erosion and weathering, drag partition, dust emission, herbaceous and woody vegetation, Sahelian semiarid area, wind erosion},
	pages = {2014JF003177},
}

@article{koffi_evaluation_2014,
	title = {Evaluation of {X}-band polarimetric radar estimation of rainfall and rain drop size distribution parameters in {West} {Africa}},
	volume = {143},
	issn = {0169-8095},
	url = {http://www.sciencedirect.com/science/article/pii/S0169809514001331},
	doi = {10.1016/j.atmosres.2014.03.009},
	abstract = {As part of the African Monsoon Multidisciplinary Analysis (AMMA) field campaign an X-band dual-polarization Doppler radar was deployed in Benin, West-Africa, in 2006 and 2007, together with a reinforced rain gauge network and several optical disdrometers. Based on this data set, a comparative study of several rainfall estimators that use X-band polarimetric radar data is presented. In tropical convective systems as encountered in Benin, microwave attenuation by rain is significant and quantitative precipitation estimation (QPE) at X-band is a challenge. Here, several algorithms based on the combined use of reflectivity, differential reflectivity and differential phase shift are evaluated against rain gauges and disdrometers. Four rainfall estimators were tested on twelve rainy events: the use of attenuation corrected reflectivity only (estimator R(ZH)), the use of the specific phase shift only R(KDP), the combination of specific phase shift and differential reflectivity R(KDP,ZDR) and an estimator that uses three radar parameters R(ZH,ZDR,KDP). The coefficients of the power law relationships between rain rate and radar variables were adjusted either based on disdrometer data and simulation, or on radar-gauges observations. The three polarimetric based algorithms with coefficients predetermined on observations outperform the R(ZH) estimator for rain rates above 10 mm/h which explain most of the rainfall in the studied region. For the highest rain rates (above 30 mm/h) R(KDP) shows even better scores, and given its performances and its simplicity of implementation, is recommended. The radar based retrieval of two parameters of the rain drop size distribution, the normalized intercept parameter NW and the volumetric median diameter Dm was evaluated on four rainy days thanks to disdrometers. The frequency distributions of the two parameters retrieved by the radar are very close to those observed with the disdrometer. NW retrieval based on a combination of ZH–KDP–ZDR works well whatever the a priori assumption made on the drop shapes. Dm retrieval based on ZDR alone performs well, but if satisfactory ZDR measurements are not available, the combination ZH–KDP provides satisfactory results for both Dm and NW if an appropriate a priori assumption on drop shape is made.},
	urldate = {2014-12-09},
	journal = {Atmospheric Research},
	author = {Koffi, A. K. and Gosset, M. and Zahiri, E. -P. and Ochou, A. D. and Kacou, M. and Cazenave, F. and Assamoi, P.},
	month = jun,
	year = {2014},
	keywords = {AMMA-CATCH, IGE, radar, benin, convective rainfall, Drop size distribution (DSD), Polarimetric radar, Quantitative precipitation estimate (QPE), Tropical convection},
	pages = {438--461},
}

@article{mbow_advances_2014,
	title = {Advances in monitoring vegetation and land use dynamics in the {Sahel}},
	volume = {114},
	issn = {0016-7223},
	url = {http://dx.doi.org/10.1080/00167223.2014.886515},
	doi = {10.1080/00167223.2014.886515},
	abstract = {Vegetation dynamics of the West African Sahel has attracted great scientific interest over the last 40 years because of the dramatic inter-decadal variability observed in the resource base of the region directly impacting on the livelihoods of the West African population. From farmers to pastoralists, agro-pastoralists and forest-users, all depend on the availability of vegetation resources and are affected by fluctuations in the available vegetation resource. Vegetation dynamics are controlled by both natural and human factors, including climate change and variability, increased concentration of CO2 in the atmosphere, grazing pressure, bush fires and agricultural expansion or contraction. The use of satellite data in combination with field data played a major role in the monitoring of vegetation dynamics and land use in the Sahel, since the mega drought of the 1970s and the 1980s. This paper briefly reviews the advance of satellite-based monitoring of vegetation dynamics over these 40 years. We discuss the promises of current and likely future data sources and analysis tools, as well as the need to strengthen in situ data collection to support and validate satellite-based vegetation and land use monitoring and modelling.},
	number = {1},
	urldate = {2014-12-09},
	journal = {Geografisk Tidsskrift-Danish Journal of Geography},
	author = {Mbow, Cheikh and Fensholt, Rasmus and Nielsen, Thomas Theis and Rasmussen, Kjeld},
	month = jan,
	year = {2014},
	keywords = {AMMA-CATCH, extérieur},
	pages = {84--91},
}

@article{haas_remotely_2011,
	title = {Remotely sensed surface water extent as an indicator of short-term changes in ecohydrological processes in sub-{Saharan} {Western} {Africa}},
	volume = {115},
	issn = {0034-4257},
	url = {http://www.sciencedirect.com/science/article/pii/S0034425711002896},
	doi = {10.1016/j.rse.2011.08.007},
	abstract = {The highly variable rainfall in the arid and semi-arid regions of sub-Saharan Western Africa drives both surface water availability and vegetation cover. Recent studies have established linkages between rainfall and vegetation cover at local to regional scales, but no study related yet remote sensing derived rainfall and vegetation cover to the available surface water. A new dataset based on SPOT VEGETATION (VGT) represents surface water bodies (SWB) in the arid and semi-arid regions of sub-Saharan Western Africa. Water bodies represent the integrated hydrological response of a catchment, and changes in their spatial extent involve complex interactions at the catchment scale. We analyzed time series of remotely sensed vegetation cover, rainfall and surface water extent for the period 1999–2008, and could detect and statistically demonstrate the links between these biophysical variables. Our findings for two regions in Mali and Burkina Faso suggest that vegetation cover is positively related to the amount of available surface water for those catchments that are mainly covered by annual plants. The observed relationships between remotely sensed variables allow developing ecological indicators that can indicate short-term changes in arid and semi-arid ecosystems at local to regional scales.},
	number = {12},
	urldate = {2014-12-09},
	journal = {Remote Sensing of Environment},
	author = {Haas, Eva Maria and Bartholomé, Etienne and Lambin, Eric F. and Vanacker, Veerle},
	month = dec,
	year = {2011},
	keywords = {Sahel, AMMA-CATCH, extérieur, AO, Ecohydrology, Ecological indicators, Temporary water bodies},
	pages = {3436--3445},
}

@article{masih_review_2014,
	title = {A review of droughts on the {African} continent: a geospatial and long-term perspective},
	volume = {18},
	issn = {1607-7938},
	shorttitle = {A review of droughts on the {African} continent},
	url = {http://www.hydrol-earth-syst-sci.net/18/3635/2014/},
	doi = {10.5194/hess-18-3635-2014},
	abstract = {This paper presents a comprehensive review and analysis of the available literature and information on droughts to build a continental, regional and country level perspective on geospatial and temporal variation of droughts in Africa. The study is based on the review and analysis of droughts occurred during 1900–2013, as well as evidence available from past centuries based on studies on the lake sediment analysis, tree-ring chronologies and written and oral histories and future predictions from the global climate change models. Most of the studies based on instrumental records indicate that droughts have become more frequent, intense and widespread during the last 50 years. The extreme droughts of 1972–1973, 1983–1984 and 1991–1992 were continental in nature and stand unique in the available records. Additionally, many severe and prolonged droughts were recorded in the recent past such as the 1999–2002 drought in northwest Africa, 1970s and 1980s droughts in western Africa (Sahel), 2010–2011 drought in eastern Africa (Horn of Africa) and 2001–2003 drought in southern and southeastern Africa, to name a few. The available (though limited) evidence before the 20th century confirms the occurrence of several extreme and multi-year droughts during each century, with the most prolonged and intense droughts that occurred in Sahel and equatorial eastern Africa. The complex and highly variant nature of many physical mechanisms such as El Niño–Southern Oscillation (ENSO), sea surface temperature (SST) and land–atmosphere feedback adds to the daunting challenge of drought monitoring and forecasting. The future predictions of droughts based on global climate models indicate increased droughts and aridity at the continental scale but large differences exist due to model limitations and complexity of the processes especially for Sahel and northern Africa. However, the available evidence from the past clearly shows that the African continent is likely to face extreme and widespread droughts in future. This evident challenge is likely to aggravate due to slow progress in drought risk management, increased population and demand for water and degradation of land and environment. Thus, there is a clear need for increased and integrated efforts in drought mitigation to reduce the negative impacts of droughts anticipated in the future.},
	number = {9},
	urldate = {2014-12-09},
	journal = {Hydrol. Earth Syst. Sci.},
	author = {Masih, I. and Maskey, S. and Mussá, F. E. F. and Trambauer, P.},
	month = sep,
	year = {2014},
	keywords = {AMMA-CATCH, extérieur},
	pages = {3635--3649},
}

@article{vouillamoz_groundwater_2015,
	title = {Groundwater in hard rocks of {Benin}: {Regional} storage and buffer capacity in the face of change},
	volume = {520},
	issn = {0022-1694},
	shorttitle = {Groundwater in hard rocks of {Benin}},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0022169414009299},
	doi = {10.1016/j.jhydrol.2014.11.024},
	abstract = {Summary Groundwater plays a major role in supplying domestic water to millions of people in Africa. In the future, the ability to increase reliable water supplies for domestic and possibly irrigation purposes will depend on groundwater development. Groundwater storage is a key property because it controls the buffering behavior of the aquifer as it is subjected to time-varying conditions such as increased pumping or land-use change. However, quantitative knowledge of groundwater storage in Africa is very limited. This lack of knowledge is a major concern in hard rocks, which cover about 40\% of the surface area of Africa. This paper presents a unique quantitative assessment of groundwater storage in different types of hard rocks and a first estimate of the capacity of hard rock aquifers to buffer changes in climatic and anthropogenic conditions. Our study area in Benin (West Africa) is composed of various grades of metamorphic rocks. We used the latest developments in the application of the magnetic resonance geophysical method to confront the methodological difficulty of quantifying groundwater storage. We successfully conducted 38 magnetic-resonance measurements in eight (8) different geological units; each measurement was quantitatively interpreted in terms of groundwater storage. We determined the groundwater storage of our study area to be 440 mm ± 70 mm (equivalent water thickness). To assess the buffer capacity of aquifers, we compared groundwater storage to groundwater discharge. Groundwater discharge is the sum of natural discharge plus human abstraction. We estimated natural discharge (i.e. deep drainage plus evapotranspiration) from water table fluctuations monitored in six (6) piezometers. Human abstraction was calculated based on the number of operating boreholes and their average daily abstraction. We found that human abstraction (0.34 mm/year ± 0.07 mm) is far less than natural discharge (108 mm/year ± 58 mm). We conclude that increased abstraction due to population growth will probably have a smaller impact on storage than observed land-use change, which may lead to a change in the evapotranspiration rate. We calculated buffer capacity as the ratio of current storage to total discharge, and obtained a result of 6 years ± 47 months. This buffer capacity confirms groundwater’s ability to buffer changes. Finally, our study is intended to promote a more quantitative approach to assessing groundwater resources in Africa and to support our ability to adapt to current and future changes.},
	language = {en},
	urldate = {2015-03-26},
	journal = {Journal of Hydrology},
	author = {Vouillamoz, J-M. and Lawson, F.M.A. and Yalo, N. and Descloitres, M.},
	month = jan,
	year = {2015},
	keywords = {Climate change, Hard rock aquifers, Magnetic resonance sounding, Specific yield, Buffer capacity, Groundwater storage, AMMA-CATCH, HYBIS, benin, PHYREV, socle, griba},
	pages = {379--386},
}

@article{largeron_can_2015,
	title = {Can we use surface wind fields from meteorological reanalyses for {Sahelian} dust emission simulations?},
	issn = {00948276},
	url = {http://doi.wiley.com/10.1002/2014GL062938},
	doi = {10.1002/2014GL062938},
	language = {en},
	urldate = {2015-04-15},
	journal = {Geophysical Research Letters},
	author = {Largeron, Yann and Guichard, Francoise and Bouniol, Dominique and Couvreux, Fleur and Kergoat, Laurent and Marticorena, Béatrice},
	month = apr,
	year = {2015},
	keywords = {AMMA-CATCH, ext1},
	pages = {n/a--n/a},
}

@article{kergoat_dry-season_2015,
	title = {Dry-season vegetation mass and cover fraction from {SWIR1}.6 and {SWIR2}.1 band ratio: {Ground}-radiometer and {MODIS} data in the {Sahel}},
	volume = {39},
	issn = {03032434},
	shorttitle = {Dry-season vegetation mass and cover fraction from {SWIR1}.6 and {SWIR2}.1 band ratio},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0303243415000434},
	doi = {10.1016/j.jag.2015.02.011},
	language = {en},
	urldate = {2015-04-15},
	journal = {International Journal of Applied Earth Observation and Geoinformation},
	author = {Kergoat, L. and Hiernaux, P. and Dardel, C. and Pierre, C. and Guichard, F. and Kalilou, A.},
	month = jul,
	year = {2015},
	keywords = {Sahel, AMMA-CATCH, AO},
	pages = {56--64},
}

@article{dardel_re-greening_2014,
	title = {Re-greening {Sahel}: 30years of remote sensing data and field observations ({Mali}, {Niger})},
	volume = {140},
	issn = {0034-4257},
	shorttitle = {Re-greening {Sahel}},
	url = {http://www.sciencedirect.com/science/article/pii/S0034425713003325},
	doi = {10.1016/j.rse.2013.09.011},
	abstract = {Desertification of the Sahel region has been debated for decades, while the concept of a “re-greening” Sahel appeared with satellite remote sensing data that allowed vegetation monitoring across wide regions and over increasingly long series of years (nowadays 30years with the GIMMS-3g dataset). However, the scarcity of long-term field observations of vegetation in the Sahel prevents ground validation and deeper analysis of such trends. After assessing the consistency of the new GIMMS-3g NDVI product by comparison to three other AVHRR-NDVI datasets and MODIS NDVI, regional GIMMS-3g NDVI trends over 1981–2011 are analyzed. Trends are found positive and statistically significant almost everywhere in Sahel over the 1981–2011 period. Long-term field observations of the aboveground herbaceous layer mass have been collected within the Gourma region in Mali (1984–2011) and within the Fakara region in western Niger (1994–2011). These observations sample ecosystem and soil diversity, thus enabling estimation of averaged values representative of the Gourma and Fakara. NDVI measurements are found in good agreement with field observations, both over the Gourma and Fakara regions where re-greening and negative trends are observed respectively. A linear regression analysis performed between spatially averaged seasonal NDVI and a weighted average of field measurements explains 59\% of the variability for the Gourma region over 1984–2011, and 38\% for the Fakara region over 1994–2011. In the Gourma, which is a pastoral region, the re-greening trend is mainly observed over sandy soils, and attests for the ecosystem's resilience to the 1980s' drought, able to react to the more favorable rainfall of the 1990s and 2000s. However, contrasted changes in the landscape's functioning have occurred locally. An increase in erosion and run-off processes in association with decreasing or stable vegetation cover was observed over shallow soils, which occupy 30\% of the area. In the agro-pastoral Fakara, the decreasing trends observed both from satellite NDVI and field assessments of herbaceous mass are hardly explained by rainfall. These results give confidence in the dominant positive trends in Sahelian greenness, but indicate that degradation trends can also be observed, both in situ and from satellite time series.},
	language = {en},
	urldate = {2014-06-13},
	journal = {Remote Sensing of Environment},
	author = {Dardel, C. and Kergoat, L. and Hiernaux, P. and Mougin, E. and Grippa, M. and Tucker, C.J.},
	month = jan,
	year = {2014},
	keywords = {Sahel, AMMA-CATCH, Niger, AVHHR, Desertification, Field measurements, Herbaceous production, Mali, NDVI, Re-greening, Trend analysis, mali},
	pages = {350--364},
}

@article{lehmann_savanna_2014,
	title = {Savanna {Vegetation}-{Fire}-{Climate} {Relationships} {Differ} {Among} {Continents}},
	volume = {343},
	issn = {0036-8075, 1095-9203},
	url = {http://www.sciencemag.org/cgi/doi/10.1126/science.1247355},
	doi = {10.1126/science.1247355},
	language = {en},
	number = {6170},
	urldate = {2014-06-13},
	journal = {Science},
	author = {Lehmann, C. E. R. and Anderson, T. M. and Sankaran, M. and Higgins, S. I. and Archibald, S. and Hoffmann, W. A. and Hanan, N. P. and Williams, R. J. and Fensham, R. J. and Felfili, J. and Hutley, L. B. and Ratnam, J. and San Jose, J. and Montes, R. and Franklin, D. and Russell-Smith, J. and Ryan, C. M. and Durigan, G. and Hiernaux, P. and Haidar, R. and Bowman, D. M. J. S. and Bond, W. J.},
	month = jan,
	year = {2014},
	keywords = {AMMA-CATCH},
	pages = {548--552},
}

@article{frison_analysis_2013,
	title = {Analysis of {L}- and {C}-{Band} {SAR} {Image} {Time} {Series} {Over} a {Sahelian} {Area}},
	volume = {10},
	issn = {1545-598X, 1558-0571},
	url = {http://ieeexplore.ieee.org/lpdocs/epic03/wrapper.htm?arnumber=6414594},
	doi = {10.1109/LGRS.2012.2227931},
	number = {5},
	urldate = {2014-06-13},
	journal = {IEEE Geoscience and Remote Sensing Letters},
	author = {Frison, P.-L and Mercier, G. and Faye, G. and Mougin, E. and Hiernaux, P. and Lardeux, C. and Rudant, J.-P},
	month = sep,
	year = {2013},
	keywords = {Sahel, Soil moisture, vegetation mapping, AMMA-CATCH, Spaceborne radar, Mali, AO, Vegetation, Gourma region, Radar, Time series analysis, Sandy soil, l-band, ALOS-Phased Array-type L-band SAR, ALOS/Phased Array-type L-band SAR (PALSAR), C-band SAR image, dual mode, Environment Satellite-Advanced SAR sensor, ENVISAT/Advanced Synthetic Aperture Radar (ASAR), fine mode, geophysical image processing, hue-saturation-value transform, L-band SAR image, permanent pond, radar imaging, random projection, remote sensing by radar, Sahelian area, sand, semiarid regions, soil, surface change, synthetic aperture radar, synthetic aperture radar (SAR), temporal change detection, temporary pond, terrain mapping, time series, transforms, vegetation growth, wide swath mode},
	pages = {1016--1020},
}

@article{garcia_actual_2013,
	title = {Actual evapotranspiration in drylands derived from in-situ and satellite data: {Assessing} biophysical constraints},
	volume = {131},
	issn = {00344257},
	shorttitle = {Actual evapotranspiration in drylands derived from in-situ and satellite data},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425712004828},
	doi = {10.1016/j.rse.2012.12.016},
	language = {en},
	urldate = {2014-06-13},
	journal = {Remote Sensing of Environment},
	author = {García, Monica and Sandholt, Inge and Ceccato, Pietro and Ridler, Marc and Mougin, Eric and Kergoat, Laurent and Morillas, Laura and Timouk, Franck and Fensholt, Rasmus and Domingo, Francisco},
	month = apr,
	year = {2013},
	keywords = {AMMA-CATCH},
	pages = {103--118},
}

@article{kirstetter_error_2013,
	title = {An error model for instantaneous satellite rainfall estimates: evaluation of {BRAIN}-{TMI} over {West} {Africa}},
	volume = {139},
	issn = {00359009},
	shorttitle = {An error model for instantaneous satellite rainfall estimates},
	url = {http://doi.wiley.com/10.1002/qj.1964},
	doi = {10.1002/qj.1964},
	language = {en},
	number = {673},
	urldate = {2014-06-13},
	journal = {Quarterly Journal of the Royal Meteorological Society},
	author = {Kirstetter, Pierre-Emmanuel and Viltard, Nicolas and Gosset, Marielle},
	month = apr,
	year = {2013},
	keywords = {AMMA-CATCH},
	pages = {894--911},
}

@article{le_coz_modeling_2013,
	title = {Modeling {Increased} {Groundwater} {Recharge} due to {Change} from {Rainfed} to {Irrigated} {Cropping} in a {Semiarid} {Region}},
	volume = {12},
	issn = {1539-1663},
	url = {https://www.soils.org/publications/vzj/abstracts/12/2/vzj2012.0148},
	doi = {10.2136/vzj2012.0148},
	abstract = {This paper deals with the application of a two-step method for quantifying changes in groundwater recharge due to an increase in irrigated areas in semiarid regions. This method was applied in the Komadugu Yobe River valley (southeastern Niger, Lake Chad Basin) and showed that irrigation development has resulted in a significant increase in recharge. Land use conversion from rainfed to irrigated cropping increases drainage and groundwater recharge, yet reliable estimates of the magnitude of the change are difficult to obtain for shallow aquifers. In the semiarid Komadugu Yobe River valley (Lake Chad basin, SE Niger), the area of irrigated cropping has doubled in the last three decades, which may have increased recharge fluxes to the shallow (∼6 m in depth) water table. To quantify the increase in recharge, water flow in the vadose zone was modeled, taking into account the predetermined heterogeneity of the River alluvium. For each sedimentary unit, soil moisture was monitored in situ under controlled hydraulic surface conditions by vertical neutron probe surveys. Using one-dimensional numerical simulations in a Monte-Carlo procedure, probability density functions (PDFs) of soil hydraulic parameters that reproduce moisture measurements were established. The centers of the PDFs were shown to be in accordance with the textural classification inferred from grain size analyses. The PDFs were then combined with a three-dimensional geological model of the alluvium and the groundwater recharge was simulated separately under irrigated and rainfed cropping conditions. The results showed that the uncertainty in soil hydraulic parameters (i) strongly influenced the absolute values of the simulated recharge, but (ii) only slightly affected the simulated differential recharge between irrigated and rainfed cropping conditions. The increase in groundwater recharge was therefore well constrained and was estimated at 15 cm (dry year) and 25 cm (wet year), i.e., representing 18 and 23\% of water input. The approach described here is applicable to most shallow aquifers in River valleys where surface water is used for irrigation, a widespread characteristic of semiarid regions.},
	language = {en},
	number = {2},
	urldate = {2014-06-13},
	journal = {Vadose Zone Journal},
	author = {Le Coz, Mathieu and Favreau, Guillaume and Ousmane, Sani Daouda},
	year = {2013},
	keywords = {AMMA-CATCH, Lake Chad Basin},
	pages = {0},
}

@article{olsen_relation_2013,
	title = {Relation between {Seasonally} {Detrended} {Shortwave} {Infrared} {Reflectance} {Data} and {Land} {Surface} {Moisture} in {Semi}‑{Arid} {Sahel}},
	volume = {5},
	issn = {2072-4292},
	url = {http://www.mdpi.com/2072-4292/5/6/2898/},
	doi = {10.3390/rs5062898},
	language = {en},
	number = {6},
	urldate = {2014-06-13},
	journal = {Remote Sensing},
	author = {Olsen, Jørgen and Ceccato, Pietro and Proud, Simon and Fensholt, Rasmus and Grippa, Manuela and Mougin, Eric and Ardö, Jonas and Sandholt, Inge},
	month = jun,
	year = {2013},
	keywords = {AMMA-CATCH},
	pages = {2898--2927},
}

@article{ramarohetra_how_2013,
	title = {How satellite rainfall estimate errors may impact rainfed cereal yield simulation in {West} {Africa}},
	volume = {180},
	issn = {01681923},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192313001548},
	doi = {10.1016/j.agrformet.2013.05.010},
	language = {en},
	urldate = {2014-06-13},
	journal = {Agricultural and Forest Meteorology},
	author = {Ramarohetra, Johanna and Sultan, Benjamin and Baron, Christian and Gaiser, Thomas and Gosset, Marielle},
	month = oct,
	year = {2013},
	keywords = {AMMA-CATCH},
	pages = {118--131},
}

@article{sjostrom_evaluation_2013,
	title = {Evaluation of {MODIS} gross primary productivity for {Africa} using eddy covariance data},
	volume = {131},
	issn = {00344257},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425712004890},
	doi = {10.1016/j.rse.2012.12.023},
	language = {en},
	urldate = {2014-06-13},
	journal = {Remote Sensing of Environment},
	author = {Sjöström, M. and Zhao, M. and Archibald, S. and Arneth, A. and Cappelaere, B. and Falk, U. and de Grandcourt, A. and Hanan, N. and Kergoat, L. and Kutsch, W. and Merbold, L. and Mougin, E. and Nickless, A. and Nouvellon, Y. and Scholes, R.J. and Veenendaal, E.M. and Ardö, J.},
	month = apr,
	year = {2013},
	keywords = {AMMA-CATCH},
	pages = {275--286},
}

@article{torello-raventos_delineation_2013,
	title = {On the delineation of tropical vegetation types with an emphasis on forest/savanna transitions},
	volume = {6},
	issn = {1755-0874, 1755-1668},
	url = {http://www.tandfonline.com/doi/abs/10.1080/17550874.2012.762812},
	doi = {10.1080/17550874.2012.762812},
	language = {en},
	number = {1},
	urldate = {2014-06-13},
	journal = {Plant Ecology \& Diversity},
	author = {Torello-Raventos, Mireia and Feldpausch, Ted R. and Veenendaal, Elmar and Schrodt, Franziska and Saiz, Gustavo and Domingues, Tomas F. and Djagbletey, Gloria and Ford, Andrew and Kemp, Jeanette and Marimon, Beatriz S. and Hur Marimon Junior, Ben and Lenza, Eddie and Ratter, James A. and Maracahipes, Leandro and Sasaki, Denise and Sonké, Bonaventure and Zapfack, Louis and Taedoumg, Hermann and Villarroel, Daniel and Schwarz, Michael and Quesada, Carlos A. and Yoko Ishida, F. and Nardoto, Gabriela B. and Affum-Baffoe, Kofi and Arroyo, Luzmilla and M.J.S. Bowman, David and Compaore, Halidou and Davies, Kalu and Diallo, Adama and Fyllas, Nikolaos M. and Gilpin, Martin and Hien, Fidèle and Johnson, Michelle and Killeen, Timothy J. and Metcalfe, Daniel and Miranda, Heloisa S. and Steininger, Mark and Thomson, John and Sykora, Karle and Mougin, Eric and Hiernaux, Pierre and Bird, Michael I. and Grace, John and Lewis, Simon L. and Phillips, Oliver L. and Lloyd, Jon},
	month = mar,
	year = {2013},
	keywords = {AMMA-CATCH},
	pages = {101--137},
}

@article{torou_constraints_2013,
	title = {Constraints and opportunities for groundwater irrigation arising from hydrologic shifts in the {Iullemmeden} {Basin}, south-western {Niger}},
	volume = {38},
	issn = {0250-8060, 1941-1707},
	url = {http://www.tandfonline.com/doi/abs/10.1080/02508060.2013.817042},
	doi = {10.1080/02508060.2013.817042},
	language = {en},
	number = {4},
	urldate = {2014-06-13},
	journal = {Water International},
	author = {Torou, Bio Mohamadou and Favreau, Guillaume and Barbier, Bruno and Pavelic, Paul and Illou, Mahamadou and Sidibé, Fatoumata},
	month = jul,
	year = {2013},
	keywords = {AMMA-CATCH},
	pages = {465--479},
}

@article{lesnoff_sensitivity_2012,
	title = {Sensitivity analysis of the recovery dynamics of a cattle population following drought in the {Sahel} region},
	volume = {232},
	issn = {03043800},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0304380012000944},
	doi = {10.1016/j.ecolmodel.2012.02.018},
	language = {en},
	urldate = {2014-06-13},
	journal = {Ecological Modelling},
	author = {Lesnoff, Matthieu and Corniaux, Christian and Hiernaux, Pierre},
	month = may,
	year = {2012},
	keywords = {AMMA-CATCH},
	pages = {28--39},
}

@article{issoufou_is_2015,
	title = {Is the {WBE} model appropriate for semi-arid shrubs subjected to clear cutting?},
	volume = {35},
	issn = {0829-318X, 1758-4469},
	url = {http://treephys.oxfordjournals.org/cgi/doi/10.1093/treephys/tpv002},
	doi = {10.1093/treephys/tpv002},
	language = {en},
	number = {2},
	urldate = {2015-05-04},
	journal = {Tree Physiology},
	author = {Issoufou, H. B.-A. and Rambal, S. and Le Dantec, V. and Oi, M. and Laurent, J.-P. and Saadou, M. and Seghieri, J.},
	month = feb,
	year = {2015},
	keywords = {Sahel, model, AMMA-CATCH, AO, PHYREV},
	pages = {197--208},
}

@article{mangiarotti_predictability_2012,
	title = {Predictability of vegetation cycles over the semi-arid region of {Gourma} ({Mali}) from forecasts of {AVHRR}-{NDVI} signals},
	volume = {123},
	issn = {00344257},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425712001307},
	doi = {10.1016/j.rse.2012.03.011},
	language = {en},
	urldate = {2014-06-13},
	journal = {Remote Sensing of Environment},
	author = {Mangiarotti, S. and Mazzega, P. and Hiernaux, P. and Mougin, E.},
	month = aug,
	year = {2012},
	keywords = {AMMA-CATCH, Mali},
	pages = {246--257},
}

@article{pierre_impact_2012,
	title = {Impact of vegetation and soil moisture seasonal dynamics on dust emissions over the {Sahel}},
	volume = {117},
	issn = {0148-0227},
	url = {http://doi.wiley.com/10.1029/2011JD016950},
	doi = {10.1029/2011JD016950},
	language = {en},
	number = {D6},
	urldate = {2014-06-13},
	journal = {Journal of Geophysical Research},
	author = {Pierre, C. and Bergametti, G. and Marticorena, B. and Mougin, E. and Bouet, C. and Schmechtig, C.},
	month = mar,
	year = {2012},
	keywords = {AMMA-CATCH},
}

@article{ridler_calibrating_2012,
	title = {Calibrating a soil–vegetation–atmosphere transfer model with remote sensing estimates of surface temperature and soil surface moisture in a semi arid environment},
	volume = {436-437},
	issn = {00221694},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0022169412001862},
	doi = {10.1016/j.jhydrol.2012.01.047},
	language = {en},
	urldate = {2014-06-13},
	journal = {Journal of Hydrology},
	author = {Ridler, Marc E. and Sandholt, Inge and Butts, Michael and Lerer, Sara and Mougin, Eric and Timouk, Franck and Kergoat, Laurent and Madsen, Henrik},
	month = may,
	year = {2012},
	keywords = {AMMA-CATCH},
	pages = {1--12},
}

@article{verhoef_spatio-temporal_2012,
	title = {Spatio-temporal surface soil heat flux estimates from satellite data; results for the {AMMA} experiment at the {Fakara} ({Niger}) supersite},
	volume = {154-155},
	issn = {01681923},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192311002607},
	doi = {10.1016/j.agrformet.2011.08.003},
	language = {en},
	urldate = {2014-06-13},
	journal = {Agricultural and Forest Meteorology},
	author = {Verhoef, Anne and Ottlé, Catherine and Cappelaere, Bernard and Murray, Ty and Saux-Picart, Stephane and Zribi, Mehrez and Maignan, Fabienne and Boulain, Nicolas and Demarty, Jerome and Ramier, David},
	month = mar,
	year = {2012},
	keywords = {AMMA-CATCH},
	pages = {55--66},
}

@article{baup_mapping_2011,
	title = {Mapping surface soil moisture over the {Gourma} mesoscale site ({Mali}) by using {ENVISAT} {ASAR} data},
	volume = {15},
	issn = {1607-7938},
	url = {http://www.hydrol-earth-syst-sci.net/15/603/2011/},
	doi = {10.5194/hess-15-603-2011},
	abstract = {The potentialities of ENVISAT ASAR (Advanced Synthetic Aperture Radar) multi-angle data for mapping surface soil moisture (SSM) in Sahelian rangelands are investigated at medium scale (30 000 km2). The Wide Swath data are selected to take advantage of their high temporal repetitivity (about 8 days at the considered scale) associated to a moderate spatial resolution (150 m). In the continuity of previous studies conducted at a local scale in the same region, SSM maps are here processed over the whole AMMA Gourma mesoscale site at 1 km resolution scale. Overall, the generated maps are found to be in good agreement with field data, EPSAT-SG (Estimation des Pluies par SATellite – Second Generation) rainfall estimates and ERS (European Remote Sensing) Wind Scatterometer (WSC) SSM products. The present study shows that the spatial pattern of SSM can be realistically estimated at a kilometric scale. The resulting SSM maps are expected to provide valuable information for initialisation of land surface models and the estimation of the spatial distribution of radiative fluxes. Particularly, SSM maps could help to desaggregate low-resolution products such as those derived from WSC data.},
	number = {2},
	urldate = {2014-06-13},
	journal = {Hydrol. Earth Syst. Sci.},
	author = {Baup, F. and Mougin, E. and de Rosnay, P. and Hiernaux, P. and Frappart, F. and Frison, P. L. and Zribi, M. and Viarre, J.},
	month = feb,
	year = {2011},
	keywords = {AMMA-CATCH, Mali},
	pages = {603--616},
}

@article{hein_desertification_2011,
	title = {Desertification in the {Sahel}: {Towards} better accounting for ecosystem dynamics in the interpretation of remote sensing images},
	volume = {75},
	issn = {01401963},
	shorttitle = {Desertification in the {Sahel}},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0140196311001546},
	doi = {10.1016/j.jaridenv.2011.05.002},
	language = {en},
	number = {11},
	urldate = {2014-06-13},
	journal = {Journal of Arid Environments},
	author = {Hein, L. and de Ridder, N. and Hiernaux, P. and Leemans, R. and de Wit, A. and Schaepman, M.},
	month = nov,
	year = {2011},
	keywords = {AMMA-CATCH},
	pages = {1164--1172},
}

@article{sjostrom_exploring_2011,
	title = {Exploring the potential of {MODIS} {EVI} for modeling gross primary production across {African} ecosystems},
	volume = {115},
	issn = {00344257},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425710003597},
	doi = {10.1016/j.rse.2010.12.013},
	language = {en},
	number = {4},
	urldate = {2014-06-13},
	journal = {Remote Sensing of Environment},
	author = {Sjöström, M. and Ardö, J. and Arneth, A. and Boulain, N. and Cappelaere, B. and Eklundh, L. and de Grandcourt, A. and Kutsch, W.L. and Merbold, L. and Nouvellon, Y.},
	month = apr,
	year = {2011},
	keywords = {AMMA-CATCH},
	pages = {1081--1089},
}

@article{abdou_diurnal_2010,
	title = {The diurnal cycle of lower boundary-layer wind in the {West} {African} monsoon},
	volume = {136},
	issn = {00359009},
	url = {http://doi.wiley.com/10.1002/qj.536},
	doi = {10.1002/qj.536},
	language = {en},
	number = {S1},
	urldate = {2014-06-13},
	journal = {Quarterly Journal of the Royal Meteorological Society},
	author = {Abdou, Kassimou and Parker, Douglas J. and Brooks, Barbara and Kalthoff, Norbert and Lebel, Thierry},
	month = jan,
	year = {2010},
	keywords = {AMMA-CATCH},
	pages = {66--76},
}

@article{adon_long_2010,
	title = {Long term measurements of sulfur dioxide, nitrogen dioxide, ammonia, nitric acid and ozone in {Africa} using passive samplers},
	volume = {10},
	issn = {1680-7324},
	url = {http://www.atmos-chem-phys.net/10/7467/2010/},
	doi = {10.5194/acp-10-7467-2010},
	language = {en},
	number = {15},
	urldate = {2014-06-13},
	journal = {Atmospheric Chemistry and Physics},
	author = {Adon, M. and Galy-Lacaux, C. and Yoboué, V. and Delon, C. and Lacaux, J. P. and Castera, P. and Gardrat, E. and Pienaar, J. and Al Ourabi, H. and Laouali, D. and Diop, B. and Sigha-Nkamdjou, L. and Akpo, A. and Tathy, J. P. and Lavenu, F. and Mougin, E.},
	month = aug,
	year = {2010},
	keywords = {AMMA-CATCH},
	pages = {7467--7487},
}

@article{bain_observations_2010,
	title = {Observations of the {Nocturnal} {Boundary} {Layer} {Associated} with the {West} {African} {Monsoon}},
	volume = {138},
	issn = {0027-0644, 1520-0493},
	url = {http://journals.ametsoc.org/doi/abs/10.1175/2010MWR3287.1},
	doi = {10.1175/2010MWR3287.1},
	language = {en},
	number = {8},
	urldate = {2014-06-13},
	journal = {Monthly Weather Review},
	author = {Bain, Caroline L. and Parker, Douglas J. and Taylor, Christopher M. and Kergoat, Laurent and Guichard, Françoise},
	month = aug,
	year = {2010},
	keywords = {AMMA-CATCH},
	pages = {3142--3156},
}

@article{barthe_multi-scale_2010,
	title = {Multi-scale analysis of the 25-27 {July} 2006 convective period over {Niamey}: {Comparison} between {Doppler} radar observations and simulations},
	volume = {136},
	issn = {00359009},
	shorttitle = {Multi-scale analysis of the 25-27 {July} 2006 convective period over {Niamey}},
	url = {http://doi.wiley.com/10.1002/qj.539},
	doi = {10.1002/qj.539},
	language = {en},
	number = {S1},
	urldate = {2014-06-13},
	journal = {Quarterly Journal of the Royal Meteorological Society},
	author = {Barthe, Christelle and Asencio, Nicole and Lafore, Jean-Philippe and Chong, Michel and Campistron, Bernard and Cazenave, Frédéric},
	month = jan,
	year = {2010},
	keywords = {AMMA-CATCH},
	pages = {190--208},
}

@article{boone_evaluation_2010,
	title = {Evaluation of the {WAMME} model surface fluxes using results from the {AMMA} land-surface model intercomparison project},
	volume = {35},
	issn = {0930-7575, 1432-0894},
	url = {http://link.springer.com/10.1007/s00382-009-0653-1},
	doi = {10.1007/s00382-009-0653-1},
	language = {en},
	number = {1},
	urldate = {2014-06-13},
	journal = {Climate Dynamics},
	author = {Boone, Aaron Anthony and Poccard-Leclercq, Isabelle and Xue, Yongkang and Feng, Jinming and Rosnay, Patricia},
	month = jul,
	year = {2010},
	keywords = {AMMA-CATCH},
	pages = {127--142},
}

@article{delon_atmospheric_2010,
	title = {Atmospheric nitrogen budget in {Sahelian} dry savannas},
	volume = {10},
	issn = {1680-7324},
	url = {http://www.atmos-chem-phys.net/10/2691/2010/},
	doi = {10.5194/acp-10-2691-2010},
	language = {en},
	number = {6},
	urldate = {2014-06-13},
	journal = {Atmospheric Chemistry and Physics},
	author = {Delon, C. and Galy-Lacaux, C. and Boone, A. and Liousse, C. and Serça, D. and Adon, M. and Diop, B. and Akpo, A. and Lavenu, F. and Mougin, E. and Timouk, F.},
	month = mar,
	year = {2010},
	keywords = {AMMA-CATCH},
	pages = {2691--2708},
}

@article{panthou_characterising_2014,
	title = {Characterising the space–time structure of rainfall in the {Sahel} with a view to estimating {IDAF} curves},
	volume = {18},
	issn = {1607-7938},
	url = {http://www.hydrol-earth-syst-sci.net/18/5093/2014/},
	doi = {10.5194/hess-18-5093-2014},
	language = {en},
	number = {12},
	urldate = {2015-05-04},
	journal = {Hydrology and Earth System Sciences},
	author = {Panthou, G. and Vischel, T. and Lebel, T. and Quantin, G. and Molinié, G.},
	month = dec,
	year = {2014},
	keywords = {AMMA-CATCH, PHYREV},
	pages = {5093--5107},
}

@article{tremoy_clustering_2014,
	title = {Clustering mesoscale convective systems with laser-based water vapor δ 18-{O} monitoring in {Niamey} ({Niger})},
	volume = {119},
	issn = {2169897X},
	url = {http://doi.wiley.com/10.1002/2013JD020968},
	doi = {10.1002/2013JD020968},
	language = {en},
	number = {9},
	urldate = {2015-05-04},
	journal = {Journal of Geophysical Research: Atmospheres},
	author = {Tremoy, Guillaume and Vimeux, Françoise and Soumana, Salifou and Souley, Ide and Risi, Camille and Favreau, Guillaume and Oï, Monique},
	month = may,
	year = {2014},
	keywords = {AMMA-CATCH, Niger, AO},
	pages = {5079--5103},
}

@article{ibrahim_long-term_2014,
	title = {Long-term increase in diffuse groundwater recharge following expansion of rainfed cultivation in the {Sahel}, {West} {Africa}},
	volume = {22},
	issn = {1431-2174, 1435-0157},
	url = {http://link.springer.com/10.1007/s10040-014-1143-z},
	doi = {10.1007/s10040-014-1143-z},
	language = {en},
	number = {6},
	urldate = {2015-05-04},
	journal = {Hydrogeology Journal},
	author = {Ibrahim, Maïmouna and Favreau, Guillaume and Scanlon, Bridget R. and Seidel, Jean Luc and Le Coz, Mathieu and Demarty, Jérôme and Cappelaere, Bernard},
	month = sep,
	year = {2014},
	keywords = {AMMA-CATCH},
	pages = {1293--1305},
}

@article{diedhiou_mean_2010,
	title = {Mean kinematic characteristics of synoptic easterly disturbances over the {Atlantic}},
	volume = {27},
	issn = {0256-1530, 1861-9533},
	url = {http://link.springer.com/10.1007/s00376-009-9092-5},
	doi = {10.1007/s00376-009-9092-5},
	language = {en},
	number = {3},
	urldate = {2014-06-13},
	journal = {Advances in Atmospheric Sciences},
	author = {Diedhiou, Arona and Machado, Luiz A. T. and Laurent, Henri},
	month = may,
	year = {2010},
	keywords = {AMMA-CATCH},
	pages = {483--499},
}

@article{gosset_rain_2010,
	title = {Rain drop size distribution variability and impact on {X}-band polarimetric radar retrieval: {Results} from the {AMMA} campaign in {Benin}},
	volume = {136},
	issn = {00359009},
	shorttitle = {Rain drop size distribution variability and impact on {X}-band polarimetric radar retrieval},
	url = {http://doi.wiley.com/10.1002/qj.556},
	doi = {10.1002/qj.556},
	language = {en},
	number = {S1},
	urldate = {2014-06-13},
	journal = {Quarterly Journal of the Royal Meteorological Society},
	author = {Gosset, Marielle and Zahiri, Eric-Pascal and Moumouni, Sounmaila},
	month = jan,
	year = {2010},
	keywords = {AMMA-CATCH, benin},
	pages = {243--256},
}

@article{gruhier_soil_2010,
	title = {Soil moisture active and passive microwave products: intercomparison and evaluation over a {Sahelian} site},
	volume = {14},
	issn = {1607-7938},
	shorttitle = {Soil moisture active and passive microwave products},
	url = {http://www.hydrol-earth-syst-sci.net/14/141/2010/},
	doi = {10.5194/hess-14-141-2010},
	language = {en},
	number = {1},
	urldate = {2014-06-13},
	journal = {Hydrology and Earth System Sciences},
	author = {Gruhier, C. and de Rosnay, P. and Hasenauer, S. and Holmes, T. and de Jeu, R. and Kerr, Y. and Mougin, E. and Njoku, E. and Timouk, F. and Wagner, W. and Zribi, M.},
	month = jan,
	year = {2010},
	keywords = {AMMA-CATCH},
	pages = {141--156},
}

@article{mangiarotti_vegetation_2010,
	title = {The vegetation cycle in {West} {Africa} from {AVHRR}–{NDVI} data: {Horizons} of predictability versus spatial scales},
	volume = {114},
	issn = {00344257},
	shorttitle = {The vegetation cycle in {West} {Africa} from {AVHRR}–{NDVI} data},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425710001239},
	doi = {10.1016/j.rse.2010.04.010},
	language = {en},
	number = {9},
	urldate = {2014-06-13},
	journal = {Remote Sensing of Environment},
	author = {Mangiarotti, S. and Mazzega, P. and Hiernaux, P. and Mougin, E.},
	month = sep,
	year = {2010},
	keywords = {AMMA-CATCH},
	pages = {2036--2047},
}

@article{monsivais-huertero_microwave_2010,
	title = {Microwave electromagnetic modelling of {Sahelian} grassland},
	volume = {31},
	issn = {0143-1161, 1366-5901},
	url = {http://www.tandfonline.com/doi/abs/10.1080/01431160902926582},
	doi = {10.1080/01431160902926582},
	language = {en},
	number = {7},
	urldate = {2014-06-13},
	journal = {International Journal of Remote Sensing},
	author = {Monsivais-Huertero, A. and Chenerie, I. and Sarabandi, K. and Baup, F. and Mougin, E.},
	month = apr,
	year = {2010},
	keywords = {AMMA-CATCH},
	pages = {1915--1942},
}

@article{roca_comparing_2010,
	title = {Comparing {Satellite} and {Surface} {Rainfall} {Products} over {West} {Africa} at {Meteorologically} {Relevant} {Scales} during the {AMMA} {Campaign} {Using} {Error} {Estimates}},
	volume = {49},
	issn = {1558-8424, 1558-8432},
	url = {http://journals.ametsoc.org/doi/abs/10.1175/2009JAMC2318.1},
	doi = {10.1175/2009JAMC2318.1},
	language = {en},
	number = {4},
	urldate = {2014-06-13},
	journal = {Journal of Applied Meteorology and Climatology},
	author = {Roca, Rémy and Chambon, Philippe and Jobard, Isabelle and Kirstetter, Pierre-Emmanuel and Gosset, Marielle and Bergès, Jean Claude},
	month = apr,
	year = {2010},
	keywords = {AMMA-CATCH},
	pages = {715--731},
}

@article{wolters_effects_2010,
	title = {Effects of soil moisture gradients on the path and the intensity of a {West} {African} squall line},
	volume = {136},
	issn = {00359009},
	url = {http://doi.wiley.com/10.1002/qj.712},
	doi = {10.1002/qj.712},
	language = {en},
	number = {653},
	urldate = {2014-06-13},
	journal = {Quarterly Journal of the Royal Meteorological Society},
	author = {Wolters, Dirk and van Heerwaarden, Chiel C. and de Arellano, Jordi Vilà-Guerau and Cappelaere, Bernard and Ramier, David},
	month = oct,
	year = {2010},
	keywords = {AMMA-CATCH},
	pages = {2162--2175},
}

@article{decharme_new_2009,
	title = {A {New} {Land} {Surface} {Hydrology} within the {Noah}-{WRF} {Land}-{Atmosphere} {Mesoscale} {Model} {Applied} to {Semiarid} {Environment}: {Evaluation} over the {Dantiandou} {Kori} ({Niger})},
	volume = {2009},
	issn = {1687-9309, 1687-9317},
	shorttitle = {A {New} {Land} {Surface} {Hydrology} within the {Noah}-{WRF} {Land}-{Atmosphere} {Mesoscale} {Model} {Applied} to {Semiarid} {Environment}},
	url = {http://www.hindawi.com/journals/amete/2009/731874/},
	doi = {10.1155/2009/731874},
	language = {en},
	urldate = {2014-06-13},
	journal = {Advances in Meteorology},
	author = {Decharme, B. and Ottlé, C. and Saux-Picart, S. and Boulain, N. and Cappelaere, B. and Ramier, D. and Zribi, M.},
	year = {2009},
	keywords = {AMMA-CATCH, niger},
	pages = {1--13},
}

@article{flamant_impact_2009,
	title = {The impact of a mesoscale convective system cold pool on the northward propagation of the intertropical discontinuity over {West} {Africa}},
	volume = {135},
	issn = {00359009, 1477870X},
	url = {http://doi.wiley.com/10.1002/qj.357},
	doi = {10.1002/qj.357},
	language = {en},
	number = {638},
	urldate = {2014-06-13},
	journal = {Quarterly Journal of the Royal Meteorological Society},
	author = {Flamant, C. and Knippertz, P. and Parker, D. J. and Chaboureau, J.-P. and Lavaysse, C. and Agusti-Panareda, A. and Kergoat, L.},
	month = jan,
	year = {2009},
	keywords = {AMMA-CATCH, ao},
	pages = {139--159},
}

@article{leroux_relationship_2009,
	title = {On the {Relationship} between {African} {Easterly} {Waves} and the {African} {Easterly} {Jet}},
	volume = {66},
	issn = {0022-4928, 1520-0469},
	url = {http://journals.ametsoc.org/doi/abs/10.1175/2009JAS2988.1},
	doi = {10.1175/2009JAS2988.1},
	language = {en},
	number = {8},
	urldate = {2014-06-13},
	journal = {Journal of the Atmospheric Sciences},
	author = {Leroux, Stephanie and Hall, Nicholas M. J.},
	month = aug,
	year = {2009},
	keywords = {AMMA-CATCH},
	pages = {2303--2316},
}

@article{ayantunde_botanical_2008,
	title = {Botanical {Knowledge} and its {Differentiation} by {Age}, {Gender} and {Ethnicity} in {Southwestern} {Niger}},
	volume = {36},
	issn = {0300-7839, 1572-9915},
	url = {http://link.springer.com/10.1007/s10745-008-9200-7},
	doi = {10.1007/s10745-008-9200-7},
	language = {en},
	number = {6},
	urldate = {2014-06-13},
	journal = {Human Ecology},
	author = {Ayantunde, Augustine A. and Briejer, Mirjam and Hiernaux, Pierre and Udo, Henk M. J. and Tabo, Ramadjita},
	month = dec,
	year = {2008},
	keywords = {AMMA-CATCH, niger},
	pages = {881--889},
}

@article{gruhier_evaluation_2008,
	title = {Evaluation of {AMSR}-{E} soil moisture product based on ground measurements over temperate and semi-arid regions},
	volume = {35},
	issn = {0094-8276},
	url = {http://doi.wiley.com/10.1029/2008GL033330},
	doi = {10.1029/2008GL033330},
	language = {en},
	number = {10},
	urldate = {2014-06-13},
	journal = {Geophysical Research Letters},
	author = {Gruhier, C. and de Rosnay, P. and Kerr, Y. and Mougin, E. and Ceschia, E. and Calvet, J.-C. and Richaume, P.},
	month = may,
	year = {2008},
	keywords = {AMMA-CATCH},
}

@article{janicot_large-scale_2008,
	title = {Large-scale overview of the summer monsoon over {West} {Africa} during the {AMMA} field experiment in 2006},
	volume = {26},
	issn = {1432-0576},
	url = {http://www.ann-geophys.net/26/2569/2008/},
	doi = {10.5194/angeo-26-2569-2008},
	language = {en},
	number = {9},
	urldate = {2014-06-13},
	journal = {Annales Geophysicae},
	author = {Janicot, S. and Thorncroft, C. D. and Ali, A. and Asencio, N. and Berry, G. and Bock, O. and Bourles, B. and Caniaux, G. and Chauvin, F. and Deme, A. and Kergoat, L. and Lafore, J.-P. and Lavaysse, C. and Lebel, T. and Marticorena, B. and Mounier, F. and Nedelec, P. and Redelsperger, J.-L. and Ravegnani, F. and Reeves, C. E. and Roca, R. and de Rosnay, P. and Schlager, H. and Sultan, B. and Tomasini, M. and Ulanovsky, A. and {ACMAD forecasters team}},
	month = sep,
	year = {2008},
	keywords = {AMMA-CATCH, ao},
	pages = {2569--2595},
}

@article{kamagate_processus_2008,
	title = {Processus hydrogéochimiques et séparation d’hydrogrammes de crue sur un bassin versant en milieu soudano-tropical de socle au {Bénin} ({Donga}, haute vallée de l’{Ouémé})},
	volume = {21},
	issn = {0992-7158, 1718-8598},
	url = {http://id.erudit.org/iderudit/018782ar},
	doi = {10.7202/018782ar},
	language = {fr},
	number = {3},
	urldate = {2014-06-13},
	journal = {Revue des sciences de l'eau},
	author = {Kamagaté, Bamory and Séguis, Luc and Goné Droh, Lanciné and Favreau, Guillaume and Koffi, Kouadio},
	year = {2008},
	keywords = {AMMA-CATCH, benin},
	pages = {363},
}

@article{mangiarotti_evolutionary_2008,
	title = {Evolutionary bi-objective optimization of a semi-arid vegetation dynamics model with {NDVI} and σ0 satellite data},
	volume = {112},
	issn = {00344257},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425707003288},
	doi = {10.1016/j.rse.2007.03.030},
	language = {en},
	number = {4},
	urldate = {2014-06-13},
	journal = {Remote Sensing of Environment},
	author = {Mangiarotti, S and Mazzega, P and Jarlan, L and Mougin, E and Baup, F and Demarty, J},
	month = apr,
	year = {2008},
	keywords = {AMMA-CATCH, mali},
	pages = {1365--1380},
}

@article{gascon_influence_2015,
	title = {Influence of rainfall space-time variability over the {Ouémé} basin in {Benin}},
	volume = {368},
	issn = {2199-899X},
	url = {http://www.proc-iahs.net/368/102/2015/},
	doi = {10.5194/piahs-368-102-2015},
	language = {en},
	urldate = {2015-06-26},
	journal = {Proceedings of the International Association of Hydrological Sciences},
	author = {Gascon, T. and Vischel, T. and Lebel, T. and Quantin, G. and Pellarin, T. and Quatela, V. and Leroux, D. and Galle, S.},
	month = may,
	year = {2015},
	keywords = {AMMA-CATCH, Benin, PHYREV},
	pages = {102--107},
}

@article{delon_modelling_2015,
	title = {Modelling the effect of soil moisture and organic matter degradation on biogenic {NO} emissions from soils in {Sahel} rangeland ({Mali})},
	volume = {12},
	issn = {1726-4189},
	url = {http://www.biogeosciences.net/12/3253/2015/},
	doi = {10.5194/bg-12-3253-2015},
	language = {en},
	number = {11},
	urldate = {2015-07-22},
	journal = {Biogeosciences},
	author = {Delon, C. and Mougin, E. and Serça, D. and Grippa, M. and Hiernaux, P. and Diawara, M. and Galy-Lacaux, C. and Kergoat, L.},
	month = jun,
	year = {2015},
	keywords = {AMMA-CATCH, ext1, Mali},
	pages = {3253--3272},
}

@article{frappart_radar_2015,
	title = {Radar altimetry backscattering signatures at {Ka}, {Ku}, {C}, and {S} bands over {West} {Africa}},
	issn = {14747065},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S147470651500039X},
	doi = {10.1016/j.pce.2015.05.001},
	language = {en},
	urldate = {2015-07-22},
	journal = {Physics and Chemistry of the Earth, Parts A/B/C},
	author = {Frappart, F. and Fatras, C. and Mougin, E. and Marieu, V. and Diepkilé, A.T. and Blarel, F. and Borderies, P.},
	month = may,
	year = {2015},
	keywords = {AMMA-CATCH, ext1, AO, Radar},
}

@article{veenendaal_structural_2015,
	title = {Structural, physiognomic and above-ground biomass variation in savanna–forest transition zones on three continents – how different are co-occurring savanna and forest formations?},
	volume = {12},
	issn = {1726-4189},
	url = {http://www.biogeosciences.net/12/2927/2015/},
	doi = {10.5194/bg-12-2927-2015},
	language = {en},
	number = {10},
	urldate = {2015-07-22},
	journal = {Biogeosciences},
	author = {Veenendaal, E. M. and Torello-Raventos, M. and Feldpausch, T. R. and Domingues, T. F. and Gerard, F. and Schrodt, F. and Saiz, G. and Quesada, C. A. and Djagbletey, G. and Ford, A. and Kemp, J. and Marimon, B. S. and Marimon-Junior, B. H. and Lenza, E. and Ratter, J. A. and Maracahipes, L. and Sasaki, D. and Sonké, B. and Zapfack, L. and Villarroel, D. and Schwarz, M. and Yoko Ishida, F. and Gilpin, M. and Nardoto, G. B. and Affum-Baffoe, K. and Arroyo, L. and Bloomfield, K. and Ceca, G. and Compaore, H. and Davies, K. and Diallo, A. and Fyllas, N. M. and Gignoux, J. and Hien, F. and Johnson, M. and Mougin, E. and Hiernaux, P. and Killeen, T. and Metcalfe, D. and Miranda, H. S. and Steininger, M. and Sykora, K. and Bird, M. I. and Grace, J. and Lewis, S. and Phillips, O. L. and Lloyd, J.},
	month = may,
	year = {2015},
	keywords = {Sahel, AMMA-CATCH, ext1, AO},
	pages = {2927--2951},
}

@article{leauthaud_revisiting_2015,
	title = {Revisiting historical climatic signals to better explore the future: prospects of water cycle changes in {Central} {Sahel}},
	volume = {371},
	issn = {2199-899X},
	shorttitle = {Revisiting historical climatic signals to better explore the future},
	url = {http://www.proc-iahs.net/371/195/2015/},
	doi = {10.5194/piahs-371-195-2015},
	language = {en},
	urldate = {2015-07-22},
	journal = {Proceedings of the International Association of Hydrological Sciences},
	author = {Leauthaud, C. and Demarty, J. and Cappelaere, B. and Grippa, M. and Kergoat, L. and Velluet, C. and Guichard, F. and Mougin, E. and Chelbi, S. and Sultan, B.},
	month = jun,
	year = {2015},
	keywords = {Sahel, AMMA-CATCH, Niger, Mali, ACL},
	pages = {195--201},
}

@article{parker_amma_2008,
	title = {The {Amma} {Radiosonde} {Program} and its {Implications} for the {Future} of {Atmospheric} {Monitoring} {Over} {Africa}},
	volume = {89},
	issn = {0003-0007, 1520-0477},
	url = {http://journals.ametsoc.org/doi/abs/10.1175/2008BAMS2436.1},
	doi = {10.1175/2008BAMS2436.1},
	language = {en},
	number = {7},
	urldate = {2014-06-13},
	journal = {Bulletin of the American Meteorological Society},
	author = {Parker, Douglas J. and Fink, Andreas and Janicot, Serge and Ngamini, Jean-Blaise and Douglas, Michael and Afiesimama, Ernest and Agusti-Panareda, Anna and Beljaars, Anton and Dide, Francis and Diedhiou, Arona and Lebel, Thierry and Polcher, Jan and Redelsperger, Jean-Luc and Thorncroft, Chris and Ato Wilson, George},
	month = jul,
	year = {2008},
	keywords = {AMMA-CATCH, ao},
	pages = {1015--1027},
}

@article{zahiri_use_2008,
	title = {Use of a {Radar} {Simulator} on the {Output} {Fields} from a {Numerical} {Mesoscale} {Model} to {Analyze} {X}-{Band} {Rain} {Estimators}},
	volume = {25},
	issn = {0739-0572, 1520-0426},
	url = {http://journals.ametsoc.org/doi/abs/10.1175/2007JTECHA933.1},
	doi = {10.1175/2007JTECHA933.1},
	language = {en},
	number = {3},
	urldate = {2014-06-13},
	journal = {Journal of Atmospheric and Oceanic Technology},
	author = {Zahiri, E-P. and Gosset, M. and Lafore, J-P. and Gouget, V.},
	month = mar,
	year = {2008},
	keywords = {AMMA-CATCH, benin},
	pages = {341--367},
}

@article{ayantunde_herders_2007,
	title = {Herders’ {Perceptions} on {Ruminant} {Livestock} {Breeds} and {Breeding} {Management} in {Southwestern} {Niger}},
	volume = {35},
	issn = {0300-7839, 1572-9915},
	url = {http://link.springer.com/10.1007/s10745-006-9049-6},
	doi = {10.1007/s10745-006-9049-6},
	language = {en},
	number = {1},
	urldate = {2014-06-13},
	journal = {Human Ecology},
	author = {Ayantunde, Augustine A. and Kango, Moctar and Hiernaux, Pierre and Udo, Henk M. J. and Tabo, Ramadjita},
	month = feb,
	year = {2007},
	keywords = {AMMA-CATCH, niger},
	pages = {139--149},
}

@article{ayantunde_implications_2008,
	title = {Implications of restricted access to grazing by cattle in wet season in the {Sahel}},
	volume = {72},
	issn = {01401963},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0140196307001747},
	doi = {10.1016/j.jaridenv.2007.06.006},
	language = {en},
	number = {4},
	urldate = {2014-06-13},
	journal = {Journal of Arid Environments},
	author = {Ayantunde, A.A. and Fernández-Rivera, S. and Hiernaux, P.H. and Tabo, R.},
	month = apr,
	year = {2008},
	keywords = {AMMA-CATCH, ao},
	pages = {523--533},
}

@article{baup_radar_2007,
	title = {Radar {Signatures} of {Sahelian} {Surfaces} in {Mali} {Using} {ENVISAT}-{ASAR} {Data}},
	volume = {45},
	issn = {0196-2892},
	doi = {10.1109/TGRS.2007.893824},
	abstract = {This paper presents an analysis of ENSIVAT advanced synthetic aperture radar data acquired over a Sahelian region located in Mali, West Africa. The considered period is 2004-2005 and includes two rainy seasons. Emphasis is put on two ScanSAR modes, namely, the global monitoring (GM) and the wide swath (WS) modes characterized by spatial resolutions of about 1 km and 150 m, respectively. Results show that the WS mode offers better performance in terms of radiometric resolution, radiometric stability, and speckle reduction than the GM mode. The latter is more appropriate for studies at large scale ({\textbackslash}textgreater 10 times 10 km). In both modes, pronounced angular and temporal signatures are observed for most soil surfaces, and azimuthal effects are observed on markedly orientated rocky surfaces. In contrast, polarization differences (VV/HH) are small during the dry season except on flat loamy soil surfaces. Finally, a relationship is observed between the normalized WS backscattering signal at HH polarization and the surface soil moisture of sandy soils.},
	number = {7},
	journal = {IEEE Transactions on Geoscience and Remote Sensing},
	author = {Baup, F. and Mougin, E. and Hiernaux, P. and Lopes, A. and De Rosnay, P. and Chenerie, I.},
	month = jul,
	year = {2007},
	keywords = {West Africa, Africa, Sahel, Soil moisture, Stability, Spatial resolution, AMMA-CATCH, radar, Mali, Radar, monitoring, soil, synthetic aperture radar, wide swath mode, AD 2004 to 2005, advanced synthetic aperture radar, Advanced Synthetic Aperture Radar (ASAR), data analysis, ENVISAT, ENVISAT-ASAR data, geophysical techniques, global monitoring, global monitoring mode, Large-scale systems, Polarization, radar signatures, radiometric resolution, radiometric stability, radiometry, Sahelian surfaces, ScanSAR modes, Speckle, speckle reduction, wide swath},
	pages = {2354--2363},
}

@article{baup_surface_2007,
	title = {Surface soil moisture estimation over the {AMMA} {Sahelian} site in {Mali} using {ENVISAT}/{ASAR} data},
	volume = {109},
	issn = {00344257},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425707000521},
	doi = {10.1016/j.rse.2007.01.015},
	language = {en},
	number = {4},
	urldate = {2014-06-13},
	journal = {Remote Sensing of Environment},
	author = {Baup, F. and Mougin, E. and de Rosnay, P. and Timouk, F. and Chênerie, I.},
	month = aug,
	year = {2007},
	keywords = {AMMA-CATCH, radar, Mali},
	pages = {473--481},
}

@article{boulain_changing_2007,
	title = {Changing scale in ecological modelling: {A} bottom up approach with an individual based vegetation model},
	volume = {203},
	issn = {03043800},
	shorttitle = {Changing scale in ecological modelling},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0304380006005795},
	doi = {10.1016/j.ecolmodel.2006.11.024},
	language = {en},
	number = {3-4},
	urldate = {2014-06-13},
	journal = {Ecological Modelling},
	author = {Boulain, Nicolas and Simioni, Guillaume and Gignoux, Jacques},
	month = may,
	year = {2007},
	keywords = {AMMA-CATCH, niger},
	pages = {257--269},
}

@article{flamant_airborne_2007,
	title = {Airborne observations of the impact of a convective system on the planetary boundary layer thermodynamics and aerosol distribution in the inter-tropical discontinuity region of the {West} {African} {Monsoon}},
	volume = {133},
	issn = {00359009, 1477870X},
	url = {http://doi.wiley.com/10.1002/qj.97},
	doi = {10.1002/qj.97},
	language = {en},
	number = {626},
	urldate = {2014-06-13},
	journal = {Quarterly Journal of the Royal Meteorological Society},
	author = {Flamant, C. and Chaboureau, J.-P. and Parker, D. J. and Taylor, C. M. and Cammas, J.-P. and Bock, O. and Timouk, F. and Pelon, J.},
	month = jul,
	year = {2007},
	keywords = {AMMA-CATCH, AO},
	pages = {1175--1189},
}

@article{zribi_soil_2007,
	title = {Soil moisture mapping based on {ASAR}/{ENVISAT} radar data over a {Sahelian} region},
	volume = {28},
	issn = {0143-1161, 1366-5901},
	url = {http://www.tandfonline.com/doi/abs/10.1080/01431160601009680},
	doi = {10.1080/01431160601009680},
	language = {en},
	number = {16},
	urldate = {2014-06-13},
	journal = {International Journal of Remote Sensing},
	author = {Zribi, M. and Saux‐Picart, S. and André, C. and Descroix, L. and Ottlé, C. and Kallel, A.},
	month = aug,
	year = {2007},
	keywords = {AMMA-CATCH, niger},
	pages = {3547--3565},
}

@article{dorigo_evaluation_2015,
	title = {Evaluation of the {ESA} {CCI} soil moisture product using ground-based observations},
	volume = {162},
	issn = {00344257},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425714002727},
	doi = {10.1016/j.rse.2014.07.023},
	language = {en},
	urldate = {2015-07-22},
	journal = {Remote Sensing of Environment},
	author = {Dorigo, W.A. and Gruber, A. and De Jeu, R.A.M. and Wagner, W. and Stacke, T. and Loew, A. and Albergel, C. and Brocca, L. and Chung, D. and Parinussa, R.M. and Kidd, R.},
	month = jun,
	year = {2015},
	keywords = {AMMA-CATCH, ext1, extérieur, AO, ISMN},
	pages = {380--395},
}

@article{boulain_water_2009,
	title = {Water balance and vegetation change in the {Sahel}: {A} case study at the watershed scale with an eco-hydrological model},
	volume = {73},
	issn = {01401963},
	shorttitle = {Water balance and vegetation change in the {Sahel}},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0140196309001517},
	doi = {10.1016/j.jaridenv.2009.05.008},
	language = {en},
	number = {12},
	urldate = {2014-06-13},
	journal = {Journal of Arid Environments},
	author = {Boulain, N. and Cappelaere, B. and Séguis, L. and Favreau, G. and Gignoux, J.},
	month = dec,
	year = {2009},
	keywords = {AMMA-CATCH, niger},
	pages = {1125--1135},
}

@article{balme_annees_2006,
	title = {Années sèches et années humides au {Sahel}: quo vadimus?},
	volume = {51},
	issn = {0262-6667, 2150-3435},
	shorttitle = {Années sèches et années humides au {Sahel}},
	url = {http://www.tandfonline.com/doi/abs/10.1623/hysj.51.2.254},
	doi = {10.1623/hysj.51.2.254},
	language = {en},
	number = {2},
	urldate = {2014-06-13},
	journal = {Hydrological Sciences Journal},
	author = {Balme, Maud and Lebel, Thierry and Amani, Abou},
	month = apr,
	year = {2006},
	keywords = {AMMA-CATCH, AO},
	pages = {254--271},
}

@article{boulain_hydrologic_2006,
	title = {Hydrologic and land use impacts on vegetation growth and {NPP} at the watershed scale in a semi-arid environment},
	volume = {6},
	issn = {1436-3798, 1436-378X},
	url = {http://link.springer.com/10.1007/s10113-006-0014-0},
	doi = {10.1007/s10113-006-0014-0},
	language = {en},
	number = {3},
	urldate = {2014-06-13},
	journal = {Regional Environmental Change},
	author = {Boulain, N. and Cappelaere, B. and Séguis, L. and Gignoux, J. and Peugeot, C.},
	month = may,
	year = {2006},
	keywords = {AMMA-CATCH, Niger},
	pages = {147--156},
}

@article{jamnadass_population_2006,
	title = {Population genetic responses of wild forage species to grazing along a rainfall gradient in the {Sahel}: {A} study combining phenotypic and molecular analyses},
	volume = {151},
	issn = {0014-2336, 1573-5060},
	shorttitle = {Population genetic responses of wild forage species to grazing along a rainfall gradient in the {Sahel}},
	url = {http://link.springer.com/10.1007/s10681-006-9175-7},
	doi = {10.1007/s10681-006-9175-7},
	language = {en},
	number = {3},
	urldate = {2014-06-13},
	journal = {Euphytica},
	author = {Jamnadass, R. and Mace, E. S. and Hiernaux, P. and Muchugi, A. and Hanson, J.},
	month = nov,
	year = {2006},
	keywords = {AMMA-CATCH, AO},
	pages = {431--445},
}

@article{lavaysse_african_2006,
	title = {African {Easterly} {Waves} and convective activity in wet and dry sequences of the {West} {African} {Monsoon}},
	volume = {27},
	issn = {0930-7575, 1432-0894},
	url = {http://link.springer.com/10.1007/s00382-006-0137-5},
	doi = {10.1007/s00382-006-0137-5},
	language = {en},
	number = {2-3},
	urldate = {2014-06-13},
	journal = {Climate Dynamics},
	author = {Lavaysse, Christophe and Diedhiou, Arona and Laurent, Henri and Lebel, Thierry},
	month = aug,
	year = {2006},
	keywords = {AMMA-CATCH, AO},
	pages = {319--332},
}

@article{leduc_comment_2006,
	title = {Comment on “{Estimating} groundwater mixing ratios and their uncertainties using a statistical multi parameter approach” by {Rueedi}, {J}., {Purtschert}, {R}., {Beyerle}, {U}., {Alberich}, {C}., {Kipfer}, {R}. {J}. {Hydrol}., 2005, 305: 1–14},
	volume = {318},
	issn = {00221694},
	shorttitle = {Comment on “{Estimating} groundwater mixing ratios and their uncertainties using a statistical multi parameter approach” by {Rueedi}, {J}., {Purtschert}, {R}., {Beyerle}, {U}., {Alberich}, {C}., {Kipfer}, {R}. {J}. {Hydrol}., 2005, 305},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0022169405003082},
	doi = {10.1016/j.jhydrol.2005.06.018},
	language = {en},
	number = {1-4},
	urldate = {2014-06-13},
	journal = {Journal of Hydrology},
	author = {Leduc, C. and Favreau, G. and Guero, A. and Daddy Gaoh, A.},
	month = mar,
	year = {2006},
	keywords = {AMMA-CATCH, Niger},
	pages = {3--6},
}

@article{messager_influence_2006,
	title = {Influence of observed and {RCM}-simulated precipitation on the water discharge over the {Sirba} basin, {Burkina} {Faso}/{Niger}},
	volume = {27},
	issn = {0930-7575, 1432-0894},
	url = {http://link.springer.com/10.1007/s00382-006-0131-y},
	doi = {10.1007/s00382-006-0131-y},
	language = {en},
	number = {2-3},
	urldate = {2014-06-13},
	journal = {Climate Dynamics},
	author = {Messager, Christophe and Gallée, Hubert and Brasseur, Olivier and Cappelaere, Bernard and Peugeot, Christophe and Séguis, Luc and Vauclin, Michel and Ramel, Romain and Grasseau, Gilles and Léger, Laurent and Girou, Denis},
	month = aug,
	year = {2006},
	keywords = {Burkina Faso, AMMA-CATCH, Niger},
	pages = {199--214},
}

@article{rogel_tropical_2006,
	title = {Tropical {Atlantic} moisture availability and precipitation over {West} {Africa}: {Application} to {DEMETER} hindcasts},
	volume = {33},
	issn = {0094-8276},
	shorttitle = {Tropical {Atlantic} moisture availability and precipitation over {West} {Africa}},
	url = {http://doi.wiley.com/10.1029/2006GL027178},
	doi = {10.1029/2006GL027178},
	language = {en},
	number = {21},
	urldate = {2014-06-13},
	journal = {Geophysical Research Letters},
	author = {Rogel, Philippe and Tourre, Yves M. and Benoit, Vincent and Jarlan, Lionel},
	month = nov,
	year = {2006},
	keywords = {AMMA-CATCH, AO},
}

@article{schlecht_spatio-temporal_2006,
	title = {A spatio-temporal analysis of forage availability and grazing and excretion behaviour of herded and free grazing cattle, sheep and goats in {Western} {Niger}},
	volume = {113},
	issn = {01678809},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0167880905004469},
	doi = {10.1016/j.agee.2005.09.008},
	language = {en},
	number = {1-4},
	urldate = {2014-06-13},
	journal = {Agriculture, Ecosystems \& Environment},
	author = {Schlecht, Eva and Hiernaux, Pierre and Kadaouré, Ibrahima and Hülsebusch, Christian and Mahler, Friedrich},
	month = apr,
	year = {2006},
	keywords = {AMMA-CATCH, Niger},
	pages = {226--242},
}

@article{tracol_testing_2006,
	title = {Testing a sahelian grassland functioning model against herbage mass measurements},
	volume = {193},
	issn = {03043800},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0304380005004023},
	doi = {10.1016/j.ecolmodel.2005.08.033},
	language = {en},
	number = {3-4},
	urldate = {2014-06-13},
	journal = {Ecological Modelling},
	author = {Tracol, Y. and Mougin, E. and Hiernaux, P. and Jarlan, L.},
	month = mar,
	year = {2006},
	keywords = {AMMA-CATCH, Mali},
	pages = {437--446},
}

@article{varado_assessment_2006,
	title = {Assessment of an efficient numerical solution of the {1D} {Richards}' equation on bare soil},
	volume = {323},
	issn = {00221694},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0022169405004385},
	doi = {10.1016/j.jhydrol.2005.07.052},
	language = {en},
	number = {1-4},
	urldate = {2014-06-13},
	journal = {Journal of Hydrology},
	author = {Varado, N. and Braud, I. and Ross, P.J. and Haverkamp, R.},
	month = may,
	year = {2006},
	keywords = {AMMA-CATCH, Benin},
	pages = {244--257},
}

@article{ali_rainfall_2005,
	title = {Rainfall {Estimation} in the {Sahel}. {Part} {I}: {Error} {Function}},
	volume = {44},
	issn = {0894-8763, 1520-0450},
	shorttitle = {Rainfall {Estimation} in the {Sahel}. {Part} {I}},
	url = {http://journals.ametsoc.org/doi/abs/10.1175/JAM2304.1},
	doi = {10.1175/JAM2304.1},
	language = {en},
	number = {11},
	urldate = {2014-06-13},
	journal = {Journal of Applied Meteorology},
	author = {Ali, Abdou and Lebel, Thierry and Amani, Abou},
	month = nov,
	year = {2005},
	keywords = {AMMA-CATCH},
	pages = {1691--1706},
}

@article{ali_rainfall_2005-1,
	title = {Rainfall {Estimation} in the {Sahel}. {Part} {II}: {Evaluation} of {Rain} {Gauge} {Networks} in the {CILSS} {Countries} and {Objective} {Intercomparison} of {Rainfall} {Products}},
	volume = {44},
	issn = {0894-8763, 1520-0450},
	shorttitle = {Rainfall {Estimation} in the {Sahel}. {Part} {II}},
	url = {http://journals.ametsoc.org/doi/abs/10.1175/JAM2305.1},
	doi = {10.1175/JAM2305.1},
	language = {en},
	number = {11},
	urldate = {2014-06-13},
	journal = {Journal of Applied Meteorology},
	author = {Ali, Abdou and Amani, Abou and Diedhiou, Arona and Lebel, Thierry},
	month = nov,
	year = {2005},
	keywords = {AMMA-CATCH},
	pages = {1707--1722},
}

@article{philippon_analysis_2005,
	title = {Analysis of the linkages between rainfall and land surface conditions in the {West} {African} monsoon through {CMAP}, {ERS}-{WSC}, and {NOAA}-{AVHRR} data},
	volume = {110},
	issn = {0148-0227},
	url = {http://doi.wiley.com/10.1029/2005JD006394},
	doi = {10.1029/2005JD006394},
	language = {en},
	number = {D24},
	urldate = {2014-06-13},
	journal = {Journal of Geophysical Research},
	author = {Philippon, Nathalie and Mougin, Eric and Jarlan, Lionel and Frison, Pierre-Louis},
	year = {2005},
	keywords = {AMMA-CATCH},
}

@article{seghieri_adaptative_2005,
	title = {Adaptative above-ground biomass, stand density and leaf water potential to droughts and clearing in {Guiera} senegalensis, a dominant shrub in {Sahelian} fallows ({Niger})},
	volume = {21},
	issn = {0266-4674, 1469-7831},
	url = {http://www.journals.cambridge.org/abstract_S0266467404002135},
	doi = {10.1017/S0266467404002135},
	language = {en},
	number = {2},
	urldate = {2014-06-13},
	journal = {Journal of Tropical Ecology},
	author = {Seghieri, Josiane and Simier, Monique and Mahamane, Ali and Hiernaux, Pierre and Rambal, Serge},
	month = mar,
	year = {2005},
	keywords = {AMMA-CATCH},
	pages = {203--213},
}

@article{ago_carbon_2015,
	title = {Carbon dioxide fluxes from a degraded woodland in {West} {Africa} and their responses to main environmental factors},
	volume = {10},
	issn = {1750-0680},
	url = {http://www.cbmjournal.com/content/10/1/22},
	doi = {10.1186/s13021-015-0033-6},
	language = {en},
	number = {1},
	urldate = {2015-09-17},
	journal = {Carbon Balance and Management},
	author = {Ago, Expedit Evariste and Serça, Dominique and Agbossou, Euloge Kossi and Galle, Sylvie and Aubinet, Marc},
	month = dec,
	year = {2015},
	keywords = {AMMA-CATCH, Benin, HYBIS, PHYREV, Nangatchori},
}

@article{turner_distribution_2005,
	title = {The {Distribution} of {Grazing} {Pressure} in {Relation} to {Vegetation} {Resources} in {Semi}-arid {West} {Africa}: {The} {Role} of {Herding}},
	volume = {8},
	issn = {1432-9840, 1435-0629},
	shorttitle = {The {Distribution} of {Grazing} {Pressure} in {Relation} to {Vegetation} {Resources} in {Semi}-arid {West} {Africa}},
	url = {http://link.springer.com/10.1007/s10021-003-0099-y},
	doi = {10.1007/s10021-003-0099-y},
	language = {en},
	number = {6},
	urldate = {2014-06-13},
	journal = {Ecosystems},
	author = {Turner, Matthew D. and Hiernaux, Pierre and Schlecht, Eva},
	month = sep,
	year = {2005},
	keywords = {AMMA-CATCH},
	pages = {668--681},
}

@article{zine_land_2005,
	title = {Land surface parameter monitoring with {ERS} scatterometer data over the {Sahel}: {A} comparison between agro-pastoral and pastoral areas},
	volume = {96},
	issn = {00344257},
	shorttitle = {Land surface parameter monitoring with {ERS} scatterometer data over the {Sahel}},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425705001124},
	doi = {10.1016/j.rse.2005.04.012},
	language = {en},
	number = {3-4},
	urldate = {2014-06-13},
	journal = {Remote Sensing of Environment},
	author = {Zine, S and Jarlan, L and Frison, P and Mougin, E and Hiernaux, P and Rudant, J},
	month = jun,
	year = {2005},
	keywords = {AMMA-CATCH},
	pages = {438--452},
}

@article{gosset_effect_2004,
	title = {Effect of {Nonuniform} {Beam} {Filling} on the {Propagation} of {Radar} {Signals} at {X}-{Band} {Frequencies}. {Part} {II}: {Examination} of {Differential} {Phase} {Shift}},
	volume = {21},
	issn = {0739-0572, 1520-0426},
	shorttitle = {Effect of {Nonuniform} {Beam} {Filling} on the {Propagation} of {Radar} {Signals} at {X}-{Band} {Frequencies}. {Part} {II}},
	url = {http://journals.ametsoc.org/doi/abs/10.1175/1520-0426%282004%29021%3C0358%3AEONBFO%3E2.0.CO%3B2},
	doi = {10.1175/1520-0426(2004)021<0358:EONBFO>2.0.CO;2},
	language = {en},
	number = {2},
	urldate = {2014-06-13},
	journal = {Journal of Atmospheric and Oceanic Technology},
	author = {Gosset, Marielle},
	month = feb,
	year = {2004},
	keywords = {AMMA-CATCH},
	pages = {358--367},
}

@article{herault_soil_2004,
	title = {Soil seed bank and vegetation dynamics in {Sahelian} fallows; the impact of past cropping and current grazing treatments},
	volume = {20},
	issn = {0266-4674, 1469-7831},
	url = {http://www.journals.cambridge.org/abstract_S0266467404001786},
	doi = {10.1017/S0266467404001786},
	language = {en},
	number = {6},
	urldate = {2014-06-13},
	journal = {Journal of Tropical Ecology},
	author = {Hérault, Bruno and Hiernaux, Pierre},
	month = nov,
	year = {2004},
	keywords = {AMMA-CATCH},
	pages = {683--691},
}

@article{jarlan_using_2005,
	title = {Using coarse remote sensing radar observations to control the trajectory of a simple {Sahelian} land surface model},
	volume = {94},
	issn = {00344257},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425704003256},
	doi = {10.1016/j.rse.2004.10.005},
	language = {en},
	number = {2},
	urldate = {2014-06-13},
	journal = {Remote Sensing of Environment},
	author = {Jarlan, L. and Mougin, E. and Mazzega, P. and Schoenauer, M. and Tracol, Y. and Hiernaux, P.},
	month = jan,
	year = {2005},
	keywords = {AMMA-CATCH},
	pages = {269--285},
}

@article{messager_precipitation_2004,
	title = {Precipitation sensitivity to regional {SST} in a regional climate simulation during the {West} {African} monsoon for two dry years},
	volume = {22},
	issn = {0930-7575, 1432-0894},
	url = {http://link.springer.com/10.1007/s00382-003-0381-x},
	doi = {10.1007/s00382-003-0381-x},
	number = {2-3},
	urldate = {2014-06-13},
	journal = {Climate Dynamics},
	author = {Messager, C. and Gallée, H. and Brasseur, O.},
	month = mar,
	year = {2004},
	keywords = {AMMA-CATCH},
	pages = {249--266},
}

@article{onibon_gibbs_2004,
	title = {Gibbs sampling for conditional spatial disaggregation of rain fields: {GIBBS} {SAMPLING} {FOR} {DISAGGREGATION} {OF} {RAIN} {FIELDS}},
	volume = {40},
	issn = {00431397},
	shorttitle = {Gibbs sampling for conditional spatial disaggregation of rain fields},
	url = {http://doi.wiley.com/10.1029/2003WR002009},
	doi = {10.1029/2003WR002009},
	language = {en},
	number = {8},
	urldate = {2014-06-13},
	journal = {Water Resources Research},
	author = {Onibon, Hubert and Lebel, Thierry and Afouda, Abel and Guillot, Gilles},
	month = aug,
	year = {2004},
	keywords = {AMMA-CATCH},
	pages = {n/a--n/a},
}

@article{powell_croplivestock_2004,
	title = {Crop–{Livestock} {Interactions} in the {West} {African} {Drylands}},
	volume = {96},
	issn = {1435-0645},
	url = {https://www.agronomy.org/publications/aj/abstracts/96/2/469},
	doi = {10.2134/agronj2004.0469},
	language = {en},
	number = {2},
	urldate = {2014-06-13},
	journal = {Agronomy Journal},
	author = {Powell, J. Mark and Pearson, R. Anne and Hiernaux, Pierre H.},
	year = {2004},
	keywords = {AMMA-CATCH},
	pages = {469},
}

@article{seghieri_characterization_2004,
	title = {Characterization of the variability of the daily course of leaf water potential in the dominant shrub species within {Sahelian} fallows in south-west {Niger}},
	volume = {173},
	issn = {03043800},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0304380003004113},
	doi = {10.1016/j.ecolmodel.2003.10.001},
	language = {en},
	number = {2-3},
	urldate = {2014-06-13},
	journal = {Ecological Modelling},
	author = {Seghieri, Josiane and Laloë, Francis},
	month = apr,
	year = {2004},
	keywords = {AMMA-CATCH},
	pages = {271--281},
}

@article{ali_invariance_2003,
	title = {Invariance in the {Spatial} {Structure} of {Sahelian} {Rain} {Fields} at {Climatological} {Scales}},
	volume = {4},
	issn = {1525-755X, 1525-7541},
	url = {http://journals.ametsoc.org/doi/abs/10.1175/1525-7541%282003%29004%3C0996%3AIITSSO%3E2.0.CO%3B2},
	doi = {10.1175/1525-7541(2003)004<0996:IITSSO>2.0.CO;2},
	language = {en},
	number = {6},
	urldate = {2014-06-13},
	journal = {Journal of Hydrometeorology},
	author = {Ali, Abdou and Lebel, Thierry and Amani, Abou},
	month = dec,
	year = {2003},
	keywords = {AMMA-CATCH},
	pages = {996--1011},
}

@article{bouvier_generating_2003,
	title = {Generating rainfall fields using principal components ({PC}) decomposition of the covariance matrix: a case study in {Mexico} {City}},
	volume = {278},
	issn = {00221694},
	shorttitle = {Generating rainfall fields using principal components ({PC}) decomposition of the covariance matrix},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0022169403001227},
	doi = {10.1016/S0022-1694(03)00122-7},
	language = {en},
	number = {1-4},
	urldate = {2014-06-13},
	journal = {Journal of Hydrology},
	author = {Bouvier, Christophe and Cisneros, Leonardo and Dominguez, Ramon and Laborde, Jean-Pierre and Lebel, Thierry},
	month = jul,
	year = {2003},
	keywords = {AMMA-CATCH},
	pages = {107--120},
}

@article{durieux_impact_2003,
	title = {The impact of deforestation on cloud cover over the {Amazon} arc of deforestation},
	volume = {86},
	issn = {00344257},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425703000956},
	doi = {10.1016/S0034-4257(03)00095-6},
	language = {en},
	number = {1},
	urldate = {2014-06-13},
	journal = {Remote Sensing of Environment},
	author = {Durieux, L and Machado, Luiz A. T. and Laurent, H},
	month = jun,
	year = {2003},
	keywords = {AMMA-CATCH},
	pages = {132--140},
}

@article{gandah_strategies_2003,
	title = {Strategies to optimize allocation of limited nutrients to sandy soils of the {Sahel}: a case study from {Niger}, west {Africa}},
	volume = {94},
	issn = {01678809},
	shorttitle = {Strategies to optimize allocation of limited nutrients to sandy soils of the {Sahel}},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S016788090200035X},
	doi = {10.1016/S0167-8809(02)00035-X},
	language = {en},
	number = {3},
	urldate = {2014-06-13},
	journal = {Agriculture, Ecosystems \& Environment},
	author = {Gandah, M. and Bouma, J. and Brouwer, J. and Hiernaux, P. and Van Duivenbooden, N.},
	month = mar,
	year = {2003},
	keywords = {AMMA-CATCH},
	pages = {311--319},
}

@article{jarlan_mapping_2003,
	title = {Mapping of {Sahelian} vegetation parameters from {ERS} scatterometer data with an evolution strategies algorithm},
	volume = {87},
	issn = {00344257},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425703001640},
	doi = {10.1016/S0034-4257(03)00164-0},
	language = {en},
	number = {1},
	urldate = {2014-06-13},
	journal = {Remote Sensing of Environment},
	author = {Jarlan, L and Mazzega, P and Mougin, E and Lavenu, F and Marty, G and Frison, P.L and Hiernaux, P},
	month = sep,
	year = {2003},
	keywords = {AMMA-CATCH},
	pages = {72--84},
}

@article{lebel_seasonal_2003,
	title = {Seasonal cycle and interannual variability of the {Sahelian} rainfall at hydrological scales},
	volume = {108},
	issn = {0148-0227},
	url = {http://doi.wiley.com/10.1029/2001JD001580},
	doi = {10.1029/2001JD001580},
	language = {en},
	number = {D8},
	urldate = {2014-06-13},
	journal = {Journal of Geophysical Research},
	author = {Lebel, Thierry and Diedhiou, A. and Laurent, H},
	year = {2003},
	keywords = {AMMA-CATCH},
}

@article{hector_water_2015,
	title = {Water storage changes as a marker for base flow generation processes in a tropical humid basement catchment ({Benin}): {Insights} from hybrid gravimetry: hybrid gravimetry for base flow processes in {West} {Africa}},
	volume = {51},
	issn = {0043-1397},
	shorttitle = {Water storage changes as a marker for base flow generation processes in a tropical humid basement catchment ({Benin})},
	url = {http://doi.wiley.com/10.1002/2014WR015773},
	doi = {10.1002/2014wr015773},
	abstract = {In basement catchments of subhumid West Africa, base flow is the main component of annual streamflow. However, the important heterogeneity of lithology hinders the understanding of base flow generation processes. Since these processes are linked with water storage changes (WSCs) across the catchment, we propose the use of hybrid gravity data in addition to neutron probe-derived water content and water levels to monitor spatiotemporal WSC of a typical crystalline basement headwater catchment (16 ha) in Benin. WSC behaviors are shown to provide insights into hydrological processes in terms of water redistribution toward the catchment outlet. Hybrid gravimetry produces gravity change observations from time-lapse microgravity surveys coupled with gravity changes monitored at a base station using a superconducting gravimeter and/or an absolute gravimeter. A dense microgravity campaign (70 surveys of 14 stations) covering three contrasted years was set up with a rigorous protocol, leading to low uncertainties ({\textless} 2.5 mu Gal) on station gravity determinations (with respect to the network reference station). Empirical orthogonal function analyses of both gravity changes and WSCs from neutron probe data show similar spatial patterns in the seasonal signal. Areas where storage and water table show a capping behavior (when data reach a plateau during the wet season), suggesting threshold-governed fast subsurface redistribution, are identified. This observed storage dynamics, together with geological structures investigated by electrical resistivity tomography and drill log analysis, make it possible to derive a conceptual model for the catchment hydrology.},
	language = {en},
	number = {10},
	urldate = {2015-11-12},
	journal = {Water Resources Research},
	author = {Hector, Basile and Séguis, Luc and Hinderer, Jacques and Cohard, Jean-Martial and Wubda, Maxime and Descloitres, Marc and Benarrosh, Nathalie and Boy, Jean-Paul},
	month = oct,
	year = {2015},
	keywords = {AMMA-CATCH, Benin, extérieur, PHYREV},
	pages = {8331--8361},
}

@article{elbaz-poulichet_major_2002,
	title = {Major ion chemistry of groundwaters in the {Continental} {Terminal} water table of southwestern {Niger} ({Africa})},
	volume = {17},
	issn = {08832927},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0883292702000240},
	doi = {10.1016/S0883-2927(02)00024-0},
	language = {en},
	number = {10},
	urldate = {2014-06-13},
	journal = {Applied Geochemistry},
	author = {Elbaz-Poulichet, Françoise and Favreau, Guillaume and Leduc, Christian and Seidel, Jean Luc},
	month = oct,
	year = {2002},
	keywords = {AMMA-CATCH},
	pages = {1343--1349},
}

@article{elizondo_automatic_2002,
	title = {Automatic versus manual model differentiation to compute sensitivities and solve non-linear inverse problems},
	volume = {28},
	issn = {00983004},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0098300401000486},
	doi = {10.1016/S0098-3004(01)00048-6},
	language = {en},
	number = {3},
	urldate = {2014-06-13},
	journal = {Computers \& Geosciences},
	author = {Elizondo, D. and Cappelaere, B. and Faure, Ch.},
	month = apr,
	year = {2002},
	keywords = {AMMA-CATCH},
	pages = {309--326},
}

@article{leduc_long-term_2001,
	title = {Long-term rise in a {Sahelian} water-table: the {Continental} {Terminal} in {South}-{West} {Niger}},
	volume = {243},
	issn = {00221694},
	shorttitle = {Long-term rise in a {Sahelian} water-table},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0022169400004030},
	doi = {10.1016/S0022-1694(00)00403-0},
	language = {en},
	number = {1-2},
	urldate = {2014-06-13},
	journal = {Journal of Hydrology},
	author = {Leduc, C and Favreau, G and Schroeter, P},
	month = mar,
	year = {2001},
	keywords = {AMMA-CATCH},
	pages = {43--54},
}

@article{favreau_reply_2002,
	title = {Reply to comment on ‘{Long}-term rise in a {Sahelian} water-table: the {Continental} {Terminal} in {South}-{West} {Niger}’ by {Leduc}, {C}., {Favreau}, {G}., {Schroeter}, {P}., 2001. {Journal} of {Hydrology} 243, 43–54},
	volume = {255},
	issn = {00221694},
	shorttitle = {Reply to comment on ‘{Long}-term rise in a {Sahelian} water-table},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0022169401005170},
	doi = {10.1016/S0022-1694(01)00517-0},
	language = {en},
	number = {1-4},
	urldate = {2014-06-13},
	journal = {Journal of Hydrology},
	author = {Favreau, G. and Leduc, C. and Schroeter, P.},
	month = jan,
	year = {2002},
	keywords = {AMMA-CATCH},
	pages = {263--265},
}

@article{jarlan_analysis_2002,
	title = {Analysis of {ERS} wind scatterometer time series over {Sahel} ({Mali})},
	volume = {81},
	issn = {00344257},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425702000159},
	doi = {10.1016/S0034-4257(02)00015-9},
	language = {en},
	number = {2-3},
	urldate = {2014-06-13},
	journal = {Remote Sensing of Environment},
	author = {Jarlan, L and Mougin, E and Frison, P.L and Mazzega, P and Hiernaux, P},
	month = aug,
	year = {2002},
	keywords = {AMMA-CATCH, Mali},
	pages = {404--415},
}

@article{jarlan_retrieval_2002,
	title = {Retrieval of land surface parameters in the {Sahel} from {ERS} wind scatterometer data: a "brute force" method},
	volume = {40},
	issn = {0196-2892},
	shorttitle = {Retrieval of land surface parameters in the {Sahel} from {ERS} wind scatterometer data},
	doi = {10.1109/TGRS.2002.802500},
	abstract = {The retrieval of surface parameters, namely, the soil moisture content and the herbaceous above-ground biomass, from European Remote Sensing (ERS) wind-scatterometer data is investigated for a Sahelian study site during the period 1993-1994. Thanks to the low dimension of the unknown parameter vector, a systematic exploration of the parameter space could be carried out. This method allows the recovery of the optimal parameter set as well as an exhaustive description of the subdomain of acceptable solutions. The mapping of this subdomain points out the lack of constraints brought by the ERS dataset on the determination of the surface parameters. Particularly, additional constraints should be found on the rapid and short-scale variation of the soil moisture content. Moreover, it is shown that the distributions of the retrieved parameters are not normal nor log normal, as could be expected from random variables. As a consequence, the optimal parameter set is neither the average nor the maximum likelihood, and the computation of an a posteriori standard deviation of the parameters is meaningless.},
	number = {9},
	journal = {IEEE Transactions on Geoscience and Remote Sensing},
	author = {Jarlan, L. and Mazzega, P. and Mougin, E.},
	month = sep,
	year = {2002},
	keywords = {remote sensing, Sahel, Soil moisture, land surface, vegetation mapping, Inverse problems, AMMA-CATCH, Spaceborne radar, moisture, remote sensing by radar, soil, Cost function, ERS wind scatterometer data, herbaceous above-ground biomass, hydrological techniques, Information retrieval, land surface parameters, Least squares methods, nonlinear optimization, optimal parameter set, Radar measurements, soil moisture content, subdomain, Uninterruptible power systems, unknown parameter vector},
	pages = {2056--2062},
}

@article{jenkins_investigating_2002,
	title = {Investigating the {West} {African} {Climate} {System} {Using} {Global}/{Regional} {Climate} {Models}},
	volume = {83},
	issn = {0003-0007, 1520-0477},
	url = {http://journals.ametsoc.org/doi/abs/10.1175/1520-0477%282002%29083%3C0583%3AITWACS%3E2.3.CO%3B2},
	doi = {10.1175/1520-0477(2002)083<0583:ITWACS>2.3.CO;2},
	language = {en},
	number = {4},
	urldate = {2014-06-13},
	journal = {Bulletin of the American Meteorological Society},
	author = {Jenkins, Gregory S. and Kamga, Andre and Garba, Adamou and Diedhiou, Arona and Morris, Vernon and Joseph, Everette},
	month = apr,
	year = {2002},
	keywords = {AMMA-CATCH},
	pages = {583--595},
}

@article{lebel_gcm_2000,
	title = {From {GCM} scales to hydrological scales: rainfall variability in {West} {Africa}},
	volume = {14},
	issn = {14363240},
	shorttitle = {From {GCM} scales to hydrological scales},
	url = {http://link.springer.com/10.1007/s004770000050},
	doi = {10.1007/s004770000050},
	number = {4},
	urldate = {2014-06-13},
	journal = {Stochastic Environmental Research and Risk Assessment},
	author = {Lebel, T. and Delclaux, F. and Le Barbé, L. and Polcher, J.},
	month = sep,
	year = {2000},
	keywords = {AMMA-CATCH},
	pages = {0275--0295},
}

@article{mathon_mesoscale_2002,
	title = {Mesoscale {Convective} {System} {Rainfall} in the {Sahel}},
	volume = {41},
	issn = {0894-8763, 1520-0450},
	url = {http://journals.ametsoc.org/doi/abs/10.1175/1520-0450%282002%29041%3C1081%3AMCSRIT%3E2.0.CO%3B2},
	doi = {10.1175/1520-0450(2002)041<1081:MCSRIT>2.0.CO;2},
	language = {en},
	number = {11},
	urldate = {2014-06-13},
	journal = {Journal of Applied Meteorology},
	author = {Mathon, Vincent and Laurent, Henri and Lebel, Thierry},
	month = nov,
	year = {2002},
	keywords = {AMMA-CATCH},
	pages = {1081--1092},
}

@article{mathon_relationship_2002,
	title = {Relationship between easterly waves and mesoscale convective systems over the {Sahel}},
	volume = {29},
	issn = {0094-8276},
	url = {http://doi.wiley.com/10.1029/2001GL014371},
	doi = {10.1029/2001GL014371},
	language = {en},
	number = {8},
	urldate = {2014-06-13},
	journal = {Geophysical Research Letters},
	author = {Mathon, Vincent},
	year = {2002},
	keywords = {AMMA-CATCH},
}

@article{redelsperger_multi-scale_2002,
	title = {Multi-scale description of a {Sahelian} synoptic weather system representative of the {West} {African} monsoon},
	volume = {128},
	issn = {00000000, 00359009},
	url = {http://doi.wiley.com/10.1256/003590002320373274},
	doi = {10.1256/003590002320373274},
	number = {582},
	urldate = {2014-06-13},
	journal = {Quarterly Journal of the Royal Meteorological Society},
	author = {Redelsperger, J.-L. and Diongue, A. and Diedhiou, A. and Ceron, J.-P. and Diop, M. and Gueremy, J.-F. and Lafore, J.-P.},
	month = apr,
	year = {2002},
	keywords = {AMMA-CATCH},
	pages = {1229--1257},
}

@article{seghieri_variations_2002,
	title = {Variations in phenology of a residual invasive shrub species in {Sahelian} fallow savannas, south-west {Niger}},
	volume = {18},
	issn = {0266-4674, 1469-7831},
	url = {http://www.journals.cambridge.org/abstract_S0266467402002584},
	doi = {10.1017/S0266467402002584},
	language = {en},
	number = {06},
	urldate = {2014-06-13},
	journal = {Journal of Tropical Ecology},
	author = {Seghieri, Josiane and Simier, Monique},
	month = nov,
	year = {2002},
	keywords = {AMMA-CATCH},
}

@article{seguis_impact_2002,
	title = {Impact on {Sahelian} runoff of stochastic and elevation-induced spatial distributions of soil parameters},
	volume = {16},
	issn = {0885-6087, 1099-1085},
	url = {http://doi.wiley.com/10.1002/hyp.337},
	doi = {10.1002/hyp.337},
	language = {en},
	number = {2},
	urldate = {2014-06-13},
	journal = {Hydrological Processes},
	author = {Séguis, Luc and Cappelaere, Bernard and Peugeot, Christophe and Vieux, Baxter},
	month = feb,
	year = {2002},
	keywords = {AMMA-CATCH},
	pages = {313--332},
}

@article{bonazzola_retrieval_2001,
	title = {Retrieval of large-scale wind divergences from infrared {Meteosat}-5 brightness temperatures over the {Indian} {Ocean}},
	volume = {106},
	issn = {01480227},
	url = {http://doi.wiley.com/10.1029/2000JD900690},
	doi = {10.1029/2000JD900690},
	language = {en},
	number = {D22},
	urldate = {2014-06-13},
	journal = {Journal of Geophysical Research: Atmospheres},
	author = {Bonazzola, M. and Picon, L. and Laurent, H. and Hourdin, F. and Sèze, G. and Pawlowska, H. and Sadourny, R.},
	month = nov,
	year = {2001},
	keywords = {AMMA-CATCH},
	pages = {28113--28128},
}

@article{mathon_life_2001,
	title = {Life cycle of {Sahelian} mesoscale convective cloud systems},
	volume = {127},
	issn = {00359009, 1477870X},
	url = {http://doi.wiley.com/10.1002/qj.49712757208},
	doi = {10.1002/qj.49712757208},
	language = {en},
	number = {572},
	urldate = {2014-06-13},
	journal = {Quarterly Journal of the Royal Meteorological Society},
	author = {Mathon, Vincent and Laurent, Henri},
	month = jan,
	year = {2001},
	keywords = {AMMA-CATCH},
	pages = {377--406},
}

@article{pierre_modeling_2015,
	title = {Modeling vegetation and wind erosion from a millet field and from a rangeland: {Two} {Sahelian} case studies},
	volume = {19},
	issn = {18759637},
	shorttitle = {Modeling vegetation and wind erosion from a millet field and from a rangeland},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S1875963715000907},
	doi = {10.1016/j.aeolia.2015.09.009},
	language = {en},
	urldate = {2015-11-23},
	journal = {Aeolian Research},
	author = {Pierre, Caroline and Kergoat, Laurent and Bergametti, Gilles and Mougin, Éric and Baron, Christian and Abdourhamane Toure, Amadou and Rajot, Jean-Louis and Hiernaux, Pierre and Marticorena, Béatrice and Delon, Claire},
	month = dec,
	year = {2015},
	keywords = {AMMA-CATCH, Niger, Mali, AO},
	pages = {97--111},
}

@article{favreau_representativite_2000,
	title = {Représentativité de l'échantillonnage géochimique et hydrodynamique en nappe libre du milieu semi-aride ({Reliability} of geochemical and hydrodynamic sample in a semi-arid water table)},
	volume = {31},
	issn = {1464343X},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0899536200800147},
	doi = {10.1016/S0899-5362(00)80014-7},
	language = {fr},
	number = {3-4},
	urldate = {2014-06-13},
	journal = {Journal of African Earth Sciences},
	author = {Favreau, G. and Leduc, C. and Marlin, C.},
	month = oct,
	year = {2000},
	keywords = {AMMA-CATCH},
	pages = {669--678},
}

@article{couteron_test_2003,
	title = {A test for spatial relationships between neighbouring plants in plots of heterogeneous plant density},
	volume = {14},
	issn = {11009233},
	url = {http://doi.wiley.com/10.1111/j.1654-1103.2003.tb02141.x},
	doi = {10.1111/j.1654-1103.2003.tb02141.x},
	language = {en},
	number = {2},
	urldate = {2014-06-16},
	journal = {Journal of Vegetation Science},
	author = {Couteron, Pierre and Seghieri, Josiane and Chadœuf, Joël},
	month = apr,
	year = {2003},
	keywords = {AMMA-CATCH},
	pages = {163--172},
}

@article{diedhiou_energetics_2002,
	title = {Energetics of easterly wave disturbances over {West} {Africa} and the tropical {Atlantic}: a climatology from the 1979-95 {NCEP}/{NCAR} reanalyses},
	volume = {18},
	issn = {0930-7575, 1432-0894},
	shorttitle = {Energetics of easterly wave disturbances over {West} {Africa} and the tropical {Atlantic}},
	url = {http://link.springer.com/10.1007/s00382-001-0195-7},
	doi = {10.1007/s00382-001-0195-7},
	number = {6},
	urldate = {2014-06-16},
	journal = {Climate Dynamics},
	author = {Diedhiou, A. and Janicot, S and Viltard, N. and de Félice, P.},
	month = feb,
	year = {2002},
	keywords = {AMMA-CATCH},
	pages = {487--500},
}

@article{dardel_rain-use-efficiency_2014,
	title = {Rain-{Use}-{Efficiency}: {What} it {Tells} us about the {Conflicting} {Sahel} {Greening} and {Sahelian} {Paradox}},
	volume = {6},
	issn = {2072-4292},
	shorttitle = {Rain-{Use}-{Efficiency}},
	url = {http://www.mdpi.com/2072-4292/6/4/3446/},
	doi = {10.3390/rs6043446},
	language = {en},
	number = {4},
	urldate = {2014-06-26},
	journal = {Remote Sensing},
	author = {Dardel, Cécile and Kergoat, Laurent and Hiernaux, Pierre and Grippa, Manuela and Mougin, Eric and Ciais, Philippe and Nguyen, Cam-Chi},
	month = apr,
	year = {2014},
	keywords = {AMMA-CATCH},
	pages = {3446--3474},
}

@article{ago_mesure_2016,
	title = {Mesure des flux de {CO2} et séquestration de carbone dans les écosystèmes terrestres ouest-africains (synthèse bibliographique)},
	volume = {20},
	url = {http://popups.ulg.ac.be/1780-4507/index.php?id=12565},
	doi = {pas de doi},
	language = {fr},
	number = {1},
	journal = {Biotechnologie, Agronomie, Société et Environnement},
	author = {Ago, Expedit Evariste and Agbossou, Euloge Kossi and Ozer, Pierre and Aubinet, Marc},
	year = {2016},
	keywords = {AMMA-CATCH, extérieur, benin, biblio},
	pages = {2--15},
}

@article{ringard_intensification_2016,
	title = {The intensification of thermal extremes in west {Africa}},
	volume = {139},
	issn = {09218181},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0921818115301624},
	doi = {10.1016/j.gloplacha.2015.12.009},
	language = {en},
	urldate = {2016-01-27},
	journal = {Global and Planetary Change},
	author = {Ringard, J. and Dieppois, B. and Rome, S. and Diedhiou, A. and Pellarin, T. and Konaré, A. and Diawara, A. and Konaté, D. and Dje, B.K. and Katiellou, G.L. and Seidou Sanda, I. and Hassane, B. and Vischel, T. and Garuma, G.F. and Mengistu, G. and Camara, M. and Diongue, A. and Gaye, A.T. and Descroix, L.},
	month = apr,
	year = {2016},
	keywords = {AMMA-CATCH, AO, PHYREV},
	pages = {66--77},
}

@article{panthou_caracterisation_2015,
	title = {Caractérisation de la structure spatio - temporelle des pluies extrêmes : estimation de courbes {IDSF} pour la région de {Niamey}},
	issn = {0018-6368, 1958-5551},
	shorttitle = {Caractérisation de la structure spatio - temporelle des pluies extrêmes},
	url = {http://www.shf-lhb.org/10.1051/lhb/20150034},
	doi = {10.1051/lhb/20150034},
	language = {Français},
	number = {3},
	urldate = {2016-03-08},
	journal = {La Houille Blanche},
	author = {Panthou, Gérémy and Vischel, Théo and Lebel, Thierry and Quantin, Guillaume and Ali, Abdou},
	month = jun,
	year = {2015},
	keywords = {Sahel, AMMA-CATCH, AO, phyrev},
	pages = {58--63},
}

@article{pfeifroth_evaluating_2016,
	title = {Evaluating {Satellite}-{Based} {Diurnal} {Cycles} of {Precipitation} in the {African} {Tropics}},
	volume = {55},
	issn = {1558-8424, 1558-8432},
	url = {http://journals.ametsoc.org/doi/abs/10.1175/JAMC-D-15-0065.1},
	doi = {10.1175/JAMC-D-15-0065.1},
	language = {en},
	number = {1},
	urldate = {2016-03-08},
	journal = {Journal of Applied Meteorology and Climatology},
	author = {Pfeifroth, Uwe and Trentmann, Jörg and Fink, Andreas H. and Ahrens, Bodo},
	month = jan,
	year = {2016},
	keywords = {AMMA-CATCH, ext1, extérieur, AO},
	pages = {23--39},
}

@article{hassane_impacts_2016,
	title = {Impacts of a large {Sahelian} city on groundwater hydrodynamics and quality: example of {Niamey} ({Niger})},
	volume = {24},
	issn = {1431-2174, 1435-0157},
	shorttitle = {Impacts of a large {Sahelian} city on groundwater hydrodynamics and quality},
	url = {http://link.springer.com/10.1007/s10040-015-1345-z},
	doi = {10.1007/s10040-015-1345-z},
	language = {en},
	number = {2},
	urldate = {2016-03-09},
	journal = {Hydrogeology Journal},
	author = {Hassane, Aïssata B. and Leduc, Christian and Favreau, Guillaume and Bekins, Barbara A. and Margueron, Thomas},
	month = mar,
	year = {2016},
	keywords = {AMMA-CATCH, ext1, Niger},
	pages = {407--423},
}

@article{awessou_differences_2016,
	title = {Differences in transpiration between a forest and an agroforestry tree species in the {Sudanian} belt},
	volume = {91},
	issn = {0167-4366, 1572-9680},
	url = {http://link.springer.com/10.1007/s10457-016-9937-8},
	doi = {10.1007/s10457-016-9937-8},
	language = {en},
	number = {3},
	urldate = {2016-04-26},
	journal = {Agroforestry Systems},
	author = {Awessou, Kohomlan G. Beranger and Peugeot, Christophe and Rocheteau, Alain and Séguis, Luc and Do, Frédéric C. and Galle, Sylvie and Bellanger, Marie and Agbossou, Euloge and Seghieri, Josiane},
	year = {2016},
	keywords = {AMMA-CATCH, PHYREV, phyrev, Ben},
	pages = {403--413},
}

@article{cairo_introduction_2010,
	title = {An introduction to the {SCOUT}-{AMMA} stratospheric aircraft, balloons and sondes campaign in {West} {Africa}, {August} 2006: rationale and roadmap},
	volume = {10},
	issn = {1680-7324},
	shorttitle = {An introduction to the {SCOUT}-{AMMA} stratospheric aircraft, balloons and sondes campaign in {West} {Africa}, {August} 2006},
	url = {http://www.atmos-chem-phys.net/10/2237/2010/},
	doi = {10.5194/acp-10-2237-2010},
	language = {en},
	number = {5},
	urldate = {2014-06-13},
	journal = {Atmospheric Chemistry and Physics},
	author = {Cairo, F. and Pommereau, J. P. and Law, K. S. and Schlager, H. and Garnier, A. and Fierli, F. and Ern, M. and Streibel, M. and Arabas, S. and Borrmann, S. and Berthelier, J. J. and Blom, C. and Christensen, T. and D'Amato, F. and Di Donfrancesco, G. and Deshler, T. and Diedhiou, A. and Durry, G. and Engelsen, O. and Goutail, F. and Harris, N. R. P. and Kerstel, E. R. T. and Khaykin, S. and Konopka, P. and Kylling, A. and Larsen, N. and Lebel, T. and Liu, X. and MacKenzie, A. R. and Nielsen, J. and Oulanowski, A. and Parker, D. J. and Pelon, J. and Polcher, J. and Pyle, J. A. and Ravegnani, F. and Rivière, E. D. and Robinson, A. D. and Röckmann, T. and Schiller, C. and Simões, F. and Stefanutti, L. and Stroh, F. and Some, L. and Siegmund, P. and Sitnikov, N. and Vernier, J. P. and Volk, C. M. and Voigt, C. and von Hobe, M. and Viciani, S. and Yushkov, V.},
	month = mar,
	year = {2010},
	keywords = {AMMA-CATCH},
	pages = {2237--2256},
}

@article{duku_towards_2015,
	title = {Towards ecosystem accounting: a comprehensive approach to modelling multiple hydrological ecosystem services},
	volume = {19},
	issn = {1607-7938},
	shorttitle = {Towards ecosystem accounting},
	url = {http://www.hydrol-earth-syst-sci.net/19/4377/2015/},
	doi = {10.5194/hess-19-4377-2015},
	language = {en},
	number = {10},
	urldate = {2016-04-06},
	journal = {Hydrology and Earth System Sciences},
	author = {Duku, C. and Rathjens, H. and Zwart, S. J. and Hein, L.},
	month = oct,
	year = {2015},
	keywords = {AMMA-CATCH, ext1, extérieur, ?, Sénégal},
	pages = {4377--4396},
}

@article{panthou_estimation_2015,
	title = {Estimation de cartes d'aléa pluviométrique en {Afrique} de l'{Ouest} : comparaison de différentes approches},
	issn = {0018-6368},
	shorttitle = {Estimation de cartes d'aléa pluviométrique en {Afrique} de l'{Ouest}},
	url = {http://www.shf-lhb.org/10.1051/lhb/20150067},
	doi = {10.1051/lhb/20150067},
	language = {Français},
	number = {6},
	urldate = {2016-06-15},
	journal = {La Houille Blanche},
	author = {Panthou, Gérémy and Vischel, Théo and Lebel, Thierry and Blanchet, Juliette and Quantin, Guillaume and Ali, Abdou},
	month = dec,
	year = {2015},
	keywords = {Sahel, AMMA-CATCH, AO, PHYREV},
	pages = {42--48},
}

@article{tagesson_very_2016,
	title = {Very high {CO2} exchange fluxes at the peak of the rainy season in a {West} {African} grazed semi-arid savanna ecosystem},
	issn = {0016-7223, 1903-2471},
	url = {http://www.tandfonline.com/doi/full/10.1080/00167223.2016.1178072},
	doi = {10.1080/00167223.2016.1178072},
	language = {en},
	urldate = {2016-07-11},
	journal = {Geografisk Tidsskrift-Danish Journal of Geography},
	author = {Tagesson, Torbern and Ardö, Jonas and Guiro, Idrissa and Cropley, Ford and Mbow, Cheikh and Horion, Stephanie and Ehammer, Andrea and Mougin, Eric and Delon, Claire and Galy-Lacaux, Corinne and Fensholt, Rasmus},
	month = jul,
	year = {2016},
	keywords = {AMMA-CATCH, ext1, AO},
	pages = {1--17},
}

@article{brandt_woody_2016,
	title = {Woody plant cover estimation in drylands from {Earth} {Observation} based seasonal metrics},
	volume = {172},
	issn = {00344257},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425715301875},
	doi = {10.1016/j.rse.2015.10.036},
	language = {en},
	urldate = {2016-07-11},
	journal = {Remote Sensing of Environment},
	author = {Brandt, Martin and Hiernaux, Pierre and Tagesson, Torbern and Verger, Aleixandre and Rasmussen, Kjeld and Diouf, Abdoul Aziz and Mbow, Cheikh and Mougin, Eric and Fensholt, Rasmus},
	month = jan,
	year = {2016},
	keywords = {AMMA-CATCH, ext1, AO},
	pages = {28--38},
}

@article{gal_changes_2016,
	title = {Changes in lakes water volume and runoff over ungauged {Sahelian} watersheds},
	volume = {540},
	issn = {00221694},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0022169416304656},
	doi = {10.1016/j.jhydrol.2016.07.035},
	language = {en},
	urldate = {2016-10-10},
	journal = {Journal of Hydrology},
	author = {Gal, L. and Grippa, M. and Hiernaux, P. and Peugeot, C. and Mougin, E. and Kergoat, L.},
	month = sep,
	year = {2016},
	keywords = {Sahel, AMMA-CATCH},
	pages = {1176--1188},
}

@article{pierre_changes_2016,
	title = {Changes in {Sahelian} annual vegetation growth and phenology since 1960: {A} modeling approach},
	volume = {143},
	issn = {09218181},
	shorttitle = {Changes in {Sahelian} annual vegetation growth and phenology since 1960},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0921818115301570},
	doi = {10.1016/j.gloplacha.2016.06.009},
	language = {en},
	urldate = {2016-10-10},
	journal = {Global and Planetary Change},
	author = {Pierre, C. and Grippa, M. and Mougin, E. and Guichard, F. and Kergoat, L.},
	month = aug,
	year = {2016},
	keywords = {Sahel, AMMA-CATCH, AO},
	pages = {162--174},
}

@article{casse_model-based_2016,
	title = {Model-based study of the role of rainfall and land use–land cover in the changes in the occurrence and intensity of {Niger} red floods in {Niamey} between 1953 and 2012},
	volume = {20},
	issn = {1607-7938},
	url = {http://www.hydrol-earth-syst-sci.net/20/2841/2016/},
	doi = {10.5194/hess-20-2841-2016},
	language = {en},
	number = {7},
	urldate = {2016-10-10},
	journal = {Hydrology and Earth System Sciences},
	author = {Casse, Claire and Gosset, Marielle and Vischel, Théo and Quantin, Guillaume and Tanimoun, Bachir Alkali},
	month = jul,
	year = {2016},
	keywords = {AMMA-CATCH, niger, PHYREV, attribution, Niger river},
	pages = {2841--2859},
}

@article{tagesson_spatiotemporal_2016,
	title = {Spatiotemporal variability in carbon exchange fluxes across the {Sahel}},
	volume = {226-227},
	issn = {01681923},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192316302787},
	doi = {10.1016/j.agrformet.2016.05.013},
	language = {en},
	urldate = {2016-10-10},
	journal = {Agricultural and Forest Meteorology},
	author = {Tagesson, Torbern and Fensholt, Rasmus and Cappelaere, Bernard and Mougin, Eric and Horion, Stéphanie and Kergoat, Laurent and Nieto, Héctor and Mbow, Cheikh and Ehammer, Andrea and Demarty, Jérôme and Ardö, Jonas},
	month = oct,
	year = {2016},
	keywords = {AMMA-CATCH, ext1, AO},
	pages = {108--118},
}

@article{kerr_overview_2016,
	title = {Overview of {SMOS} performance in terms of global soil moisture monitoring after six years in operation},
	volume = {180},
	issn = {00344257},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425716300700},
	doi = {10.1016/j.rse.2016.02.042},
	language = {en},
	urldate = {2016-10-10},
	journal = {Remote Sensing of Environment},
	author = {Kerr, Y.H. and Al-Yaari, A. and Rodriguez-Fernandez, N. and Parrens, M. and Molero, B. and Leroux, D. and Bircher, S. and Mahmoodi, A. and Mialon, A. and Richaume, P. and Delwart, S. and Al Bitar, A. and Pellarin, T. and Bindlish, R. and Jackson, T.J. and Rüdiger, C. and Waldteufel, P. and Mecklenburg, S. and Wigneron, J.-P.},
	month = jul,
	year = {2016},
	keywords = {AMMA-CATCH, ext1, AO, PHYREV},
	pages = {40--63},
}

@article{makris_stochastic_2016,
	title = {Stochastic tracking of mesoscale convective systems: evaluation in the {West} {African} {Sahel}},
	volume = {30},
	issn = {1436-3240, 1436-3259},
	shorttitle = {Stochastic tracking of mesoscale convective systems},
	url = {http://link.springer.com/10.1007/s00477-015-1102-9},
	doi = {10.1007/s00477-015-1102-9},
	language = {en},
	number = {2},
	urldate = {2016-10-10},
	journal = {Stochastic Environmental Research and Risk Assessment},
	author = {Makris, Alexandros and Prieur, Clémentine and Vischel, Théo and Quantin, Guillaume and Lebel, Thierry and Roca, Rémy},
	month = feb,
	year = {2016},
	keywords = {AMMA-CATCH, ext1, AO, PHYREV},
	pages = {681--691},
}

@article{cazenave_characterization_2016,
	title = {Characterization of {Hydrometeors} in {Sahelian} {Convective} {Systems} with an {X}-{Band} {Radar} and {Comparison} with {In} {Situ} {Measurements}. {Part} {I}: {Sensitivity} of {Polarimetric} {Radar} {Particle} {Identification} {Retrieval} and {Case} {Study} {Evaluation}},
	volume = {55},
	doi = {10.1175/jamc-d-15-0013.1},
	number = {2},
	journal = {Journal of Applied Meteorology and Climatology},
	author = {Cazenave, F. and Gosset, M. and Kacou, M. and Alcoba, M. and Fontaine, E. and Duroure, C. and Dolan, B.},
	year = {2016},
	keywords = {Sahel, AMMA-CATCH, IGE, AO},
	pages = {231--249},
}

@article{hassane_can_2016,
	title = {Can daily meteorological measurement of near-surface wind detect climate changes in the {Sahel} ({SE} {Niger}, 1950-1992)?},
	volume = {124},
	doi = {10.1016/j.jaridenv.2015.07.014},
	journal = {Journal of Arid Environments},
	author = {Hassane, Bouba and Durand, Alain and Garba, Zibo and Dieppois, Bastien and Sebag, David and Rajot, Jean-Louis and Diedhiou, Arona and Ngatcha, Benjamin Ngounou and Traore, Abdoulkarim},
	year = {2016},
	keywords = {AMMA-CATCH, ext1, extérieur, niger},
	pages = {91--101},
}

@article{delon_soil_2017,
	title = {Soil and vegetation-atmosphere exchange of {NO}, {NH} 3 , and {N} 2 {O} from field measurements in a semi arid grazed ecosystem in {Senegal}},
	volume = {156},
	issn = {13522310},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S1352231017300948},
	doi = {10.1016/j.atmosenv.2017.02.024},
	language = {en},
	urldate = {2017-03-28},
	journal = {Atmospheric Environment},
	author = {Delon, C. and Galy-Lacaux, C. and Serça, D. and Loubet, B. and Camara, N. and Gardrat, E. and Saneh, I. and Fensholt, R. and Tagesson, T. and Le Dantec, V. and Sambou, B. and Diop, C. and Mougin, E.},
	month = may,
	year = {2017},
	keywords = {AMMA-CATCH, ext1, Senegal},
	pages = {36--51},
}

@article{taylor_frequency_2017,
	title = {Frequency of extreme {Sahelian} storms tripled since 1982 in satellite observations},
	volume = {544},
	issn = {0028-0836, 1476-4687},
	url = {http://www.nature.com/doifinder/10.1038/nature22069},
	doi = {10.1038/nature22069},
	number = {7651},
	urldate = {2017-05-15},
	journal = {Nature},
	author = {Taylor, Christopher M. and Belušić, Danijel and Guichard, Françoise and Parker, Douglas J. and Vischel, Théo and Bock, Olivier and Harris, Phil P. and Janicot, Serge and Klein, Cornelia and Panthou, Gérémy},
	month = apr,
	year = {2017},
	keywords = {Sahel, AMMA-CATCH, ext1, AO, PHYREV},
	pages = {475--478},
}

@article{abdi_evaluating_2017,
	title = {Evaluating {Water} {Controls} on {Vegetation} {Growth} in the {Semi}-{Arid} {Sahel} {Using} {Field} and {Earth} {Observation} {Data}},
	volume = {9},
	issn = {2072-4292},
	url = {http://www.mdpi.com/2072-4292/9/3/294},
	doi = {10.3390/rs9030294},
	language = {en},
	number = {3},
	urldate = {2017-07-24},
	journal = {Remote Sensing},
	author = {Abdi, Abdulhakim and Boke-Olén, Niklas and Tenenbaum, David and Tagesson, Torbern and Cappelaere, Bernard and Ardö, Jonas},
	month = mar,
	year = {2017},
	keywords = {AMMA-CATCH, ext1, Senegal},
	pages = {294},
}

@article{tagesson_modelling_2017,
	title = {Modelling spatial and temporal dynamics of gross primary production in the {Sahel} from earth-observation-based photosynthetic capacity and quantum efficiency},
	volume = {14},
	issn = {1726-4189},
	url = {https://www.biogeosciences.net/14/1333/2017/},
	doi = {10.5194/bg-14-1333-2017},
	language = {en},
	number = {5},
	urldate = {2017-07-24},
	journal = {Biogeosciences},
	author = {Tagesson, Torbern and Ardö, Jonas and Cappelaere, Bernard and Kergoat, Laurent and Abdi, Abdulhakim and Horion, Stéphanie and Fensholt, Rasmus},
	month = mar,
	year = {2017},
	keywords = {Sahel, AMMA-CATCH, ext1, AO},
	pages = {1333--1348},
}

@article{leauthaud_60-year_2017,
	title = {A 60-year reconstructed high-resolution local meteorological data set in {Central} {Sahel} (1950-2009): evaluation, analysis and application to land surface modelling},
	volume = {37},
	issn = {08998418},
	shorttitle = {A 60-year reconstructed high-resolution local meteorological data set in {Central} {Sahel} (1950-2009)},
	url = {http://doi.wiley.com/10.1002/joc.4874},
	doi = {10.1002/joc.4874},
	language = {en},
	number = {5},
	urldate = {2017-07-24},
	journal = {International Journal of Climatology},
	author = {Leauthaud, C. and Cappelaere, B. and Demarty, J. and Guichard, F. and Velluet, C. and Kergoat, L. and Vischel, T. and Grippa, M. and Mouhaimouni, M. and Bouzou Moussa, I. and Mainassara, I. and Sultan, B.},
	month = apr,
	year = {2017},
	keywords = {AMMA-CATCH, Niger, PHYREV, data paper},
	pages = {2699--2718},
}

@article{getirana_streamflows_2017,
	title = {Streamflows over a {West} {African} {Basin} from the {ALMIP2} {Model} {Ensemble}},
	volume = {18},
	issn = {1525-755X, 1525-7541},
	url = {http://journals.ametsoc.org/doi/10.1175/JHM-D-16-0233.1},
	doi = {10.1175/jhm-d-16-0233.1},
	abstract = {Comparing streamflow simulations against observations has become a straightforward way to evaluate a land surface model’s (LSM) ability in simulating water budget within a catchment. Using a mesoscale river routing scheme (RRS), this study evaluates simulated streamflows over the upper Ouémé River basin resulting from 14 LSMs within the framework of phase 2 of the African Monsoon Multidisciplinary Analysis (AMMA) Land Surface Model Intercomparison Project (ALMIP2). The ALMIP2 RRS (ARTS) has been used to route LSM outputs. ARTS is based on the nonlinear Muskingum–Cunge method and a simple deep water infiltration formulation representing water-table recharge as previously observed in that region. Simulations are performed for the 2005–08 period during which ground observations are largely available. Experiments are designed using different ground-based rainfall datasets derived from two interpolation methods: the Thiessen technique and a combined kriging–Lagrangian methodology. LSM-based total runoff (TR) averages vary from 0.07 to 1.97 mm day−1, while optimal TR was estimated as {\textbackslash}textasciitilde0.65 mm day−1. This highly affected the RRS parameterization and streamflow simulations. Optimal Nash–Sutcliffe coefficients for LSM-averaged streamflows varied from 0.66 to 0.92, depending on the gauge station. However, individual LSM performances show a wider range. A more detailed rainfall distribution provided by the kriging–Lagrangian methodology resulted in overall better streamflow simulations. The early runoff generation related to reduced infiltration rates during early rainfall events features as one of the main reasons for poor LSM performances.},
	language = {en},
	number = {7},
	urldate = {2017-07-24},
	journal = {Journal of Hydrometeorology},
	author = {Getirana, Augusto and Boone, Aaron and Peugeot, Christophe and {and ALMIP2 Working Group}},
	month = jul,
	year = {2017},
	keywords = {Hydrologic models, Land surface model, Model comparison, Model evaluation/performance, Parameterization, AMMA-CATCH, ext1, AO, phyrev, Almip2},
	pages = {1831--1845},
}

@article{hinderer_search_2014,
	title = {A search for atmospheric effects on gravity at different time and space scales},
	volume = {80},
	issn = {02643707},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0264370714000179},
	doi = {10.1016/j.jog.2014.02.001},
	abstract = {We investigate in this paper various approaches to correct gravity changes for the effect of atmospheric pressure changes. Two specific locations are considered: Strasbourg (France) as mid-latitude station, where regular pressure fronts occur and Djougou (Benin) as equatorial station with large thermally driven S1 and S2 waves of planetary extent. We first review the classical approaches based on a constant or frequency-dependent admittance using only local pressure and gravity data. We consider then a model of atmospheric loading and show the barometric admittance in terms of elastic, Newtonian and total load, as a function of the distance from the station. We consider both a 2D pressure model (surface loading) and a 2.5D model, where the density decreases with height (standard atmosphere). Assuming horizontal advection in the atmospheric dynamics, we convert this spatially dependent admittance into a frequency-dependent admittance. Using global pressure data from European Centre for Medium-Range Weather Forecasts (ECMWF) at about 12km spatial resolution and 3h sampling, we compute the model-predicted pressure admittance for Djougou and Strasbourg and we simulate the frequency dependence inferred from gravity and pressure observations below 4 cycle per day. A long gravity and pressure data set (1996–2013) from Strasbourg is used to investigate the low frequency part of the pressure admittance while a common 2.5 year data set (August 2010–February 2013) for Strasbourg and Djougou is then analyzed to investigate the high frequency part of the admittance. In both cases, our results are in close agreement with the predictions inferred from an atmospheric 2.5D loading model with a distance–time relationship due to horizontal advection. The frequency dependence of the barometric admittance is explained by the competing contributions of Newtonian attraction and elastic surface deformation according to the distance from the gravimeter. In the far field (low frequencies), the magnitude of the admittance decreases with frequency because of the combined elasticity effect and Newtonian attraction (when the atmosphere is below the horizon) while, on the contrary, in the near field (high frequencies), elasticity becomes negligible and the pressure admittance mainly decreases with increasing frequency because of the decreasing attraction effect of the atmospheric masses inside the cylindrical pressure cell centered on the sensor location of decreasing radius. In the last part, we show that there is variability in time in the pressure admittance for both stations.},
	language = {en},
	urldate = {2017-08-01},
	journal = {Journal of Geodynamics},
	author = {Hinderer, J. and Hector, B. and Boy, J.-P. and Riccardi, U. and Rosat, S. and Calvo, M. and Littel, F.},
	month = oct,
	year = {2014},
	keywords = {Advection, AMMA-CATCH, Gravity, Admittance, Air pressure, Attraction, Elasticity, Frequency, Loading},
	pages = {50--57},
}

@article{diawara_viabilite_2017,
	title = {Viabilité de l'élevage pastoral au {Sahel} : étude de quelques paramètres démographiques des élevages de {Hombori} ({Mali})},
	volume = {26},
	issn = {1166-7699, 1777-5949},
	shorttitle = {Viabilité de l'élevage pastoral au {Sahel}},
	url = {http://www.cahiersagricultures.fr/10.1051/cagri/2017039},
	doi = {10.1051/cagri/2017039},
	number = {4},
	urldate = {2017-09-08},
	journal = {Cahiers Agricultures},
	author = {Diawara, Mamadou O. and Hiernaux, Pierre and Mougin, Eric and Gangneron, Fabrice and Soumaguel, Nogmana},
	month = jul,
	year = {2017},
	keywords = {AMMA-CATCH, Mali},
	pages = {45006},
}

@article{alle_why_2018,
	title = {Why {1D} electrical resistivity techniques can result in inaccurate siting of boreholes in hard rock aquifers and why electrical resistivity tomography must be preferred: the example of {Benin}, {West} {Africa}},
	volume = {139},
	issn = {1464343X},
	shorttitle = {Why {1D} electrical resistivity techniques can result in inaccurate siting of boreholes in hard rock aquifers and why electrical resistivity tomography must be preferred},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S1464343X17304806},
	doi = {10.1016/j.jafrearsci.2017.12.007},
	language = {en},
	urldate = {2018-01-30},
	journal = {Journal of African Earth Sciences},
	author = {Alle, Iboukoun Christian and Descloitres, Marc and Vouillamoz, Jean-Michel and Yalo, Nicaise and Lawson, Fabrice M. A. and Adihou, Akonfa C.},
	month = mar,
	year = {2018},
	keywords = {AMMA-CATCH, LMI REZOC, Benin, PHYREV, socle},
	pages = {341--353},
}

@article{legchenko_interpretation_2016,
	title = {Interpretation of magnetic resonance measurements in the varying earth’s magnetic field},
	volume = {81},
	issn = {0016-8033, 1942-2156},
	url = {http://library.seg.org/doi/10.1190/geo2015-0474.1},
	doi = {10.1190/geo2015-0474.1},
	language = {en},
	number = {4},
	urldate = {2018-01-30},
	journal = {Geophysics},
	author = {Legchenko, Anatoly and Vouillamoz, Jean-Michel and Lawson, Fabrice Messan Amene and Alle, Christian and Descloitres, Marc and Boucher, Marie},
	month = jul,
	year = {2016},
	keywords = {AMMA-CATCH, benin, PHYREV},
	pages = {WB23--WB31},
}

@article{diallo_surface_2017,
	title = {The {Surface} {Energy} {Budget} {Computed} at the {Grid}-{Scale} of a {Climate} {Model} {Challenged} by {Station} {Data} in {West} {Africa}: {GCM} facing {West} {Africa} in situ data},
	volume = {9},
	issn = {19422466},
	shorttitle = {The {Surface} {Energy} {Budget} {Computed} at the {Grid}-{Scale} of a {Climate} {Model} {Challenged} by {Station} {Data} in {West} {Africa}},
	url = {http://doi.wiley.com/10.1002/2017MS001081},
	doi = {10.1002/2017MS001081},
	language = {en},
	number = {7},
	urldate = {2018-02-16},
	journal = {Journal of Advances in Modeling Earth Systems},
	author = {Diallo, F. B. and Hourdin, F. and Rio, C. and Traore, A.-K. and Mellul, L. and Guichard, F. and Kergoat, L.},
	month = nov,
	year = {2017},
	keywords = {AMMA-CATCH, ext1, AO},
	pages = {2710--2738},
}

@article{valentin_niger_1999,
	title = {Niger tiger bush as a natural water harvesting system},
	volume = {37},
	issn = {03418162},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0341816298000617},
	doi = {10.1016/S0341-8162(98)00061-7},
	language = {en},
	number = {1-2},
	urldate = {2018-03-17},
	journal = {CATENA},
	author = {Valentin, C and d'Herbès, J.M},
	month = sep,
	year = {1999},
	keywords = {AMMA-CATCH},
	pages = {231--256},
}

@article{taupin_variabilite_2002,
	title = {Variabilité isotopique des précipitations sahéliennes à différentes échelles de temps à {Niamey} ({Niger}) entre 1992 et 1999 : implication climatique},
	volume = {334},
	issn = {16310713},
	shorttitle = {Variabilité isotopique des précipitations sahéliennes à différentes échelles de temps à {Niamey} ({Niger}) entre 1992 et 1999},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S1631071302017029},
	doi = {10.1016/S1631-0713(02)01702-9},
	language = {fr},
	number = {1},
	urldate = {2018-03-20},
	journal = {Comptes Rendus Geoscience},
	author = {Taupin, Jean-Denis and Gaultier, Gaëlle and Favreau, Guillaume and Leduc, Christian and Marlin, Christelle},
	month = jan,
	year = {2002},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {43--50},
}

@article{lee_enoi_2015,
	title = {{EnOI} {Optimization} for {SMOS} {Soil} {Moisture} {Over} {West} {Africa}},
	volume = {8},
	issn = {1939-1404, 2151-1535},
	url = {http://ieeexplore.ieee.org/document/7085999/},
	doi = {10.1109/JSTARS.2015.2402232},
	number = {4},
	urldate = {2018-03-21},
	journal = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing},
	author = {Lee, Ju Hyoung and Pellarin, Thierry and Kerr, Yann H.},
	month = apr,
	year = {2015},
	keywords = {AMMA-CATCH, ext1, AO, PHYREV},
	pages = {1821--1829},
}

@article{camacho_geov1_2013,
	title = {{GEOV1}: {LAI}, {FAPAR} essential climate variables and {FCOVER} global time series capitalizing over existing products. {Part} 2: {Validation} and intercomparison with reference products},
	volume = {137},
	issn = {00344257},
	shorttitle = {{GEOV1}},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425713000801},
	doi = {10.1016/j.rse.2013.02.030},
	language = {en},
	urldate = {2018-03-25},
	journal = {Remote Sensing of Environment},
	author = {Camacho, Fernando and Cernicharo, Jesús and Lacaze, Roselyne and Baret, Frédéric and Weiss, Marie},
	month = oct,
	year = {2013},
	keywords = {AMMA-CATCH, extérieur},
	pages = {310--329},
}

@article{thauvin_iv_1991,
	title = {{IV}: {EPSAT}-{NIGER} study of rainfall over the {Sahel} at small time steps using a dense network of recording raingauges},
	volume = {5},
	issn = {08856087, 10991085},
	shorttitle = {{IV}},
	url = {http://doi.wiley.com/10.1002/hyp.3360050305},
	doi = {10.1002/hyp.3360050305},
	language = {en},
	number = {3},
	urldate = {2018-03-29},
	journal = {Hydrological Processes},
	author = {Thauvin, V. and Lebel, T.},
	month = jul,
	year = {1991},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {251--260},
}

@article{pomeon_multi-objective_2018,
	title = {Multi-{Objective} {Validation} of {SWAT} for {Sparsely}-{Gauged} {West} {African} {River} {Basins}—{A} {Remote} {Sensing} {Approach}},
	volume = {10},
	issn = {2073-4441},
	url = {http://www.mdpi.com/2073-4441/10/4/451},
	doi = {10.3390/w10040451},
	language = {en},
	number = {4},
	urldate = {2018-04-26},
	journal = {Water},
	author = {Poméon, Thomas and Diekkrüger, Bernd and Springer, Anne and Kusche, Jürgen and Eicker, Annette},
	month = apr,
	year = {2018},
	keywords = {AMMA-CATCH, ext1, extérieur, AO},
	pages = {451},
}

@article{pierre_impact_2018,
	title = {Impact of {Agropastoral} {Management} on {Wind} {Erosion} in {Sahelian} {Croplands}: {Agropastoral} {Management} {Impact} on {Wind} {Erosion} in {Sahelian} {Croplands}},
	volume = {29},
	issn = {10853278},
	shorttitle = {Impact of {Agropastoral} {Management} on {Wind} {Erosion} in {Sahelian} {Croplands}},
	url = {http://doi.wiley.com/10.1002/ldr.2783},
	doi = {10.1002/ldr.2783},
	language = {en},
	number = {3},
	urldate = {2018-06-06},
	journal = {Land Degradation \& Development},
	author = {Pierre, Caroline and Kergoat, Laurent and Hiernaux, Pierre and Baron, Christian and Bergametti, Gilles and Rajot, Jean-Louis and Abdourhamane Toure, Amadou and Okin, Gregory S. and Marticorena, Beatrice},
	month = mar,
	year = {2018},
	keywords = {Sahel, AMMA-CATCH, ext1, AO},
	pages = {800--811},
}

@article{lawin_comparison_2010,
	title = {Comparison of rainfall variability at regional and local scales in the {Upper} {Valley} of {Oueme} in {Benin}},
	volume = {340},
	journal = {IAHS Publ.},
	author = {Lawin, E. and Afouda, A. and Gosset, M. and Lebel, T.},
	year = {2010},
	keywords = {AMMA-CATCH, LMI REZOC, WoS},
	pages = {61--65},
}

@article{gosset_evaluation_2018,
	title = {Evaluation of {TAPEER} daily estimates and other {GPM} era products against dense gauge networks in {West} {Africa}, analyzing ground reference uncertainty},
	issn = {00359009},
	url = {http://doi.wiley.com/10.1002/qj.3335},
	doi = {10.1002/qj.3335},
	language = {en},
	urldate = {2018-07-24},
	journal = {Quarterly Journal of the Royal Meteorological Society},
	author = {Gosset, Marielle and Alcoba, Matias and Roca, Remy and Cloché, Sophie and Urbani, Guillaume},
	month = jun,
	year = {2018},
	keywords = {AMMA-CATCH, AO},
}

@article{leauthaud_modelling_2018,
	title = {Modelling the growth of floodplain grasslands to explore the impact of changing hydrological conditions on vegetation productivity},
	volume = {387},
	issn = {03043800},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0304380018303119},
	doi = {10.1016/j.ecolmodel.2018.09.015},
	language = {en},
	urldate = {2018-11-16},
	journal = {Ecological Modelling},
	author = {Leauthaud, C. and Kergoat, L. and Hiernaux, P. and Grippa, M. and Musila, W. and Duvail, S. and Albergel, J.},
	month = nov,
	year = {2018},
	keywords = {AMMA-CATCH},
	pages = {220--237},
}

@article{dickson_analysis_2018,
	title = {Analysis and numerical modelling of large-scale controls on aquifer structure and hydrogeological properties in the {African} basement ({Benin}, {West} {Africa})},
	issn = {0305-8719, 2041-4927},
	url = {http://sp.lyellcollection.org/lookup/doi/10.1144/SP479.2},
	doi = {10.1144/SP479.2},
	language = {en},
	urldate = {2018-11-21},
	journal = {Geological Society, London, Special Publications},
	author = {Dickson, Neil E. M. and Comte, Jean-Christophe and Koussoube, Youssouf and Ofterdinger, Ulrich S. and Vouillamoz, Jean-Michel},
	month = may,
	year = {2018},
	keywords = {AMMA-CATCH, ext1, LMI REZOC, benin, PHYREV},
	pages = {SP479.2},
}

@article{lebel_climat_2005,
	title = {Climat et cycle de l'eau en zone tropicale : un problème d'échelle},
	volume = {337},
	issn = {16310713},
	shorttitle = {Climat et cycle de l'eau en zone tropicale},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S1631071304002810},
	doi = {10.1016/j.crte.2004.08.011},
	language = {fr},
	number = {1-2},
	urldate = {2018-11-21},
	journal = {Comptes Rendus Geoscience},
	author = {Lebel, Thierry and Vischel, Théo},
	month = jan,
	year = {2005},
	keywords = {AMMA-CATCH},
	pages = {29--38},
}

@article{hssaine_combining_2018,
	title = {Combining a {Two} {Source} {Energy} {Balance} {Model} {Driven} by {MODIS} and {MSG}-{SEVIRI} {Products} with an {Aggregation} {Approach} to {Estimate} {Turbulent} {Fluxes} over {Sparse} and {Heterogeneous} {Vegetation} in {Sahel} {Region} ({Niger})},
	volume = {10},
	issn = {2072-4292},
	url = {http://www.mdpi.com/2072-4292/10/6/974},
	doi = {10.3390/rs10060974},
	language = {en},
	number = {6},
	urldate = {2018-11-23},
	journal = {Remote Sensing},
	author = {Hssaine, Bouchra and Ezzahar, Jamal and Jarlan, Lionel and Merlin, Olivier and Khabba, Said and Brut, Aurore and Er-Raki, Salah and Elfarkh, Jamal and Cappelaere, Bernard and Chehbouni, Ghani},
	month = jun,
	year = {2018},
	keywords = {AMMA-CATCH, ext1, sahel},
	pages = {974},
}

@article{gaillardet_ozcar_2018,
	title = {{OZCAR}: {The} {French} {Network} of {Critical} {Zone} {Observatories}},
	volume = {17},
	issn = {1539-1663},
	shorttitle = {{OZCAR}},
	url = {https://dl.sciencesocieties.org/publications/vzj/abstracts/17/1/180067},
	doi = {10.2136/vzj2018.04.0067},
	language = {en},
	number = {1},
	urldate = {2018-12-05},
	journal = {Vadose Zone Journal},
	author = {Gaillardet, J. and Braud, I. and Hankard, F. and Anquetin, S. and Bour, O. and Dorfliger, N. and de Dreuzy, J.R. and Galle, S. and Galy, C. and Gogo, S. and Gourcy, L. and Habets, F. and Laggoun, F. and Longuevergne, L. and Le Borgne, T. and Naaim-Bouvet, F. and Nord, G. and Simonneaux, V. and Six, D. and Tallec, T. and Valentin, C. and Abril, G. and Allemand, P. and Arènes, A. and Arfib, B. and Arnaud, L. and Arnaud, N. and Arnaud, P. and Audry, S. and Comte, V. Bailly and Batiot, C. and Battais, A. and Bellot, H. and Bernard, E. and Bertrand, C. and Bessière, H. and Binet, S. and Bodin, J. and Bodin, X. and Boithias, L. and Bouchez, J. and Boudevillain, B. and Bouzou Moussa, I. and Branger, F. and Braun, J. J. and Brunet, P. and Caceres, B. and Calmels, D. and Cappelaere, B. and Celle-Jeanton, H. and Chabaux, F. and Chalikakis, K. and Champollion, C. and Copard, Y. and Cotel, C. and Davy, P. and Deline, P. and Delrieu, G. and Demarty, J. and Dessert, C. and Dumont, M. and Emblanch, C. and Ezzahar, J. and Estèves, M. and Favier, V. and Faucheux, M. and Filizola, N. and Flammarion, P. and Floury, P. and Fovet, O. and Fournier, M. and Francez, A. J. and Gandois, L. and Gascuel, C. and Gayer, E. and Genthon, C. and Gérard, M. F. and Gilbert, D. and Gouttevin, I. and Grippa, M. and Gruau, G. and Jardani, A. and Jeanneau, L. and Join, J. L. and Jourde, H. and Karbou, F. and Labat, D. and Lagadeuc, Y. and Lajeunesse, E. and Lastennet, R. and Lavado, W. and Lawin, E. and Lebel, T. and Le Bouteiller, C. and Legout, C. and Lejeune, Y. and Le Meur, E. and Le Moigne, N. and Lions, J. and Lucas, A. and Malet, J. P. and Marais-Sicre, C. and Maréchal, J. C. and Marlin, C. and Martin, P. and Martins, J. and Martinez, J. M. and Massei, N. and Mauclerc, A. and Mazzilli, N. and Molénat, J. and Moreira-Turcq, P. and Mougin, E. and Morin, S. and Ngoupayou, J. Ndam and Panthou, G. and Peugeot, C. and Picard, G. and Pierret, M. C. and Porel, G. and Probst, A. and Probst, J. L. and Rabatel, A. and Raclot, D. and Ravanel, L. and Rejiba, F. and René, P. and Ribolzi, O. and Riotte, J. and Rivière, A. and Robain, H. and Ruiz, L. and Sanchez-Perez, J. M. and Santini, W. and Sauvage, S. and Schoeneich, P. and Seidel, J. L. and Sekhar, M. and Sengtaheuanghoung, O. and Silvera, N. and Steinmann, M. and Soruco, A. and Tallec, G. and Thibert, E. and Lao, D. Valdes and Vincent, C. and Viville, D. and Wagnon, P. and Zitouna, R.},
	year = {2018},
	keywords = {AMMA-CATCH, ext1, OZCAR, PHYREV},
	pages = {0},
}

@article{blanchet_trend_2018,
	title = {Trend in the {Co}-{Occurrence} of {Extreme} {Daily} {Rainfall} in {West} {Africa} {Since} 1950},
	issn = {2169897X},
	url = {http://doi.wiley.com/10.1002/2017JD027219},
	doi = {10.1002/2017JD027219},
	language = {en},
	urldate = {2019-02-07},
	journal = {Journal of Geophysical Research: Atmospheres},
	author = {Blanchet, Juliette and Aly, Claire and Vischel, Théo and Panthou, Gérémy and Sané, Youssouph and Diop Kane, Mariane},
	month = feb,
	year = {2018},
	keywords = {AMMA-CATCH, AO, PHYREV, sahel},
}

@article{gibon_millet_2018,
	title = {Millet yield estimates in the {Sahel} using satellite derived soil moisture time series},
	volume = {262},
	issn = {01681923},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0168192318302223},
	doi = {10.1016/j.agrformet.2018.07.001},
	language = {en},
	urldate = {2019-02-07},
	journal = {Agricultural and Forest Meteorology},
	author = {Gibon, François and Pellarin, Thierry and Román-Cascón, Carlos and Alhassane, Agali and Traoré, Seydou and Kerr, Yann and Lo Seen, Danny and Baron, Christian},
	month = nov,
	year = {2018},
	keywords = {Sahel, AMMA-CATCH, AO, PHYREV},
	pages = {100--109},
}

@article{hector_hydrological_2018,
	title = {Hydrological functioning of western {African} inland valleys explored with a critical zone model},
	volume = {22},
	issn = {1607-7938},
	url = {https://www.hydrol-earth-syst-sci.net/22/5867/2018/},
	doi = {10.5194/hess-22-5867-2018},
	language = {en},
	number = {11},
	urldate = {2019-02-07},
	journal = {Hydrology and Earth System Sciences},
	author = {Hector, Basile and Cohard, Jean-Martial and Séguis, Luc and Galle, Sylvie and Peugeot, Christophe},
	month = nov,
	year = {2018},
	keywords = {AMMA-CATCH, Benin, PHYREV},
	pages = {5867--5888},
}

@article{sane_intensitydurationfrequency_2018,
	title = {Intensity–duration–frequency ({IDF}) rainfall curves in {Senegal}},
	volume = {18},
	issn = {1684-9981},
	url = {https://www.nat-hazards-earth-syst-sci.net/18/1849/2018/},
	doi = {10.5194/nhess-18-1849-2018},
	language = {en},
	number = {7},
	urldate = {2019-02-07},
	journal = {Natural Hazards and Earth System Sciences},
	author = {Sane, Youssouph and Panthou, Geremy and Bodian, Ansoumana and Vischel, Theo and Lebel, Thierry and Dacosta, Honore and Quantin, Guillaume and Wilcox, Catherine and Ndiaye, Ousmane and Diongue-Niang, Aida and Diop Kane, Mariane},
	month = jul,
	year = {2018},
	keywords = {AMMA-CATCH, Senegal, AO, PHYREV},
	pages = {1849--1866},
}

@article{mougin_leaf_2019,
	title = {A leaf area index data set acquired in {Sahelian} rangelands of {Gourma} in {Mali} over the 2005–2017 period},
	volume = {11},
	issn = {1866-3591},
	url = {https://www.earth-syst-sci-data.net/11/675/2019/},
	doi = {10.5194/essd-11-675-2019},
	language = {en},
	number = {2},
	urldate = {2019-04-19},
	journal = {Earth System Science Data},
	author = {Mougin, Eric and Diawara, Mamadou Oumar and Soumaguel, Nogmana and Maiga, Ali Amadou and Demarez, Valerie and Hiernaux, Pierre and Grippa, Manuela and Chaffard, Veronique and Ba, Abdramane},
	year = {2019},
	keywords = {AMMA-CATCH, data paper},
	pages = {675--686},
}

@article{al-yaari_assessment_2019,
	title = {Assessment and inter-comparison of recently developed/reprocessed microwave satellite soil moisture products using {ISMN} ground-based measurements},
	volume = {224},
	issn = {0034-4257},
	url = {http://www.sciencedirect.com/science/article/pii/S003442571930063X},
	doi = {10.1016/j.rse.2019.02.008},
	abstract = {Soil moisture (SM) is a key state variable in understanding the climate system through its control on the land surface energy, water budget partitioning, and the carbon cycle. Monitoring SM at regional scale has become possible thanks to microwave remote sensing. In the past two decades, several satellites were launched carrying on board either radiometer (passive) or radar (active) or both sensors in different frequency bands with various spatial and temporal resolutions. Soil moisture algorithms are in rapid development and their improvements/revisions are ongoing. The latest SM retrieval products and versions of products that have been recently released are not yet, to our knowledge, comprehensively evaluated and inter-compared over different ecoregions and climate conditions. The aim of this paper is to comprehensively evaluate the most recent microwave-based SM retrieval products available from NASA's (National Aeronautics and Space Administration) SMAP (Soil Moisture Active Passive) satellite, ESA's led mission (European Space Agency) SMOS (Soil Moisture and Ocean Salinity) satellite, ASCAT (Advanced Scatterometer) sensor on board the meteorological operational (Metop) platforms Metop-A and Metop-B, and the ESA Climate Change Initiative (CCI) blended long-term SM time series. More specifically, in this study we compared SMAPL3 V4, SMOSL3 V300, SMOSL2 V650, ASCAT H111, and CCI V04.2 and the new SMOS-IC (V105) SM product. This evaluation was achieved using four statistical scores: Pearson correlation (considering both original observations and anomalies), RMSE, unbiased RMSE, and Bias between remotely-sensed SM retrievals and ground-based measurements from {\textbackslash}textgreater1000 stations from 17 monitoring networks, spread over the globe, disseminated through the International Soil Moisture Network (ISMN). The analysis reveals that the performance of the remotely-sensed SM retrievals generally varies depending on ecoregions, land cover types, climate conditions, and between the monitoring networks. It also reveals that temporal sampling of the data, the frequency of data in time and the spatial coverage, affect the performance metrics. Overall, the performance of SMAP and SMOS-IC products compared slightly better with respect to the ISMN in situ observations than the other remotely-sensed products.},
	urldate = {2019-04-26},
	journal = {Remote Sensing of Environment},
	author = {Al-Yaari, A. and Wigneron, J. -P. and Dorigo, W. and Colliander, A. and Pellarin, T. and Hahn, S. and Mialon, A. and Richaume, P. and Fernandez-Moran, R. and Fan, L. and Kerr, Y. H. and De Lannoy, G.},
	month = apr,
	year = {2019},
	keywords = {Soil moisture, AMMA-CATCH, ext1, IGE, Active microwave remote sensing, Evaluation, International soil moisture network, Passive microwave remote sensing, Review},
	pages = {289--303},
}

@article{hiernaux_expanding_2019,
	title = {Expanding networks of field hedges in densely populated landscapes in the {Sahel}},
	volume = {440},
	issn = {0378-1127},
	url = {http://www.sciencedirect.com/science/article/pii/S0378112718320115},
	doi = {10.1016/j.foreco.2019.03.016},
	abstract = {Changing woody plant density across agricultural landscapes of the Sudano-Sahelian region is a debated issue. This paper reports the results of an investigation on the contribution of field hedges to overall woody plant density. Hedges separating individual cropped parcels were studied within village agropastoral territories in the Dantiandou district in western Niger. In 1992, field hedges were mapped over the study area using aerial photography and in 2016, using high resolution Google Earth imagery. In 1992, field hedge length was equal to 1006 km within 435 km2 of croplands, equivalent to 2.3 km km−2. In 2016, 17.5\% of these hedges had disappeared, but 1591 km of new hedges were observed resulting in an increased density of hedges to 5.6 km km−2. In 24 years, hedges had increased at a mean annual rate of 3.7\% likely associated with the splitting of crop fields by inheritance. The composition and productivity of hedges were also monitored in 1996, 2010 and 2015. All trees (maximum height ≥ 4 m), shrubs ({\textbackslash}textless4 m) and tussock perennial grasses were recorded within twelve field hedge samples of 200 m each. Field measurements were used to estimate basal area, crown area, foliage mass and wood mass of each woody plant within the sampled hedges. No significant trends were found between 1996 and 2015 in woody plant density, basal area, crown cover, wood and foliage masses across all monitored hedges. However, overall means hide a slight decrease in tree contributions, while shrub contributions first increased and then decreased. They also mask contradictory trends among sites most likely related to different rates of shrub coppicing and tree cutting. The woody species composition of the hedges is poor with an increase of Combretum glutinosum to the detriment of Guiera senegalensis over the study period. Multiplying the hedge sample statistics by the changing lengths of field hedges in the study area provides estimates of the contribution of the hedge woody plants to the woody plant population at a landscape scale. Between 1992 and 2016, field hedges contributed to increases of woody plant density by 3.9\%, basal areas by 5.4\%, crown cover by 2.7\%, leading to 6.1\% annual increase in foliage mass and 8.8\% increase in wood mass.},
	urldate = {2019-04-26},
	journal = {Forest Ecology and Management},
	author = {Hiernaux, Pierre and Adamou, Kalilou and Moumouni, Oumarou and Turner, Matthew D. and Tong, Xiaoye and Savadogo, Patrice and Mougin, Eric and Malam Issa, Oumarou},
	month = may,
	year = {2019},
	keywords = {AMMA-CATCH, Deforestation, Agroforestry, Bocage, Hedgerow, Land tenure, Tropical Africa},
	pages = {178--188},
}

@article{roca_quantifying_2018,
	title = {Quantifying the contribution of the {Megha}‐{Tropiques} mission to the estimation of daily accumulated rainfall in the {Tropics}},
	volume = {144},
	issn = {0035-9009, 1477-870X},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/qj.3327},
	doi = {10.1002/qj.3327},
	language = {en},
	number = {S1},
	urldate = {2019-04-26},
	journal = {Quarterly Journal of the Royal Meteorological Society},
	author = {Roca, Rémy and Taburet, Nicolas and Lorant, Estelle and Chambon, Philippe and Alcoba, Matias and Brogniez, Hélène and Cloché, Sophie and Dufour, Christophe and Gosset, Marielle and Guilloteau, Clément},
	month = nov,
	year = {2018},
	keywords = {AMMA-CATCH, ext1},
	pages = {49--63},
}

@article{raso_how_2019,
	title = {How to evaluate a monitoring system for adaptive policies: criteria for signposts selection and their model-based evaluation},
	volume = {153},
	issn = {0165-0009, 1573-1480},
	shorttitle = {How to evaluate a monitoring system for adaptive policies},
	url = {http://link.springer.com/10.1007/s10584-018-2355-3},
	doi = {10.1007/s10584-018-2355-3},
	language = {en},
	number = {1-2},
	urldate = {2019-04-29},
	journal = {Climatic Change},
	author = {Raso, Luciano and Kwakkel, Jan and Timmermans, Jos and Panthou, Geremy},
	month = mar,
	year = {2019},
	keywords = {AMMA-CATCH, ext1, LMI REZOC, IGE},
	pages = {267--283},
}

@article{delon_modelling_2019,
	title = {Modelling land–atmosphere daily exchanges of {NO}, {NH3}, and {CO2} in a semi-arid grazed ecosystem in {Senegal}},
	volume = {16},
	issn = {1726-4189},
	url = {https://www.biogeosciences.net/16/2049/2019/},
	doi = {10.5194/bg-16-2049-2019},
	language = {en},
	number = {9},
	urldate = {2019-05-16},
	journal = {Biogeosciences},
	author = {Delon, Claire and Galy-Lacaux, Corinne and Serça, Dominique and Personne, Erwan and Mougin, Eric and Adon, Marcellin and Le Dantec, Valérie and Loubet, Benjamin and Fensholt, Rasmus and Tagesson, Torbern},
	month = may,
	year = {2019},
	keywords = {AMMA-CATCH, ext1},
	pages = {2049--2077},
}

@article{faye_soil_2018,
	title = {Soil moisture estimation in {Ferlo} region ({Senegal}) using radar ({ENVISAT}/{ASAR}) and optical ({SPOT}/{VEGETATION}) data},
	volume = {21},
	issn = {11109823},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S1110982317301047},
	doi = {10.1016/j.ejrs.2017.11.005},
	language = {en},
	urldate = {2019-05-24},
	journal = {The Egyptian Journal of Remote Sensing and Space Science},
	author = {Faye, Gayane and Frison, Pierre-Louis and Diouf, Abdou-Aziz and Wade, Souleye and Kane, Cheikh Amidou and Fussi, Fabio and Jarlan, Lionel and Niang, Magatte Fary Kani and Ndione, Jacques André and Rudant, Jean Paul and Mougin, Eric},
	month = jul,
	year = {2018},
	keywords = {AMMA-CATCH, Senegal},
	pages = {S13--S22},
}

@article{diawara_effets_2018,
	title = {Effets de la pâture sur la dynamique de la végétation herbacée au {Sahel} ({Gourma}, {Mali}) : une approche par modélisation},
	volume = {27},
	issn = {1166-7699, 1777-5949},
	shorttitle = {Effets de la pâture sur la dynamique de la végétation herbacée au {Sahel} ({Gourma}, {Mali})},
	url = {https://www.cahiersagricultures.fr/10.1051/cagri/2018002},
	doi = {10.1051/cagri/2018002},
	number = {1},
	urldate = {2019-05-24},
	journal = {Cahiers Agricultures},
	author = {Diawara, Mamadou Oumar and Hiernaux, Pierre and Mougin, Eric and Grippa, Manuela and Delon, Claire and Diakité, Hawa Salif},
	month = jan,
	year = {2018},
	keywords = {AMMA-CATCH, Mali},
	pages = {15010},
}

@article{normandin_evolution_2018,
	title = {Evolution of the {Performances} of {Radar} {Altimetry} {Missions} from {ERS}-2 to {Sentinel}-{3A} over the {Inner} {Niger} {Delta}},
	volume = {10},
	issn = {2072-4292},
	url = {http://www.mdpi.com/2072-4292/10/6/833},
	doi = {10.3390/rs10060833},
	language = {en},
	number = {6},
	urldate = {2019-05-24},
	journal = {Remote Sensing},
	author = {Normandin, Cassandra and Frappart, Frédéric and Diepkilé, Adama Telly and Marieu, Vincent and Mougin, Eric and Blarel, Fabien and Lubac, Bertrand and Braquet, Nadine and Ba, Abdramane},
	month = may,
	year = {2018},
	keywords = {AMMA-CATCH, ext1, Mali, Inner Delta Niger},
	pages = {833},
}

@article{fatras_impact_2018,
	title = {Impact of {Surface} {Soil} {Moisture} {Variations} on {Radar} {Altimetry} {Echoes} at {Ku} and {Ka} {Bands} in {Semi}-{Arid} {Areas}},
	volume = {10},
	issn = {2072-4292},
	url = {http://www.mdpi.com/2072-4292/10/4/582},
	doi = {10.3390/rs10040582},
	language = {en},
	number = {4},
	urldate = {2019-05-24},
	journal = {Remote Sensing},
	author = {Fatras, Christophe and Borderies, Pierre and Frappart, Frédéric and Mougin, Eric and Blumstein, Denis and Niño, Fernando},
	month = apr,
	year = {2018},
	keywords = {AMMA-CATCH, ext1, sahel},
	pages = {582},
}

@article{leauthaud_influence_2019,
	title = {Influence of {Floods} and {Growth} {Duration} on the {Productivity} of {Wet} {Grasslands} of {Echinochloa} stagnina ({Retz}) {P}. {Beauv}. in an {East} {African} {Floodplain}},
	volume = {39},
	issn = {0277-5212, 1943-6246},
	url = {http://link.springer.com/10.1007/s13157-019-01148-9},
	doi = {10.1007/s13157-019-01148-9},
	language = {en},
	number = {5},
	urldate = {2020-03-20},
	journal = {Wetlands},
	author = {Leauthaud, C. and Hiernaux, P. and Musila, W. and Kergoat, L. and Grippa, M. and Duvail, S. and Albergel, J. and Rode, N. O.},
	month = oct,
	year = {2019},
	keywords = {AMMA-CATCH},
	pages = {935--944},
}

@article{massazza_flood_2019,
	title = {Flood {Hazard} {Scenarios} of the {Sirba} {River} ({Niger}): {Evaluation} of the {Hazard} {Thresholds} and {Flooding} {Areas}},
	volume = {11},
	issn = {2073-4441},
	shorttitle = {Flood {Hazard} {Scenarios} of the {Sirba} {River} ({Niger})},
	url = {https://www.mdpi.com/2073-4441/11/5/1018},
	doi = {10.3390/w11051018},
	abstract = {In Sahelian countries, a vast number of people are still affected every year by flood despite the efforts to prevent or mitigate these catastrophic events. This phenomenon is exacerbated by the incessant population growth and the increase of extreme natural events. Hence, the development of flood management strategies such as flood hazard mapping and Early Warning Systems has become a crucial objective for the affected nations. This study presents a comprehensive hazard assessment of the Nigerien reach of the Sirba River, the main tributary Middle Niger River. Hazard thresholds were defined both on hydrological analysis and field effects, according to national guidelines. Non-stationary analyses were carried out to consider changes in the hydrological behavior of the Sirba basin over time. Data from topographical land surveys and discharge gauges collected during the 2018 dry and wet seasons were used to implement the hydraulic numerical model of the analyzed reach. The use of the proposed hydraulic model allowed the delineation of flood hazard maps as well the calculation of the flood propagation time from the upstream hydrometric station and the validation of the rating curves of the two gauging sites. These significative outcomes will allow the implementation of the Early Warning System for the river flood hazard and risk reduction plans preparation for each settlement.},
	language = {en},
	number = {5},
	urldate = {2020-03-23},
	journal = {Water},
	author = {Massazza, Giovanni and Tamagnone, Paolo and Wilcox, Catherine and Belcore, Elena and Pezzoli, Alessandro and Vischel, Theo and Panthou, Gérémy and Housseini Ibrahim, Mohamed and Tiepolo, Maurizio and Tarchiani, Vieri and Rosso, Maurizio},
	month = may,
	year = {2019},
	keywords = {Sahel, AMMA-CATCH, ext1, IGE},
	pages = {1018},
}

@article{delogu_evaluation_2018,
	title = {Evaluation of the {SPARSE} {Dual}-{Source} {Model} for {Predicting} {Water} {Stress} and {Evapotranspiration} from {Thermal} {Infrared} {Data} over {Multiple} {Crops} and {Climates}},
	volume = {10},
	issn = {2072-4292},
	url = {http://www.mdpi.com/2072-4292/10/11/1806},
	doi = {10.3390/rs10111806},
	abstract = {Using surface temperature as a signature of the surface energy balance is a way to quantify the spatial distribution of evapotranspiration and water stress. In this work, we used the new dual-source model named Soil Plant Atmosphere and Remote Sensing Evapotranspiration (SPARSE) based on the Two Sources Energy Balance (TSEB) model rationale which solves the surface energy balance equations for the soil and the canopy. SPARSE can be used (i) to retrieve soil and vegetation stress levels from known surface temperature and (ii) to predict transpiration, soil evaporation, and surface temperature for given stress levels. The main innovative feature of SPARSE is that it allows to bound each retrieved individual flux component (evaporation and transpiration) by its corresponding potential level deduced from running the model in prescribed potential conditions, i.e., a maximum limit if the surface water availability is not limiting. The main objective of the paper is to assess the SPARSE model predictions of water stress and evapotranspiration components for its two proposed versions (the “patch” and “layer” resistances network) over 20 in situ data sets encompassing distinct vegetation and climate. Over a large range of leaf area index values and for contrasting vegetation stress levels, SPARSE showed good retrieval performances of evapotranspiration and sensible heat fluxes. For cereals, the layer version provided better latent heat flux estimates than the patch version while both models showed similar performances for sparse crops and forest ecosystems. The bounded layer version of SPARSE provided the best estimates of latent heat flux over different sites and climates. Broad tendencies of observed and retrieved stress intensities were well reproduced with a reasonable difference obtained for most of the points located within a confidence interval of 0.2. The synchronous dynamics of observed and retrieved estimates underlined that the SPARSE retrieved water stress estimates from Thermal Infra-Red data were relevant tools for stress detection.},
	language = {en},
	number = {11},
	urldate = {2020-10-22},
	journal = {Remote Sensing},
	author = {Delogu, Emilie and Boulet, Gilles and Olioso, Albert and Garrigues, Sébastien and Brut, Aurore and Tallec, Tiphaine and Demarty, Jérôme and Soudani, Kamel and Lagouarde, Jean-Pierre},
	month = nov,
	year = {2018},
	keywords = {AMMA-CATCH, ext1},
	pages = {1806},
}

@article{lebel_projet_2008,
	title = {Le projet {AMMA}, un exemple d’étude intégré et multidisciplinaire sur un système climatique régional},
	copyright = {© Société Hydrotechnique de France, 2008},
	issn = {0018-6368, 1958-5551},
	url = {https://www-shf-lhb-org.insu.bib.cnrs.fr/articles/lhb/abs/2008/02/lhb2008015/lhb2008015.html},
	doi = {10.1051/lhb:2008015},
	abstract = {Initiated by the French community, the AMMA international project aims to improve our knowledge and understanding of the West African monsoon and its variability with an emphasis on daily-to-interannual timescales. AMMA is motivated by an interest in fundamental scientific issues and by the societal need for improved prediction of the WAM and its impacts on water resources, health and food security for West African nations.},
	language = {fr},
	number = {2},
	urldate = {2020-10-22},
	journal = {La Houille Blanche},
	author = {Lebel, Thierry and Redelsperger, Jean-Luc},
	month = apr,
	year = {2008},
	keywords = {AMMA, AMMA-CATCH},
	pages = {38--44},
}

@article{gallee_high-resolution_2004,
	title = {A high-resolution simulation of a {West} {African} rainy season using a regional climate model},
	volume = {109},
	copyright = {Copyright 2004 by the American Geophysical Union.},
	issn = {2156-2202},
	url = {http://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2003JD004020},
	doi = {10.1029/2003JD004020},
	abstract = {The regional climate model Modèle Atmosphérique Régional (MAR) is applied to West Africa and the year 1992 is simulated. MAR reproduces the observed intraseasonal variations of rainfall. It is suggested that such a phenomenon is associated with oscillations between a weak and a strong regime of the Hadley cell. The later is correlated with a stronger meridional gradient of moist static energy in the planetary boundary layer and is responsible for an enhanced convergence of this quantity and a subsequent increase of convection and rain. An enhanced consumption of moist static energy and finally a weakening of the meridional circulation result. The meridional gradient of the moist static energy is restored by surface processes. The model also simulates the observed abrupt northward shift of the rainband in the first half of July. The spatial variability of the simulated monthly mean rainfall is in good agreement with the observations, although the model overestimates rainfall in some places from the beginning of August. Time series of daily mean rainfall are averaged over two 2.5° × 2.5° grid meshes in the Niamey region and in the Ouémé high valley. Maxima reaching up to 40 mm/day are found in both areas, as in the observations. Atmospheric variables such as temperature and wind are briefly compared with the European Center for Medium-Range Weather Forecasting reanalyses. The main (cold) biases are located where the hydrological cycle simulated by MAR is too strong.},
	language = {en},
	number = {D5},
	urldate = {2020-10-22},
	journal = {Journal of Geophysical Research: Atmospheres},
	author = {Gallée, H. and Moufouma‐Okia, W. and Bechtold, P. and Brasseur, O. and Dupays, I. and Marbaix, P. and Messager, C. and Ramel, R. and Lebel, T.},
	year = {2004},
	keywords = {West Africa, AMMA, rainfall, AMMA-CATCH, regional climate model},
}

@article{guillot_disaggregation_1999,
	title = {Disaggregation of {Sahelian} mesoscale convective system rain fields: {Further} developments and validation},
	volume = {104},
	copyright = {Copyright 1999 by the American Geophysical Union.},
	issn = {2156-2202},
	shorttitle = {Disaggregation of {Sahelian} mesoscale convective system rain fields},
	url = {http://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/1999JD900986},
	doi = {10.1029/1999JD900986},
	abstract = {Bridging the gaps between the GCM scales and the hydrological scales is a key issue when studying the impacts of potential climate changes on the water resources and, more generally, the links between climate variability and hydrological variability. This is especially true in tropical regions where (1) rainfall is highly variable in space and time due to its convective nature, and (2) measurements are scarce. Using high-resolution data collected in the semi arid region of Niamey, Niger, Lebel et al. [1998] have proposed a space-time model (the LBC model), allowing the disaggregation of large-scale estimates produced either from satellite images or general circulation model (GCM) outputs. The behavior of this model was shown to be globally satisfying when tested on a small number of selected Sahelian mesoscale convective complexes (SMCCs). However, to be of use in simulation studies of the impact of climate changes as predicted by GCMs or in an operational context where only satellite data are readily available, a more systematic validation was required. Also, the initial version of the model was intended at dealing with SMCCs only, leaving aside the other convective systems displaying a less coherent spatial structure. This led to develop a new version of the LBC model, presented here, characterized by the following improvements: (1) a more precise modeling of the spatial structure of the total storm rain fields by taking into account their anisotropy and using a nested covariance, (2) a better representation of the storm kinematic by dealing with arrival times of rain rather than with speeds of movement, (3) a revision of the parameters used to define the standard hyetograph which is the basis of the time disaggregation algorithm. This new version of the model has two main advantages as compared to the older one: (1) the capacity of dealing with every kind of Sahelian mesoscale convective systems (SMCSs), which account for more than 90\% of the total annual rainfall in the region; (2) the possibility of using the model both in simulation and in disaggregation modes. The validation of the model is carried out by comparing the rainfall statistics at various scales of aggregation, for a set of 170 observed SMCSs (corresponding to the 1990–1993 operating period) and a set of 170 simulated SMCSs.},
	language = {en},
	number = {D24},
	urldate = {2020-10-22},
	journal = {Journal of Geophysical Research: Atmospheres},
	author = {Guillot, Gilles and Lebel, Thierry},
	year = {1999},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {31533--31551},
}

@article{lebel_rainfall_1999,
	series = {American {Meteorological} {Society}},
	title = {Rainfall {Estimation} in the {Sahel}: {What} {Is} the {Ground} {Truth}?},
	volume = {38},
	url = {https://journals-ametsoc-org.insu.bib.cnrs.fr/jamc/article/38/5/555/15781/Rainfall-Estimation-in-the-Sahel-What-Is-the},
	doi = {10.1175/1520-0450(1999)038<0555:REITSW>2.0.CO;2},
	number = {5},
	urldate = {2020-10-22},
	journal = {Journal of Applied Meteorology and Climatology},
	author = {Lebel, T. and Amani, A.},
	year = {1999},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {555--568},
}

@article{guillot_approximation_1999,
	title = {Approximation of {Sahelian} rainfall fields with meta-{Gaussian} random functions},
	volume = {13},
	issn = {1436-3240, 1436-3259},
	url = {http://link.springer.com/10.1007/s004770050035},
	doi = {10.1007/s004770050035},
	number = {1-2},
	urldate = {2020-10-22},
	journal = {Stochastic Environmental Research and Risk Assessment (SERRA)},
	author = {Guillot, G. and Lebel, T.},
	month = apr,
	year = {1999},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {113--130},
}

@article{damato_characteristics_1998,
	title = {On the characteristics of the rainfall events in the {Sahel} with a view to the analysis of climatic variability},
	volume = {18},
	copyright = {Copyright © 1998 Royal Meteorological Society},
	issn = {1097-0088},
	url = {http://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/%28SICI%291097-0088%28199807%2918%3A9%3C955%3A%3AAID-JOC236%3E3.0.CO%3B2-6},
	doi = {10.1002/(SICI)1097-0088(199807)18:9<955::AID-JOC236>3.0.CO;2-6},
	abstract = {The lack of appropriate data has long been a major obstacle to the study of the Sahelian rainfall at the event scale. In this paper, use is made of the EPSAT-Niger recording rain-gauge data to characterize the convective rain events of the central Sahel. Although some considerations lead to the identification of two main types of mesoscale convective systems, it is shown here that the most relevant stratification in terms of statistical analysis of the event rainfall distribution is between the events of the margins and those of the core of the rainy season. In fact, the average storm rain-depth appears to be non-stationary in time, with storm rain-depths slightly higher in the core of the rainy season than on the margins. Separation between the core and the margins thus allows the fitting of an exponential model to the observed storm rain-depth distributions of each period (core and margins), although a better fit would certainly be obtained if a proper modelling of the time non-stationarity was carried out. It is then shown that there is little, if any, correlation between the mean storm rain-depth of a given year and the overall abundance of the corresponding rainy season. This is a validation of previous works, which reached the same conclusion using daily rainfall data only. One major result of this work is that the statistics characterizing the rain events in the Sahel display little fluctuations, either in space or from year-to-year, as compared with those observed for the total seasonal rainfall. Each year and at each station the average storm rainfall remains close to 12 mm during the margins of the rainy season and close to 15 mm in the core. During the same period, the average seasonal rainfall over the study area ranged from 400 to 660 mm and for any given year the ratio between the maximum and the minimum point seasonal rainfall was of the order of 2. It is therefore concluded that the main source of rainfall variability in the Sahel is linked to the variability in the number of events rather than in the magnitude of these events. © 1998 Royal Meteorological Society},
	language = {en},
	number = {9},
	urldate = {2020-10-22},
	journal = {International Journal of Climatology},
	author = {D'Amato, N. and Lebel, T.},
	year = {1998},
	keywords = {Sahel, AMMA-CATCH, Hapex-Sahel, exponential distribution, interannual variability, mesoscale convective systems, rain events, storm rainfall},
	pages = {955--974},
}

@article{amani_relationship_1998,
	title = {Relationship between point rainfall, average sampled rainfall and ground truth at the event scale in the {Sahel}},
	volume = {12},
	issn = {0931-1955, 1435-151X},
	url = {http://link.springer.com/10.1007/s004770050014},
	doi = {10.1007/s004770050014},
	number = {2},
	urldate = {2020-10-22},
	journal = {Stochastic Hydrology and Hydraulics},
	author = {Amani, Abou and Lebel, T.},
	month = jul,
	year = {1998},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {141--154},
}

@article{lebel_space-time_1998,
	title = {A space-time rainfall disaggregation model adapted to {Sahelian} {Mesoscale} {Convective} {Complexes}},
	volume = {34},
	issn = {00431397},
	url = {http://doi.wiley.com/10.1029/98WR00434},
	doi = {10.1029/98WR00434},
	language = {en},
	number = {7},
	urldate = {2020-10-22},
	journal = {Water Resources Research},
	author = {Lebel, Thierry and Braud, Isabelle and Creutin, Jean-Dominique},
	month = jul,
	year = {1998},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {1711--1726},
}

@article{taylor_interactions_1997,
	title = {Interactions between the {Land} {Surface} and {Mesoscale} {Rainfall} {Variability} during {HAPEX}-{Sahel}},
	volume = {125},
	issn = {0027-0644},
	url = {https://journals-ametsoc-org.insu.bib.cnrs.fr/mwr/article/125/9/2211/104474/Interactions-between-the-Land-Surface-and},
	doi = {10.1175/1520-0493(1997)125<2211:IBTLSA>2.0.CO;2},
	language = {en},
	number = {9},
	urldate = {2020-10-22},
	journal = {Monthly Weather Review},
	author = {Taylor, Christopher M. and Saïd, Frédérique and Lebel, Thierry},
	month = sep,
	year = {1997},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {2211--2227},
}

@article{amani_lagrangian_1997,
	title = {Lagrangian kriging for the estimation of {Sahelian} rainfall at small time steps},
	volume = {192},
	issn = {00221694},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0022169496031046},
	doi = {10.1016/S0022-1694(96)03104-6},
	language = {en},
	number = {1-4},
	urldate = {2020-10-22},
	journal = {Journal of Hydrology},
	author = {Amani, A. and Lebel, T.},
	month = may,
	year = {1997},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {125--157},
}

@article{barbe_rainfall_1997,
	title = {Rainfall climatology of the {HAPEX}-{Sahel} region during the years 1950–1990},
	volume = {188-189},
	issn = {00221694},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S002216949603154X},
	doi = {10.1016/S0022-1694(96)03154-X},
	language = {en},
	urldate = {2020-10-22},
	journal = {Journal of Hydrology},
	author = {Barbé, L. Le and Lebel, T.},
	month = feb,
	year = {1997},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {43--73},
}

@article{lebel_rainfall_1997,
	title = {Rainfall monitoring during {HAPEX}-{Sahel}. 1. {General} rainfall conditions and climatology},
	volume = {188-189},
	issn = {00221694},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0022169496031551},
	doi = {10.1016/S0022-1694(96)03155-1},
	language = {en},
	urldate = {2020-10-22},
	journal = {Journal of Hydrology},
	author = {Lebel, T. and Taupin, J.D. and D'Amato, N.},
	month = feb,
	year = {1997},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {74--96},
}

@article{lebel_rainfall_1997-1,
	title = {Rainfall monitoring during {HAPEX}-{Sahel}. 2. {Point} and areal estimation at the event and seasonal scales},
	volume = {188-189},
	issn = {00221694},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0022169496033252},
	doi = {10.1016/S0022-1694(96)03325-2},
	language = {en},
	urldate = {2020-10-22},
	journal = {Journal of Hydrology},
	author = {Lebel, T. and Le Barbé, L.},
	month = feb,
	year = {1997},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {97--122},
}

@article{desconnets_hydrology_1997,
	title = {Hydrology of the {HAPEX}-{Sahel} {Central} {Super}-{Site}: surface water drainage and aquifer recharge through the pool systems},
	volume = {188-189},
	issn = {00221694},
	shorttitle = {Hydrology of the {HAPEX}-{Sahel} {Central} {Super}-{Site}},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0022169496031587},
	doi = {10.1016/S0022-1694(96)03158-7},
	language = {en},
	urldate = {2020-10-22},
	journal = {Journal of Hydrology},
	author = {Desconnets, J.C. and Taupin, J.D. and Lebel, T. and Leduc, C.},
	month = feb,
	year = {1997},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {155--178},
}

@article{vandervaere_estimating_1997,
	title = {Estimating hydraulic conductivity of crusted soils using disc infiltrometers and minitensiometers},
	volume = {188-189},
	issn = {00221694},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0022169496031605},
	doi = {10.1016/S0022-1694(96)03160-5},
	language = {en},
	urldate = {2020-10-22},
	journal = {Journal of Hydrology},
	author = {Vandervaere, J.-P. and Peugeot, C. and Vauclin, M. and Angulo Jaramillo, R. and Lebel, T.},
	month = feb,
	year = {1997},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {203--223},
}

@article{wai_variability_1997,
	title = {Variability in boundary layer structure during {HAPEX}-{Sahel} wet-dry season transition},
	volume = {188-189},
	issn = {00221694},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0022169496031794},
	doi = {10.1016/S0022-1694(96)03179-4},
	language = {en},
	urldate = {2020-10-22},
	journal = {Journal of Hydrology},
	author = {Wai, M.M.-K. and Smith, E.A. and Bessemoulin, P. and Culf, A.D. and Dolman, A.J. and Lebel, T.},
	month = feb,
	year = {1997},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {965--997},
}

@article{dherbes_land_1997,
	title = {Land surface conditions of the {Niamey} region: ecological and hydrological implications},
	volume = {188-189},
	issn = {00221694},
	shorttitle = {Land surface conditions of the {Niamey} region},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0022169496031538},
	doi = {10.1016/S0022-1694(96)03153-8},
	language = {en},
	urldate = {2020-10-22},
	journal = {Journal of Hydrology},
	author = {d'Herbès, J.M. and Valentin, C.},
	month = feb,
	year = {1997},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {18--42},
}

@article{leduc_water_1997,
	title = {Water table fluctuation and recharge in semi-arid climate: some results of the {HAPEX}-{Sahel} hydrodynamic survey ({Niger})},
	volume = {188-189},
	issn = {00221694},
	shorttitle = {Water table fluctuation and recharge in semi-arid climate},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0022169496031563},
	doi = {10.1016/S0022-1694(96)03156-3},
	language = {en},
	urldate = {2020-10-22},
	journal = {Journal of Hydrology},
	author = {Leduc, Christian and Bromley, John and Schroeter, Pierre},
	month = feb,
	year = {1997},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {123--138},
}

@article{bromley_estimation_1997,
	title = {Estimation of rainfall inputs and direct recharge to the deep unsaturated zone of southern {Niger} using the chloride profile method},
	volume = {188-189},
	issn = {00221694},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0022169496031575},
	doi = {10.1016/S0022-1694(96)03157-5},
	language = {en},
	urldate = {2020-10-22},
	journal = {Journal of Hydrology},
	author = {Bromley, J. and Edmunds, W.M. and Fellman, E. and Brouwer, J. and Gaze, S.R. and Sudlow, J. and Taupin, J.-D.},
	month = feb,
	year = {1997},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {139--154},
}

@article{brunel_use_1997,
	title = {Use of stable isotopes of water to determine the origin of water used by the vegetation and to partition evapotranspiration. {A} case study from {HAPEX}-{Sahel}},
	volume = {188-189},
	issn = {00221694},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0022169496031885},
	doi = {10.1016/S0022-1694(96)03188-5},
	language = {en},
	urldate = {2020-10-22},
	journal = {Journal of Hydrology},
	author = {Brunel, J.P. and Walker, G.R. and Dighton, J.C. and Monteny, B.},
	month = feb,
	year = {1997},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {466--481},
}

@article{moncrieff_spatial_1997,
	title = {Spatial and temporal variations in net carbon flux during {HAPEX}-{Sahel}},
	volume = {188-189},
	issn = {00221694},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0022169496031939},
	doi = {10.1016/S0022-1694(96)03193-9},
	language = {en},
	urldate = {2020-10-22},
	journal = {Journal of Hydrology},
	author = {Moncrieff, J.B. and Monteny, B. and Verhoef, A. and Friborg, Th. and Elbers, J. and Kabat, P. and de Bruin, H. and Soegaard, H. and Jarvis, P.G. and Taupin, J.D.},
	month = feb,
	year = {1997},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {563--588},
}

@article{troufleau_sensible_1997,
	title = {Sensible heat flux and radiometric surface temperature over sparse {Sahelian} vegetation. {I}. {An} experimental analysis of the {kB}−1 parameter},
	volume = {188-189},
	issn = {00221694},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0022169496031721},
	doi = {10.1016/S0022-1694(96)03172-1},
	language = {en},
	urldate = {2020-10-22},
	journal = {Journal of Hydrology},
	author = {Troufleau, D. and Lhomme, J.P. and Monteny, B. and Vidal, A.},
	month = feb,
	year = {1997},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {815--838},
}

@article{dolman_role_1997,
	title = {The role of the land surface in {Sahelian} climate: {HAPEX}-{Sahel} results and future research needs},
	volume = {188-189},
	issn = {00221694},
	shorttitle = {The role of the land surface in {Sahelian} climate},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0022169496031836},
	doi = {10.1016/S0022-1694(96)03183-6},
	language = {en},
	urldate = {2020-10-22},
	journal = {Journal of Hydrology},
	author = {Dolman, A.J. and Gash, J.H.C. and Goutorbe, J.-P. and Kerr, Y. and Lebel, T. and Prince, S.D. and Stricker, J.N.M.},
	month = feb,
	year = {1997},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {1067--1079},
}

@article{amani_typology_1996,
	title = {Typology of {Rainfall} {Fields} to {Improve} {Rainfall} {Estimation} in the {Sahel} by the {Area} {Threshold} {Method}},
	volume = {32},
	issn = {00431397},
	url = {http://doi.wiley.com/10.1029/96WR01100},
	doi = {10.1029/96WR01100},
	language = {en},
	number = {8},
	urldate = {2020-10-22},
	journal = {Water Resources Research},
	author = {Amani, Abou and Lebel, Thierry and Rousselle, Jean and Taupin, Jean Denis},
	month = aug,
	year = {1996},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {2473--2487},
}

@article{casse_potential_2015,
	title = {Potential of satellite rainfall products to predict {Niger} {River} flood events in {Niamey}},
	volume = {163},
	issn = {01698095},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0169809515000277},
	doi = {10.1016/j.atmosres.2015.01.010},
	language = {en},
	urldate = {2020-10-22},
	journal = {Atmospheric Research},
	author = {Casse, C. and Gosset, M. and Peugeot, C. and Pedinotti, V. and Boone, A. and Tanimoun, B.A. and Decharme, B.},
	month = sep,
	year = {2015},
	keywords = {AMMA-CATCH},
	pages = {162--176},
}

@article{vandervaere_prediction_1998,
	title = {Prediction of crust-induced surface runoff with disc infiltrometer data:},
	volume = {163},
	issn = {0038-075X},
	shorttitle = {Prediction of crust-induced surface runoff with disc infiltrometer data},
	url = {http://journals.lww.com/00010694-199801000-00003},
	doi = {10.1097/00010694-199801000-00003},
	language = {en},
	number = {1},
	urldate = {2020-10-22},
	journal = {Soil Science},
	author = {Vandervaere, Jean-Pierre and Vauclin, Michel and Haverkamp, Randel and Peugeot, Christophe and Thony, Jean-Louis and Gilfedder, Mathew},
	month = jan,
	year = {1998},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {9--21},
}

@article{cappelaere_recursive_2000,
	title = {A recursive algorithm for connectivity analysis in a grid; application to {2D} hydrodynamic modeling in heterogeneous soils},
	volume = {26},
	issn = {00983004},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0098300499000539},
	doi = {10.1016/S0098-3004(99)00053-9},
	language = {en},
	number = {2},
	urldate = {2020-10-22},
	journal = {Computers \& Geosciences},
	author = {Cappelaere, B. and Touma, J. and Peugeot, C.},
	month = mar,
	year = {2000},
	keywords = {AMMA-CATCH},
	pages = {121--135},
}

@article{brandt_changes_2019,
	title = {Changes in rainfall distribution promote woody foliage production in the {Sahel}},
	volume = {2},
	issn = {2399-3642},
	url = {http://www.nature.com/articles/s42003-019-0383-9},
	doi = {10.1038/s42003-019-0383-9},
	language = {en},
	number = {1},
	urldate = {2020-10-22},
	journal = {Communications Biology},
	author = {Brandt, Martin and Hiernaux, Pierre and Rasmussen, Kjeld and Tucker, Compton J. and Wigneron, Jean-Pierre and Diouf, Abdoul Aziz and Herrmann, Stefanie M. and Zhang, Wenmin and Kergoat, Laurent and Mbow, Cheikh and Abel, Christin and Auda, Yves and Fensholt, Rasmus},
	month = dec,
	year = {2019},
	keywords = {AMMA-CATCH, ext1},
	pages = {133},
}

@article{pierre_modeling_2014,
	title = {Modeling wind erosion flux and its seasonality from a cultivated sahelian surface: {A} case study in {Niger}},
	volume = {122},
	issn = {03418162},
	shorttitle = {Modeling wind erosion flux and its seasonality from a cultivated sahelian surface},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0341816214001702},
	doi = {10.1016/j.catena.2014.06.006},
	language = {en},
	urldate = {2020-10-22},
	journal = {CATENA},
	author = {Pierre, C. and Bergametti, G. and Marticorena, B. and AbdourhamaneTouré, A. and Rajot, J.-L. and Kergoat, L.},
	month = nov,
	year = {2014},
	keywords = {AMMA-CATCH},
	pages = {61--71},
}

@article{bateni_coupled_2014,
	title = {Coupled estimation of surface heat fluxes and vegetation dynamics from remotely sensed land surface temperature and fraction of photosynthetically active radiation},
	volume = {50},
	issn = {00431397},
	url = {http://doi.wiley.com/10.1002/2013WR014573},
	doi = {10.1002/2013WR014573},
	language = {en},
	number = {11},
	urldate = {2020-10-22},
	journal = {Water Resources Research},
	author = {Bateni, S. M. and Entekhabi, D. and Margulis, S. and Castelli, F. and Kergoat, L.},
	month = nov,
	year = {2014},
	keywords = {AMMA-CATCH},
	pages = {8420--8440},
}

@article{arnaud_automatic_1992,
	title = {Automatic {Tracking} and {Characterization} of {African} {Convective} {Systems} on {Meteosat} {Pictures}},
	volume = {31},
	issn = {0894-8763},
	url = {https://journals.ametsoc.org/jamc/article/31/5/443/14731/Automatic-Tracking-and-Characterization-of-African},
	doi = {10.1175/1520-0450(1992)031<0443:ATACOA>2.0.CO;2},
	language = {en},
	number = {5},
	urldate = {2020-10-22},
	journal = {Journal of Applied Meteorology},
	author = {Arnaud, Yves and Desbois, Michel and Maizi, Joel},
	month = may,
	year = {1992},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {443--453},
}

@article{braud_method_1994,
	title = {A {Method} for {Estimating} {Mean} {Areal} {Rainfall} {Using} {Moving} {Trend} {Functions} of the {Intensities}},
	volume = {33},
	issn = {0894-8763},
	url = {https://journals.ametsoc.org/jamc/article/33/12/1551/4192/A-Method-for-Estimating-Mean-Areal-Rainfall-Using},
	doi = {10.1175/1520-0450(1994)033<1551:AMFEMA>2.0.CO;2},
	language = {en},
	number = {12},
	urldate = {2020-10-22},
	journal = {Journal of Applied Meteorology},
	author = {Braud, Isabelle and Crochet, Philippe and Creutin, Jean-Dominique},
	month = dec,
	year = {1994},
	keywords = {AMMA-CATCH, EPSAT - Niger},
	pages = {1551--1561},
}

@article{abdou_babaye_characterization_2019,
	title = {Characterization of recharge mechanisms in a {Precambrian} basement aquifer in semi-arid south-west {Niger}},
	volume = {27},
	issn = {1431-2174, 1435-0157},
	url = {http://link.springer.com/10.1007/s10040-018-1799-x},
	doi = {10.1007/s10040-018-1799-x},
	language = {en},
	number = {2},
	urldate = {2020-10-22},
	journal = {Hydrogeology Journal},
	author = {Abdou Babaye, Maman Sani and Orban, Philippe and Ousmane, Boureima and Favreau, Guillaume and Brouyère, Serge and Dassargues, Alain},
	month = mar,
	year = {2019},
	keywords = {AMMA-CATCH},
	pages = {475--491},
}

@article{kendon_enhanced_2019,
	title = {Enhanced future changes in wet and dry extremes over {Africa} at convection-permitting scale},
	volume = {10},
	copyright = {2019 Crown},
	issn = {2041-1723},
	url = {https://www.nature.com/articles/s41467-019-09776-9},
	doi = {10.1038/s41467-019-09776-9},
	abstract = {African society is particularly vulnerable to climate change. The representation of convection in climate models has so far restricted our ability to accurately simulate African weather extremes, limiting climate change predictions. Here we show results from climate change experiments with a convection-permitting (4.5 km grid-spacing) model, for the first time over an Africa-wide domain (CP4A). The model realistically captures hourly rainfall characteristics, unlike coarser resolution models. CP4A shows greater future increases in extreme 3-hourly precipitation compared to a convection-parameterised 25 km model (R25). CP4A also shows future increases in dry spell length during the wet season over western and central Africa, weaker or not apparent in R25. These differences relate to the more realistic representation of convection in CP4A, and its response to increasing atmospheric moisture and stability. We conclude that, with the more accurate representation of convection, projected changes in both wet and dry extremes over Africa may be more severe.},
	language = {en},
	number = {1},
	urldate = {2021-03-04},
	journal = {Nature Communications},
	author = {Kendon, Elizabeth J. and Stratton, Rachel A. and Tucker, Simon and Marsham, John H. and Berthou, Ségolène and Rowell, David P. and Senior, Catherine A.},
	month = apr,
	year = {2019},
	keywords = {AMMA-CATCH, ext1, extérieur},
	pages = {1794},
}

@article{berthou_improved_2019,
	title = {Improved climatological precipitation characteristics over {West} {Africa} at convection-permitting scales},
	volume = {53},
	issn = {1432-0894},
	url = {https://doi.org/10.1007/s00382-019-04759-4},
	doi = {10.1007/s00382-019-04759-4},
	abstract = {The West African climate is unique and challenging to reproduce using standard resolution climate models as a large proportion of precipitation comes from organised deep convection. For the first time, a regional 4.5 km convection permitting simulation was performed on a pan-African domain for a period of 10 years (1997–2006). The 4.5 km simulation (CP4A) is compared with a 25 × 40 km convection-parameterised model (R25) over West Africa. CP4A shows increased mean precipitation, which results in improvements in the mature phase of the West African monsoon but deterioration in the early and late phases. The distribution of precipitation rates is improved due to more short lasting intense rainfall events linked with mesoscale convective systems. Consequently, the CP4A model shows a better representation of wet and dry spells both at the daily and sub-daily time-scales. The diurnal cycle of rainfall is improved, which impacts the diurnal cycle of monsoon winds and increases moisture convergence in the Sahel. Although shortcomings were identified, with implications for model development, this convection-permitting model provides a much more reliable precipitation distribution than its convection-parameterised counterpart at both daily and sub-daily time-scales. Convection-permitting scales will therefore be useful to address the crucial question of how the precipitation distribution will change in the future.},
	language = {en},
	number = {3},
	urldate = {2021-03-04},
	journal = {Climate Dynamics},
	author = {Berthou, Ségolène and Rowell, David P. and Kendon, Elizabeth J. and Roberts, Malcolm J. and Stratton, Rachel A. and Crook, Julia A. and Wilcox, Catherine},
	month = aug,
	year = {2019},
	keywords = {AMMA-CATCH, ext1},
	pages = {1991--2011},
}

@article{bichet_less_2018,
	title = {Less frequent and more intense rainfall along the coast of the {Gulf} of {Guinea} in {West} and {Central} {Africa} (1981-2014)},
	volume = {76},
	issn = {0936-577X, 1616-1572},
	url = {https://www.int-res.com/abstracts/cr/v76/n3/p191-201/},
	doi = {10.3354/cr01537},
	abstract = {Since the 1990s, rainfall has been reported to increase over the Gulf of Guinea. In light of the devastating floods that have occurred since the 1990s over the coastal areas of this region, this work aims to better characterize the recent trends in precipitation for this region. We used the Climate Hazards Group InfraRed Precipitation with Station (CHIRPS) product, a new observational rainfall dataset that covers the period 1981-2014 at high resolution and daily time steps. During the first rainy season (April-June), we find that the lack of significant trend observed in mean precipitation hides a trend towards less frequent but more intense rainfall along the coast of the Gulf of Guinea, which is expected to increase the likelihood of flooding and droughts, and fits with the recent increase in devastating floods. Over the north however (between 7° and 12.5°N), rainfall has become more frequent and less intense, which is expected to decrease the likelihood of flooding and droughts. During the second rainy season (September-November), we find that the clear increase in mean precipitation observed between 5° and 12.5°N results from an increase in precipitation intensity and frequency, while over southern Cameroon, the decrease in mean precipitation hides a trend towards less frequent but more intense rainfall. In both seasons, the average duration of wet spells has greatly decreased along the coast, in favor of more numerous and more intense isolated wet days.},
	language = {en},
	number = {3},
	urldate = {2021-03-04},
	journal = {Climate Research},
	author = {Bichet, Adeline and Diedhiou, Arona},
	month = oct,
	year = {2018},
	keywords = {AMMA-CATCH, ext1, CHIRPS, extérieur, AMMACATCH, Dry spell, Flood, Guinea Coast, Precipitation intensity, Trend, Wet spell},
	pages = {191--201},
}

@article{al_bitar_global_2017,
	title = {The global {SMOS} {Level} 3 daily soil moisture and brightness temperature maps},
	volume = {9},
	issn = {1866-3516},
	url = {https://essd.copernicus.org/articles/9/293/2017/},
	doi = {10.5194/essd-9-293-2017},
	abstract = {Abstract. The objective of this paper is to present the multi-orbit (MO) surface soil moisture (SM) and angle-binned brightness temperature (TB) products for the SMOS (Soil Moisture and Ocean Salinity) mission based on a new multi-orbit algorithm. The Level 3 algorithm at CATDS (Centre Aval de Traitement des Données SMOS) makes use of MO retrieval to enhance the robustness and quality of SM retrievals. The motivation of the approach is to make use of the longer temporal autocorrelation length of the vegetation optical depth (VOD) compared to the corresponding SM autocorrelation in order to enhance the retrievals when an acquisition occurs at the border of the swath. The retrieval algorithm is implemented in a unique operational processor delivering multiple parameters (e.g. SM and VOD) using multi-angular dual-polarisation TB from MO. A subsidiary angle-binned TB product is provided. In this study the Level 3 TB V310 product is showcased and compared to SMAP (Soil Moisture Active Passive) TB. The Level 3 SM V300 product is compared to the single-orbit (SO) retrievals from the Level 2 SM processor from ESA with aligned configuration. The advantages and drawbacks of the Level 3 SM product (L3SM) are discussed. The comparison is done on a global scale between the two datasets and on the local scale with respect to in situ data from AMMA-CATCH and USDA ARS Watershed networks. The results obtained from the global analysis show that the MO implementation enhances the number of retrievals: up to 9 \% over certain areas. The comparison with the in situ data shows that the increase in the number of retrievals does not come with a decrease in quality, but rather at the expense of an increased time lag in product availability from 6 h to 3.5 days, which can be a limiting factor for applications like flood forecast but reasonable for drought monitoring and climate change studies. The SMOS L3 soil moisture and L3 brightness temperature products are delivered using an open licence and free of charge using a web application (https://www.catds.fr/sipad/). The RE04 products, versions 300 and 310, used in this paper are also available at ftp://ext-catds-cpdc:catds2010@ftp.ifremer.fr/Land\_products/GRIDDED/L3SM/RE04/.},
	language = {en},
	number = {1},
	urldate = {2021-03-04},
	journal = {Earth System Science Data},
	author = {Al Bitar, Ahmad and Mialon, Arnaud and Kerr, Yann H. and Cabot, François and Richaume, Philippe and Jacquette, Elsa and Quesney, Arnaud and Mahmoodi, Ali and Tarot, Stéphane and Parrens, Marie and Al-Yaari, Amen and Pellarin, Thierry and Rodriguez-Fernandez, Nemesio and Wigneron, Jean-Pierre},
	month = jun,
	year = {2017},
	keywords = {AMMA-CATCH, ext1},
	pages = {293--315},
}

@article{pomeon_evaluating_2017,
	title = {Evaluating the performance of remotely sensed and reanalysed precipitation data over {West} {Africa} using {HBV} light},
	volume = {547},
	issn = {00221694},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0022169417300653},
	doi = {10.1016/j.jhydrol.2017.01.055},
	language = {en},
	urldate = {2021-07-01},
	journal = {Journal of Hydrology},
	author = {Poméon, Thomas and Jackisch, Dominik and Diekkrüger, Bernd},
	month = apr,
	year = {2017},
	keywords = {AMMA-CATCH, ext1, extérieur},
	pages = {222--235},
}

@article{martin-rosales_dynamiques_2003,
	title = {Dynamiques de vidange d'une mare temporaire au {Sahel} : l'exemple de {Banizoumbou} ({Sud}-{Ouest} du {Niger})},
	volume = {335},
	issn = {16310713},
	shorttitle = {Dynamiques de vidange d'une mare temporaire au {Sahel}},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S1631071303000592},
	doi = {10.1016/S1631-0713(03)00059-2},
	language = {fr},
	number = {5},
	urldate = {2021-08-26},
	journal = {Comptes Rendus Geoscience},
	author = {Martin-Rosales, Wenceslas and Leduc, Christian},
	month = may,
	year = {2003},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {461--468},
}

@article{favreau_depression_2002,
	title = {Une dépression piézométrique naturelle en hausse au {Sahel} ({Sud}-{Ouest} du {Niger})},
	volume = {334},
	issn = {16310713},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S1631071302017637},
	doi = {10.1016/S1631-0713(02)01763-7},
	language = {fr},
	number = {6},
	urldate = {2021-08-27},
	journal = {Comptes Rendus Geoscience},
	author = {Favreau, Guillaume and Leduc, Christian and Marlin, Christelle and Guéro, Abdou},
	month = jan,
	year = {2002},
	keywords = {AMMA-CATCH},
	pages = {395--401},
}

@article{leduc_recharge_1996,
	title = {Recharge of the {Continental} {Terminal} water-table ({Niamey}, {Niger}) estimated from tritium measurements and modelling},
	volume = {323},
	language = {fr},
	number = {7},
	journal = {Comptes Rendus De l'Academie Des Sciences Serie II a - Sciences},
	author = {Leduc, C. and Taupin, J-D. and LaSalle, CL.},
	year = {1996},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {599--605},
}

@article{leduc_comparison_2000,
	title = {Comparison of recharge estimates for the two largest aquifers in {Niger}, based on hydrodynamic and isotopic data},
	volume = {262},
	issn = {0144-7815},
	journal = {IAHS Publ.},
	author = {Leduc, C. and Favreau, G. and Marlin, C. and Dray, M.},
	year = {2000},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {391--399},
}

@article{favreau_groundwater_2001,
	title = {Groundwater recharge increase induced by land-use change: comparison of hydrodynamic and isotopic estimates in semiarid {Niger}},
	volume = {269},
	journal = {IAHS Publ.},
	author = {Favreau, G. and Leduc, C. and Marlin, C.},
	year = {2001},
	keywords = {AMMA-CATCH},
	pages = {67--74},
}

@article{robert_environmental_2021,
	title = {Environmental determinants of {E}. coli, link with the diarrheal diseases, and indication of vulnerability criteria in tropical {West} {Africa} ({Kapore}, {Burkina} {Faso})},
	volume = {15},
	issn = {1935-2735},
	url = {https://dx.plos.org/10.1371/journal.pntd.0009634},
	doi = {10.1371/journal.pntd.0009634},
	abstract = {In 2017, diarrheal diseases were responsible for 606 024 deaths in Sub-Saharan Africa. This situation is due to domestic and recreational use of polluted surface waters, deficits in hygiene, access to healthcare and drinking water, and to weak environmental and health monitoring infrastructures. Escherichia coli ( E . coli ) is an indicator for the enteric pathogens that cause many diarrheal diseases. The links between E . coli , diarrheal diseases and environmental parameters have not received much attention in West Africa, and few studies have assessed health risks by taking into account hazards and socio-health vulnerabilities. This case study, carried out in Burkina Faso (Bagre Reservoir), aims at filling this knowledge gap by analyzing the environmental variables that play a role in the dynamics of E . coli , cases of diarrhea, and by identifying initial vulnerability criteria. A particular focus is given to satellite-derived parameters to assess whether remote sensing can provide a useful tool to assess the health hazard. Samples of surface water were routinely collected to measure E . coli , enterococci and suspended particulate matter (SPM) at a monitoring point (Kapore) during one year. In addition, satellite data were used to estimate precipitation, water level, Normalized Difference Vegetation Index (NDVI) and SPM. Monthly epidemiological data for cases of diarrhea from three health centers were also collected and compared with microbiological and environmental data. Finally, semi-structured interviews were carried out to document the use of water resources, contact with elements of the hydrographic network, health behavior and condition, and water and health policy and prevention, in order to identify the initial vulnerability criteria. A positive correlation between E . coli and enterococci in surface waters was found indicating that E . coli is an acceptable indicator of fecal contamination in this region. E . coli and diarrheal diseases were strongly correlated with monsoonal precipitation, in situ SPM, and Near Infra-Red (NIR) band between March and November. Partial least squares regression showed that E . coli concentration was strongly associated with precipitation, Sentinel-2 reflectance in the NIR and SPM, and that the cases of diarrhea were strongly associated with precipitation, NIR, E . coli , SPM, and to a lesser extent with NDVI. Moreover, E . coli dynamics were reproduced using satellite data alone, particularly from February to mid-December (R 2 = 0.60) as were cases of diarrhea throughout the year (R 2 = 0.76). This implies that satellite data could provide an important contribution to water quality monitoring. Finally, the vulnerability of the population was found to increase during the rainy season due to reduced accessibility to healthcare and drinking water sources and increased use of water of poor quality. During this period, surface water is used because it is close to habitations, easy to use and free from monetary or political constraints. This vulnerability is aggravated by marginality and particularly affects the Fulani, whose concessions are often close to surface water (river, lake) and far from health centers.},
	language = {en},
	number = {8},
	urldate = {2022-01-10},
	journal = {PLOS Neglected Tropical Diseases},
	author = {Robert, Elodie and Grippa, Manuela and Nikiema, Dayangnéwendé Edwige and Kergoat, Laurent and Koudougou, Hamidou and Auda, Yves and Rochelle-Newall, Emma},
	editor = {Bourret, Travis J.},
	month = aug,
	year = {2021},
	keywords = {AMMA-CATCH},
	pages = {e0009634},
}

@article{hiernaux_woody_2022,
	title = {Woody plant decline in the {Sahel} of western {Niger} (1996-2017):is it driven by climate or land use changes?},
	volume = {200},
	issn = {0140-1963},
	shorttitle = {Woody plant decline in the {Sahel} of western {Niger} (1996–2017)},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0140196322000143},
	doi = {10.1016/j.jaridenv.2022.104719},
	abstract = {Although a recovery of woody vegetation has been observed throughout the Sahel, western Niger has not followed the overall satellite-derived greening trend. While satellite imagery can be used to study overall patterns and trends, only field observations can provide insights in the dynamics of woody plant populations. Here we used field data from 29 sites in the Dantiandou district in Niger to study woody species composition, plant density, crown cover, basal area, foliage and wood mass from 1996 to 2017. All sites show a decrease in woody plant parameters with a faster decrease in rangeland than in agricultural land. Most of the decrease is due to the loss of shrubs, while trees do not change significantly. When field observations were scaled up to the district level using land use maps, shrub density decreased from 342 to 155 ha-1 in agricultural land, and from 1567 to 250 ha-1 in rangeland. Trends in annual rainfall and soil moisture during the study period were not significant and cannot explain the decrease of woody vegetation. Instead, the expansion of cropped areas, shortened crop-fallow cycles and increasing pressure on wood resources to satisfy demand for fuel and construction materials may have contributed to the decline.},
	language = {en},
	journal = {Journal of Arid Environments},
	author = {Hiernaux, P and Kalilou, AA and Kergoat, L and Brandt, M and Mougin, E and Fitts, Y},
	month = may,
	year = {2022},
	keywords = {AMMA-CATCH},
	pages = {104719},
}

@article{bergametti_rain_2022,
	title = {Rain, {Wind}, and {Dust} {Connections} in the {Sahel}},
	volume = {127},
	issn = {2169-897X},
	doi = {10.1029/2021JD035802},
	abstract = {The Sahel is a dust source region where dust emission could be drastically modified in the future due to climatic and land use changes. Based on observations of meteorological parameters and dust concentration for about 1,000 rain events, we investigated the processes leading to dust emission during the rainy season when Mesoscale Convective Systems (MCSs) regularly cross the Sahel. We show that the highest wind speed is strongly linked to the MCS cold pool intensity, which is characterized by a drop in surface temperature. This is observed during the premonsoon period (similar to May to June) when the midtroposphere is still sufficiently dry to allow intense evaporation of raindrops. Because this coincides with the time of the year that the surface is the least protected by the vegetative residue, the premonsoon wind speed leads to the highest observed dust concentration in our record. Most of the highest wind speed occur before or just at the beginning of a rainy event allowing a large part of the dust raised to be transported ahead the rain limiting dust removal by wet scavenging. Finally, we show that the number of 5-min dust concentration higher than 5,000 mu g m(-3) is almost only occurring during the rainy season. These results suggest that until the dust models fail to correctly resolve MCS, it will be difficulty to obtain reliable estimates of dust emission from the Sahel for the present or future scenarios.},
	number = {3},
	journal = {JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES},
	author = {Bergametti, G and Rajot, JL and Marticorena, B and Feron, A and Gaimoz, C and Chatenet, B and Coulibaly, M and Kone, I and Maman, A and Zakou, A},
	month = feb,
	year = {2022},
}

@article{gobron_evaluation_2022,
	title = {Evaluation of {Sentinel}-{3A} and {Sentinel}-{3B} ocean land colour instrument green instantaneous fraction of absorbed photosynthetically active radiation},
	volume = {270},
	issn = {0034-4257},
	doi = {10.1016/j.rse.2021.112850},
	abstract = {This article presents the evaluation of the Copernicus Sentinel-3 Ocean Land Colour Instrument (OLCI) operational terrestrial products corresponding to the green instantaneous Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) and its associated rectified channels. These products are estimated using OLCI spectral measurements acquired at the top of the atmosphere by a physically-based approach and are available operationally at full (300 m) and reduced (1.2 km) spatial resolution daily. The evaluation of the quality of the FAPAR OLCI values was based on the availability of data acquired over several years by Sentinel-3A (S3A) and Sentinel 3B (S3B). The evaluation exercise consisted of several stages: first, an overall comparison of the two S3 platform products was carried out during the tandem phase; second, comparison with an FAPAR climatology derived from the Medium Resolution Imaging Spectrometer (MERIS) provided information on the seasonality of various types of land cover. Then, direct comparisons were made with the same type of FAPAR products retrieved from two sensors, the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Sentinel-2 (S2) Multispectral Instrument (MSI), and with several ground-based estimates. In addition, an analysis of the efficiency of the retrieval algorithm with 3D radiative transfer simulations was performed. The results indicated that the consistency between daily and monthly S3A and S3B on a global scale was very good during the tandem phase (RMSD = 0.01 and a correlation R-2 of 0.99 with a bias of 0.003); we found an agreement with a correlation of 0.95 and 0.93 (RMSD = 0.07 and 0.09) with JRC FAPAR S2 and JRC FAPAR MODIS, respectively. Compatibility with the ground-based data was between 0.056 and 0.24 in term of RMSD depending on the type of vegetation with an overall R-2 of 0.89. Immler diagrams demonstrate that their variances were lower than the total uncertainties. The quality assurance using 3D radiative transfer model has shown that the apparent performance of the algorithm depends strongly on the type of in-situ measurement and canopy type.},
	journal = {REMOTE SENSING OF ENVIRONMENT},
	author = {Gobron, N and Morgan, O and Adams, J and Brown, LA and Cappucci, F and Dash, J and Lanconelli, C and Marioni, M and Robustelli, M},
	month = mar,
	year = {2022},
}

@article{gangneron_persistence_2022,
	title = {Persistence and success of the {Sahel} desertification narrative},
	volume = {22},
	issn = {1436-378X},
	url = {https://doi.org/10.1007/s10113-022-01969-1},
	doi = {10.1007/s10113-022-01969-1},
	abstract = {The paradigm of Sahelian desertification, whose roots lie in the colonial period, increased in popularity following the droughts of the 1970s and 1980s. This “desertification narrative” was shaped in the international arena by organizations working in the fields of international cooperation, human rights, regional development, economic regulation and environmental questions. This narrative has been deployed to have real-world implications of how risks and responses in the Sahel are understood and prioritised, with particularly tangible implications for civil society and international donor agencies. It is indeed widely used in technical writings, general public media and environmental protection projects, regardless of the fact that the majority of literature in environmental science does not support its underlying rationales. It depicts rural populations as victims and culprits (or villains) partially responsible for the desertification, which in turn justifies external intervention in the Sahelian countries. The desertification narrative has an impact on research and development funding by overemphasizing the role of international development aid to combat desertification, thus favoring research on the subject of Sahelian desertification. Furthermore, we argue that the Sahelian desertification narrative contributes to the political control of rural populations, the latter being stigmatized because of their often-considered excessive use of environmental resources.},
	number = {4},
	journal = {Regional Environmental Change},
	author = {Gangneron, Fabrice and Pierre, Caroline and Robert, Elodie and Kergoat, Laurent and Grippa, Manuela and Guichard, Françoise and Hiernaux, Pierre and Leauthaud, Crystele},
	month = sep,
	year = {2022},
	pages = {118},
}

@article{miller_modelling-chain_2022,
	title = {A modelling-chain linking climate science and decision-makers for future urban flood management in {West} {Africa}},
	volume = {22},
	issn = {1436-3798},
	url = {https://link.springer.com/10.1007/s10113-022-01943-x},
	doi = {10.1007/s10113-022-01943-x},
	abstract = {Intensification of the hydrological cycle resulting from climate change in West Africa poses significant risks for the region's rapidly urbanising cities, but limited research on flood risk has been undertaken at the urban domain scale. Furthermore, conventional climate models are unable to realistically represent the type of intense storms which dominate the West African monsoon. This paper presents a decision-first framing of climate research in co-production of a climate-hydrology-flooding modelling chain, linking scientists working on state-of-the-art regional climate science with decision-makers involved in city planning for future urban flood management in the city of Ouagadougou, Burkina Faso. The realistic convection-permitting model over Africa (CP4A) is applied at the urban scale for the first time and data suggest significant intensification of high-impact weather events and demonstrate the importance of considering the spatio-temporal scales in CP4A. Hydrological modelling and hydraulic modelling indicate increases in peak flows and flood extents in Ouagadougou in response to climate change which will be further exacerbated by future urbanisation. Advances in decision-makers' capability for using climate information within Ouagadougou were observed, and key recommendations applicable to other regional urban areas are made. This study provides proof of concept that a decision-first modelling-chain provides a methodology for co-producing climate information that can, to some extent, bridge the usability gap between what scientists think is useful and what decision-makers need.},
	language = {en},
	number = {3},
	journal = {Regional Environmental Change},
	author = {Miller, JD and Vischel, T and Fowe, T and Panthou, G and Wilcox, C and Taylor, CM and Visman, E and Coulibaly, G and Gonzalez, P and Body, R and Vesuviano, G and Bouvier, C and Chahinian, N and Cazenave, F},
	month = sep,
	year = {2022},
	keywords = {AMMA-CATCH, AMMA2050},
	pages = {93},
}

@article{miller_high-impact_2022,
	title = {High-impact weather and urban flooding in the {West} {African} {Sahel}-{A} multidisciplinary case study of the 2009 event in {Ouagadougou}},
	volume = {36},
	issn = {2212-0947},
	doi = {10.1016/j.wace.2022.100462},
	abstract = {On September 1st 2009 an extreme high-impact weather event occurred in Burkina Faso that had significant impacts upon the capital city Ouagadougou and its inhabitants. Subsequent reporting and research has however not focused on the contributing socio-economic and hydrological factors and the role of global warming and climatic change remains uncertain. This reflects a paucity of evidence attributing such extreme weather events to climate change for the West Africa region and limits the knowledge base for urban planning to climate-related risks which pose serious threats. This case study provides a holistic assessment of the most extreme urban hydrometeorological event recorded in the West African Sahel, that links synoptic conditions to climate change and through to hydrological impacts on vulnerable urban populations. The intention is to inform regional decisionmakers on climate change and flood-generating high-impact weather events at the urban scale and to bridge the gap between what scientists understand as useful and decision-makers view as useable at the city scale by providing interdisciplinary answers to key questions raised by local stakeholders. Such an approach was shown to foster enhanced dialogue and engagement with stakeholders, while also providing a focus for communicating science at variable time- and spatial scales and between disciplines to improve understanding of how global processes have localised consequences. This reveals that Ouagadougou remains vulnerable to climate change and that such extreme weather events will become more frequent. But it is also demonstrated the complexity of attributing extreme events at such localised 'urban' scales to atmospheric phenomena affected by global climate change. Regional climate models are evolving and becoming more able to represent such extreme weather phenomena at suitable scales, enabling improved representation of climatedriven changes on such events, improving the ability for short-range forecasts in the future. Frameworks for managing flood risks however remain weak and under-resourced and there is limited capacity to manage flood risk from such events, particularly when rapid urbanisation amplifies vulnerability concerns. Recommendations are made to improve flood-resilience to future storms.},
	journal = {WEATHER AND CLIMATE EXTREMES},
	author = {Miller, J and Taylor, C and Guichard, F and Peyrill, P and Vischel, T and Fowe, T and Panthou, G and Visman, E and Bologo, M and Traore, K and Coulibaly, G and Chapelon, N and Beucher, F and Rowell, DP and Parker, DJ},
	month = jun,
	year = {2022},
}

@article{pellarin_smos_2022,
	title = {From {SMOS} {Soil} {Moisture} to 3-hour {Precipitation} {Estimates} at 0.1 degrees {Resolution} in {Africa}},
	volume = {14},
	issn = {2072-4292},
	doi = {10.3390/rs14030746},
	abstract = {Several recent studies have shown that knowledge of the spatiotemporal dynamics of soil moisture intrinsically contains information on precipitation. In this study, we show how SMOS measurements can be used to generate a near-real-time precipitation product with a spatial resolution of 0.1 degrees and a temporal resolution of 3 h. The principle consists of assimilating the SMOS data into a model that simulates the evolution of soil moisture, which is forced by a satellite precipitation product. The assimilation of SMOS soil moisture leads to an adjustment of the satellite precipitation rates. Using data from more than 200 rain gauges set up in Africa between 2010 and 2021, we show that the PrISM algorithm (for Precipitation Inferred from Soil Moisture) almost systematically improves the initial precipitation product. One of the original features of this study is that we used the IMERG-Early satellite precipitation product, which has a finer spatial resolution (0.1 degrees) than SMOS ({\textasciitilde}0.25 degrees). Despite this, the methodology reduces both the RMSE and bias of IMERG-Early. The RMSE is reduced from 8.0 to 6.3 mm/day, and the absolute bias is reduced from 0.81 to 0.63 mm/day on average over the 200 rain gauges. PrISM performs even slightly better on average than IMERG-Final in terms of RMSE (6.8 mm/day for IMERG-Final) but better scores are obtained by IMERG-Final in terms of absolute bias (0.35 mm/day), which utilizes a network of field measurements to correct the biases of the IMERG-Early product with a 2.5-month delay. Therefore, the use of SMOS soil moisture measurements for Africa can be an advantageous alternative to the use of gauge measurements for debiasing rainfall satellite products in real time.},
	number = {3},
	journal = {REMOTE SENSING},
	author = {Pellarin, T and Zoppis, A and Roman-Cascon, C and Kerr, YH and Rodriguez-Fernandez, N and Panthou, G and Philippon, N and Cohard, JM},
	month = feb,
	year = {2022},
}

@article{allies_remote_2022,
	title = {A remote sensing data fusion method for continuous daily evapotranspiration mapping at kilometric scale in {Sahelian} areas},
	volume = {607},
	issn = {0022-1694},
	doi = {10.1016/j.jhydrol.2022.127504},
	abstract = {Thermal infrared (TIR) remote sensing-based ET estimates are very appealing for a wide range of scientific applications in hydrology. However, they are prone to infrequency due to satellite revisit interval and cloud cover. Temporal interpolation techniques or multi-resolution and multi-frequency data fusion approach have thus recently been studied to provide continuous ET estimates. It has been already shown that the interest of temporal interpolation techniques is limited to short return interval that is troublesome in Sahelian regions where mesoscale convective systems linked to the West African Monsoon (WAM) renders unusable most of TIR images during the rainy season. Here we developed a data fusion approach to provide remote sensing-based continuous daily ET estimates at kilometric resolution in Sahelian areas. The proposed algorithm fill gaps in MODIS-based ET estimates from EVASPA S-SEBI Sahel (E3S) using the Global Land Evaporation: the Amsterdam Methodology (GLEAM) product and/or ET estimates from a simple parametric model for typical Sahelian ecosystems as a normalized basis. The fusion algorithm is evaluated at the pixel scale against eddy-covariance measurements and simulations of a locally calibrated and validated land surface model (LSM) on a millet crop and a fallow of shrubby savannah in the southwest of the Republic of Niger. Consistency of the fusion approach is also evaluated at mesoscale by comparing it with a set of 20 regional LSMs. Globally both level of comparison highlight the very good agreement of ET estimates based on the fusion approach with both in situ measurements and LSMs simulations. We also show the benefit of such a fusion approach compared to linear temporal interpolation techniques of the ratio between ET and either incoming solar radiation or reference evapotranspiration. The main benefits are observed during the first months of the rainy season in the depiction of the surface response to rainfall events and consecutive drying up of the surface soil layer. We suggest that such a fusion approach could be later used in disaggregation chain to enhance field scaled ET estimates by the combination of coarse, moderate and high resolution remote sensing-based ET estimates.},
	journal = {JOURNAL OF HYDROLOGY},
	author = {Allies, A and Olioso, A and Cappelaere, B and Boulet, G and Etchanchu, J and Barral, H and Moussa, IB and Chazarin, JP and Delogu, E and Issoufou, HBA and Mainassara, I and Oi, M and Demarty, J},
	month = apr,
	year = {2022},
}

@article{dorigo_international_2021,
	title = {The {International} {Soil} {Moisture} {Network}: serving  {Earth} system science for over a decade},
	volume = {25},
	issn = {1607-7938},
	url = {https://hess.copernicus.org/articles/25/5749/2021/},
	doi = {10.5194/hess-25-5749-2021},
	number = {11},
	journal = {Hydrol. Earth Syst. Sci.},
	author = {Dorigo, W. and Himmelbauer, I. and Aberer, D. and Schremmer, L. and Petrakovic, I. and Zappa, L. and Preimesberger, W. and Xaver, A. and Annor, F. and Ardö, J. and Baldocchi, D. and Bitelli, M. and Blöschl, G. and Bogena, H. and Brocca, L. and Calvet, J.-C. and Camarero, J. J. and Capello, G. and Choi, M. and Cosh, M. C. and van de Giesen, N. and Hajdu, I. and Ikonen, J. and Jensen, K. H. and Kanniah, K. D. and de Kat, I. and Kirchengast, G. and Kumar Rai, P. and Kyrouac, J. and Larson, K. and Liu, S. and Loew, A. and Moghaddam, M. and Martínez Fernández, J. and Mattar Bader, C. and Morbidelli, R. and Musial, J. P. and Osenga, E. and Palecki, M. A. and Pellarin, T. and Petropoulos, G. P. and Pfeil, I. and Powers, J. and Robock, A. and Rüdiger, C. and Rummel, U. and Strobel, M. and Su, Z. and Sullivan, R. and Tagesson, T. and Varlagin, A. and Vreugdenhil, M. and Walker, J. and Wen, J. and Wenger, F. and Wigneron, J. P. and Woods, M. and Yang, K. and Zeng, Y. and Zhang, X. and Zreda, M. and Dietrich, S. and Gruber, A. and van Oevelen, P. and Wagner, W. and Scipal, K. and Drusch, M. and Sabia, R.},
	month = nov,
	year = {2021},
	note = {Publisher: Copernicus Publications},
	pages = {5749--5804},
}

@article{brocca_river_2020,
	title = {River flow prediction in data scarce regions: soil moisture integrated satellite rainfall products outperform rain gauge observations in {West} {Africa}},
	volume = {10},
	issn = {2045-2322},
	shorttitle = {River flow prediction in data scarce regions},
	url = {http://www.nature.com/articles/s41598-020-69343-x},
	doi = {10.1038/s41598-020-69343-x},
	abstract = {Satellite precipitation products have been largely improved in the recent years particularly with the launch of the global precipitation measurement (GPM) core satellite. Moreover, the development of techniques for exploiting the information provided by satellite soil moisture to complement/enhance precipitation products have improved the accuracy of accumulated rainfall estimates over land. Such satellite enhanced precipitation products, available with a short latency ({\textless} 1 day), represent an important and new source of information for river flow prediction and water resources management, particularly in developing countries in which ground observations are scarcely available and the access to such data is not always ensured. In this study, three recently developed rainfall products obtained from the integration of GPM rainfall and satellite soil moisture products have been used; namely GPM+SM2RAIN, PRISM-SMOS, and PRISM-SMAP. The prediction of observed daily river discharge at 10 basins located in Europe (4), West Africa (3) and South Africa (3) is carried out. For comparison, we have also considered three rainfall products based on: (1) GPM only, i.e., the Early Run version of the Integrated Multi-Satellite Retrievals for GPM (GPM-ER), (2) rain gauges, i.e., the Global Precipitation Climatology Centre, and (3) the latest European Centre for Medium-Range Weather Forecasts reanalysis, ERA5. Three different conceptual and lumped rainfall-runoff models are employed to obtain robust and reliable results over the 3-year data period 2015–2017. Results indicate that, particularly over scarcely gauged areas (West Africa), the integrated products outperform both ground- and reanalysis-based rainfall estimates. For all basins, the GPM+SM2RAIN product is performing the best among the short latency products with mean Kling–Gupta Efficiency (KGE) equal to 0.87, and significantly better than GPM-ER (mean KGE = 0.77). The integrated products are found to reproduce particularly well the high flows. These results highlight the strong need to disseminate such integrated satellite rainfall products for hydrological (and agricultural) applications in poorly gauged areas such as Africa and South America.},
	language = {en},
	number = {1},
	journal = {Scientific Reports},
	author = {Brocca, Luca and Massari, Christian and Pellarin, Thierry and Filippucci, Paolo and Ciabatta, Luca and Camici, Stefania and Kerr, Yann H. and Fernández-Prieto, Diego},
	month = jul,
	year = {2020},
	keywords = {AMMA-CATCH, Benin, Oueme},
	pages = {12517},
}

@article{favreau_land_2009,
	title = {Land clearing, climate variability, and water resources increase in semiarid southwest {Niger}: a review},
	volume = {45},
	issn = {0043-1397},
	shorttitle = {Land clearing, climate variability, and water resources increase in semiarid southwest {Niger}},
	url = {10.1029/2007WR006785},
	doi = {10.1029/2007WR006785},
	number = {7},
	journal = {Water Resources Research},
	author = {Favreau, G. and Cappelaere, B. and Massuel, S. and Leblanc, M. and Boucher, M. and Boulain, N. and Leduc, C.},
	year = {2009},
	keywords = {AMMA-CATCH, Niger, Rainfall variability, HYBIS, aquifer characterization, burkina-faso, endoreic catchment, Groundwater recharge, hydrologic process simulation, long-term rise, paleoclimate reconstruction, precipitation chemistry, sahelian west niger},
	pages = {W00A16},
}

@article{seghieri_relationships_2009,
	title = {Relationships between climate, soil moisture and phenology of the woody cover in two sites located along the {West} {African} latitudinal gradient},
	volume = {375},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/B6V6C-4VGF41K-3/2/1d409178e500d0c5a9e3227d30487574},
	doi = {10.1016/j.jhydrol.2009.01.023},
	abstract = {The study quantifies the relationships at local scale between phenology and determinants of climate and soil water resources at two sites located along the latitudinal gradient of West Africa, one in the central Sahel (Mali), the other in the Sudanian bioclimatic zone (Benin). The aim is to improve our knowledge on possible vegetation response to possible climate change. Within the Sudanian site, average annual rainfall is 1200 mm, extending from April to October, while, in the Sahelian site, it is 370 mm, occurring from June to September. Physical data were collected from the African Monsoon Multidisciplinary Analysis research programme. The phenology of the dominant species was monitored in four types of vegetation cover at the wetter site, and in three types of vegetation cover at the drier site. For each sampled plant, leafing, flowering and fruiting were recorded as binary variables in terms of the presence/absence of phenophases. A small proportion of the variability of each phenophase occurrence is explained by the logit models. However, rainfall rise is significantly linked to leafing probability increase in the Sahelian site but not in the Sudanian site. Day length extension and temperature decrease are significantly correlated with an increase in leafing in the Sudanian site, but not in the Sahelian. On both sites, the increase in cumulative rainfall is not found to be linked to an increased probability of reproductive phenophases (negative or non-significant relationships). Air temperature is positively correlated with flowering rate in the Sudanian site, but, all other factors being constant, no climate factors are found to be highly significant of flowering occurrence in the Sahel. Fruiting probability is positively correlated mainly with temperature within the Sahelian site. Leafing occurrence is positively correlated with soil moisture in the 0-1 m layer for the Sudanian site, but not for the Sahelian site. Significant relationships between fruiting occurrence and soil moisture may reflect a prior selection of plants on fruiting period that maximizes seed dispersion and germination differently at the two sites. While vegetative and reproduction schedules may be determined by specific genetic factors, the physical environment controls the possibility of their expression. Reduction of the rainfall amount and intensity may increase reproduction rates in wet areas. Although this factor should decrease leafing rate, it does not influence reproduction at dry sites, except through the decrease in air humidity. In wetter areas, increasing temperature may reduce leafing, but may increase reproduction rates. Cover reduction may have an impact on local physical factors and, consequently, probably also affects vegetation phenology.},
	number = {1-2},
	urldate = {2011-04-08},
	journal = {Journal of Hydrology},
	author = {Seghieri, Josiane and Vescovo, Aude and Padel, Karine and Soubie, Remy and Arjounin, Marc and Boulain, Nicolas and de Rosnay, Patricia and Galle, Sylvie and Gosset, Marielle and Mouctar, Abakar H. and Peugeot, Christophe and Timouk, Franck},
	month = aug,
	year = {2009},
	keywords = {Sudanian climate, Sahel, AMMA-CATCH, Benin, Mali, HYBIS, Determining factors, Life cycle, Logit model, Stand},
	pages = {78--89},
}

@article{peugeot_mesoscale_2011,
	title = {Mesoscale water cycle within the {West} {African} {Monsoon}},
	volume = {12},
	issn = {1530-261X},
	url = {http://doi.wiley.com/10.1002/asl.309},
	doi = {10.1002/asl.309},
	number = {1},
	urldate = {2011-04-08},
	journal = {Atmospheric Science Letters},
	author = {Peugeot, C. and Guichard, F. and Bock, O. and Bouniol, D. and Chong, M. and Boone, A. and Cappelaere, B. and Gosset, M. and Besson, L. and Lemaître, Y. and Séguis, L. and Zannou, A. and Galle, S. and Redelsperger, J-L.},
	month = jan,
	year = {2011},
	keywords = {AMMA-CATCH, HYBIS},
	pages = {45--50},
}

@article{nazoumou_petite_2016,
	title = {La petite irrigation par les eaux souterraines, une solution durable contre la pauvreté et les crises alimentaires au {Niger} ?},
	volume = {25},
	issn = {1166-7699, 1777-5949},
	url = {http://www.cahiersagricultures.fr/10.1051/cagri/2016005},
	doi = {10.1051/cagri/2016005},
	number = {1},
	urldate = {2016-05-19},
	journal = {Cahiers Agricultures},
	author = {Nazoumou, Yahaya and Favreau, Guillaume and Adamou, Mahaman Moustapha and Maïnassara, Ibrahim},
	month = jan,
	year = {2016},
	keywords = {AMMA-CATCH, niger},
	pages = {15003},
}

@article{massuel_integrated_2011,
	title = {Integrated surface water–groundwater modelling in the context of increasing water reserves of a regional {Sahelian} aquifer},
	volume = {56},
	issn = {0262-6667},
	url = {http://www.tandfonline.com/doi/abs/10.1080/02626667.2011.609171},
	doi = {10.1080/02626667.2011.609171},
	abstract = {Abstract Despite the Sahelian drought of the 1970s–1990s, the unconfined aquifer in southwest Niger exhibits a multidecadal increase in groundwater reserves. Recent changes in land surface conditions have enhanced runoff and thus indirect groundwater recharge below endorheic ponds. This paper presents a model-based investigation of surface runoff and groundwater recharge at mesoscale (∼5000 km2). A new lumped-conceptual runoff model applicable to the large number of ungauged endorheic catchments is specially developed, derived from an existing fine-scale, physically-based hydrologic model. Runoff simulated for sites identified as groundwater recharge sources are used to derive recharge forcing for a Modflow-based model of the aquifer. The rising water table trend and its spatial distribution over the period 1992–2003 are generally well simulated, albeit smoothed year-to-year dynamics. Comparison with alternative methods of recharge estimation suggests, however, that there may presently exist more recharging sites and/or contributing surfaces than those considered so far. Citation Massuel, S., Cappelaere, B., Favreau, G., Leduc, C., Lebel, T. \& Vischel, T. (2011) Integrated surface water–groundwater modelling in the context of increasing water reserves of a regional Sahelian aquifer. Hydrol. Sci. J. 56(7), 1242–1264.},
	number = {7},
	urldate = {2014-03-27},
	journal = {Hydrological Sciences Journal},
	author = {Massuel, S. and Cappelaere, B. and Favreau, G. and Leduc, C. and Lebel, T. and Vischel, T.},
	year = {2011},
	keywords = {Semi-arid, Runoff, AMMA-CATCH, Niger, climate-change, HYBIS, endoreic catchment, hydrologic process simulation, west-africa, Recharge, land-surface, southwestern niger, African monsoon, aquifer recharge, basin, groundwater modelling, Impacts, Rainfall-runoff modelling, ungauged catchment},
	pages = {1242--1264},
}

@article{lohou_surface_2014,
	title = {Surface response to rain events throughout the {West} {African} monsoon},
	volume = {14},
	issn = {1680-7324},
	url = {http://www.atmos-chem-phys.net/14/3883/2014/},
	doi = {10.5194/acp-14-3883-2014},
	abstract = {This study analyses the response of the continental surface to rain events, taking advantage of the long-term near-surface measurements over different vegetation types at different latitudes, acquired during the African Monsoon Multidisciplinary Analysis (AMMA) by the AMMA-CATCH observing system. The simulated surface response by nine land surface models involved in AMMA Land Model Intercomparison Project (ALMIP), is compared to the observations. The surface response, described via the evaporative fraction (EF), evolves in two steps: the immediate surface response (corresponding to an increase of EF occurring immediately after the rain) and the surface recovery (characterized by a decrease of EF over several days after the rain). It is shown that, for all the experimental sites, the immediate surface response is mainly dependent on the soil moisture content and the recovery period follows an exponential relationship whose rate is strongly dependent on the vegetation type (from 1 day over bare soil to 70 days over forest) and plant functional type (below and above 10 days for annual and perennial plants, respectively). The ALMIP model ensemble depicts a broad range of relationships between EF and soil moisture, with the worst results for the drier sites (high latitudes). The land surface models tend to simulate a realistic surface recovery for vegetated sites, but a slower and more variable EF decrease is simulated over bare soil than observed.},
	number = {8},
	urldate = {2014-04-19},
	journal = {Atmospheric Chemistry and Physics},
	author = {Lohou, F. and Kergoat, L. and Guichard, F. and Boone, A. and Cappelaere, B. and Cohard, J.-M. and Demarty, J. and Galle, S. and Grippa, M. and Peugeot, C. and Ramier, D. and Taylor, C. M. and Timouk, F.},
	month = apr,
	year = {2014},
	keywords = {AMMA-CATCH, HYBIS, PHYREV},
	pages = {3883--3898},
}

@article{hector_hydro-gravimetry_2014,
	title = {Hydro-gravimetry in {West}-{Africa}: {First} results from the {Djougou} ({Benin}) superconducting gravimeter},
	volume = {80},
	issn = {0264-3707},
	shorttitle = {Hydro-gravimetry in {West}-{Africa}},
	url = {http://www.sciencedirect.com/science/article/pii/S0264370714000441},
	doi = {10.1016/j.jog.2014.04.003},
	abstract = {The increasing number of hydro-gravimetry studies proves the rising interest of the hydrology community towards this monitoring method. The accuracy of Superconducting Gravimeters (SG) potentially allows the retrieval of small Water Storage Changes (WSC) down to a few millimeters of equivalent water thickness However, the importance of these corrections applied to SG data to achieve such a precision in gravity residuals should be recalled. The Djougou permanent gravity station presented in this paper and located in northern Benin, West-Africa, provides a good opportunity to review these considerations. This station is equipped since July 2010 with the superconducting gravimeter SG-060 aimed at deriving WSC at different time-scales, daily to inter-annual. In this area, WSC are 1) part of the control system for evapotranspiration (ET) process, a key variable of the West-African monsoon cycle and 2) the state variable for resource management, a critical issue in storage-poor hard rock basement contexts such as in northern Benin. The potential for deriving WSC from time-lapse gravity data partly depends on environmental features such as topography and the instrument shelter. Therefore, this issue is addressed first, with the background idea that such sensitivity analysis should be undertaken before setting up any new instrument. In Djougou, local topography is quite flat leading to a theoretical straightforward relationship between gravity changes and WSC, close to the standard Bouguer value. However, the shelter plays a significant masking role, which is the principal limitation to the retrieval of fast hydrological processes such as ET following a rain event. Several issues concerning classical gravity corrections are also addressed in the paper. These include gap-filling procedures during rain-events and drift estimates for short time series. Special attention is provided to atmospheric corrections, and different approaches are tested: a simple scalar admittance, a filtered scalar admittance, a frequency-dependent admittance and direct atmospheric loading calculations. It is shown that only the physically-based approach of direct loading calculations performs better in both residual minimization and ET retrieval. Moreover, non-local hydrological effects are investigated and account for about 20\% of the gravity residuals. Finally, gravity residuals are briefly analyzed at two distinct time scales: rapid (up to a few days) and seasonal. At the rapid time-scale, it is shown that ET retrieval is hardly achievable given shelter size and state-of-the-art atmospheric corrections. Still, mean values retrieved from this study are in accordance with known values of potential ET and constant lateral flow. Direct comparison of gravity changes with hydrological data (neutron probe monitoring and water table levels) show some discrepancies, particularly for the hydrological year of 2011, for which all hydrological data show a deficit, but SG and FG5 data do not. This preliminary analysis both provides a basis and call for further hydro-gravity modeling, to comprehensively investigate the water-cycle at the Djougou station.},
	urldate = {2014-04-19},
	journal = {Journal of Geodynamics},
	author = {Hector, Basile and Hinderer, Jacques and Séguis, Luc and Boy, Jean-Paul and Calvo, Marta and Descloitres, Marc and Rosat, Séverine and Galle, Sylvie and Riccardi, Umberto},
	year = {2014},
	keywords = {Africa, Hydrology, Hydrogeophysics, AMMA-CATCH, Gravity, Superconducting gravimeter, HYBIS, benin, PHYREV},
	pages = {34--49},
}

@article{ezzahar_combining_2009,
	title = {Combining scintillometer measurements and an aggregation scheme to estimate area-averaged latent heat flux during the {AMMA} experiment},
	volume = {375},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/pii/S0022169409000171},
	doi = {10.1016/j.jhydrol.2009.01.010},
	abstract = {This paper deals with the issue of using scintillometry in conjunction with a simple aggregation scheme to derive area-averaged sensible and latent heat fluxes over a small watershed in Niamey, Niger (Wankama catchment). Data collected in the context of the African Monsoon Multidisciplinary Analysis (AMMA) program has been used to test the proposed approach. For this purpose, a Large Aperture Scintillometer (LAS) was set up over heterogeneous surface transect of about 3.2 km spanning three vegetation types. The comparison between scintillometer-based estimates of area-averaged sensible heat fluxes and those measured by a network of the classical eddy covariance (EC) devices showed good agreement. with a relative error of about 20\% (R(2) = 0.85, RMSD = 22 W m(-2), and SEE = 21.39 W m(-2)). This is a good result considering the contrast in terms of the footprint scales associated with the two devices, which is amplified by the heterogeneity of the catchment. The results also showed that using the LAS-derived values of area-average sensible heat flux in conjunction with a simple aggregation rule to estimate area-average available energy led to a reasonable prediction of area-averaged latent heat flux (R(2) = 0.75, RMSD = 64 W m(-2) and SEE = 50 W m(-2)), when compared to those measured using the EC network. This is of interest since the LAS can potentially be used to validate estimates of surface fluxes, based on the meso-scale model, as well as those estimated using coarse-scale remote sensing-based algorithm. (C) 2009 Published by Elsevier B.V.},
	language = {English},
	number = {1-2},
	journal = {Journal of Hydrology},
	author = {Ezzahar, J. and Chehbouni, A. and Hoedjes, J. and Ramier, D. and Boulain, N. and Boubkraoui, S. and Cappelaere, B. and Descroix, L. and Mougenot, B. and Timouk, F.},
	month = aug,
	year = {2009},
	keywords = {Eddy covariance, Scintillometry, Aggregation schemes, Non-uniform and heterogeneous surfaces, Regional surfaces fluxes, AMMA-CATCH, niger, HYBIS, land-surface, evaporative fraction, flevoland field experiment, heterogeneous surface, large-aperture scintillometer, net-radiation, radiometric temperature, remotely-sensed data, surface-energy balance, water-vapor},
	pages = {217--226},
}

@article{pedinotti_evaluation_2012,
	title = {Evaluation of the {ISBA}-{TRIP} continental hydrologic system over the {Niger} basin using in situ and satellite derived datasets},
	volume = {16},
	issn = {1027-5606},
	doi = {10.5194/hess-16-1745-2012},
	abstract = {During the 1970s and 1980s, West Africa has faced extreme climate variations with extended drought conditions. Of particular importance is the Niger basin, since it traverses a large part of the Sahel and is thus a critical source of water for an ever-increasing local population in this semi arid region. However, the understanding of the hydrological processes over this basin is currently limited by the lack of spatially distributed surface water and discharge measurements. The purpose of this study is to evaluate the ability of the ISBA-TRIP continental hydrologic system to represent key processes related to the hydrological cycle of the Niger basin. ISBA-TRIP is currently used within a coupled global climate model, so that the scheme must represent the first order processes which are critical for representing the water cycle while retaining a limited number of parameters and a simple representation of the physics. To this end, the scheme uses first-order approximations to account explicitly for the surface river routing, the floodplain dynamics, and the water storage using a deep aquifer reservoir. In the current study, simulations are done at a 0.5 by 0.5A degrees spatial resolution over the 2002-2007 period (in order to take advantage of the recent satellite record and data from the African Monsoon Multidisciplinary Analyses project, AMMA). Four configurations of the model are compared to evaluate the separate impacts of the flooding scheme and the aquifer on the water cycle. Moreover, the model is forced by two different rainfall datasets to consider the sensitivity of the model to rainfall input uncertainties. The model is evaluated using in situ discharge measurements as well as satellite derived flood extent, total continental water storage changes and river height changes. The basic analysis of in situ discharges confirms the impact of the inner delta area, known as a significant flooded area, on the discharge, characterized by a strong reduction of the streamflow after the delta compared to the streamflow before the delta. In the simulations, the flooding scheme leads to a non-negligible increase of evaporation over large flooded areas, which decreases the Niger river flow by 15\% to 50\% in the locations situated after the inner delta as a function of the input rainfall dataset used as forcing. This improves the simulation of the river discharge downstream of the delta, confirming the need for coupling the land surface scheme with the flood model. The deep aquifer reservoir improves Niger low flows and the recession law during the dry season. The comparison with 3 satellite products from the Gravity Recovery and Climated Experiment (GRACE) shows a non negligible contribution of the deeper soil layers to the total storage (34\% for groundwater and aquifer). The simulations also show a non negligible sensitivity of the simulations to rain uncertainties especially concerning the discharge. Finally, sensitivity tests show that a good parameterization of routing is required to optimize simulation errors. Indeed, the modification of certain key parameters which can be observed from space (notably river height and flooded zones height changes and extent) has an impact on the model dynamics, thus it is suggested that improving the model input parameters using future developments in remote sensing technologies such as the joint CNES-NASA satellite project SWOT (Surface Water Ocean Topography), which will provide water heights and extentat land surface with an unprecedented 50-100 m resolution and precision.},
	language = {English},
	number = {6},
	journal = {Hydrology and Earth System Sciences},
	author = {Pedinotti, V. and Boone, A. and Decharme, B. and Cretaux, J. F. and Mognard, N. and Panthou, G. and Papa, F. and Tanimoun, B. A.},
	year = {2012},
	keywords = {model, climate, AMMA-CATCH, river-basin, simulation, HYBIS, variability, soil-moisture, flow, water, global evaluation, land-surface processes},
	pages = {1745--1773},
}

@article{uijlenhoet_path-average_2011,
	title = {Path-{Average} {Rainfall} {Estimation} from {Optical} {Extinction} {Measurements} {Using} a {Large}-{Aperture} {Scintillometer}},
	volume = {12},
	issn = {1525-755X},
	url = {http://dx.doi.org/10.1175/2011JHM1350.1},
	doi = {10.1175/2011JHM1350.1},
	abstract = {The potential of a near-infrared large-aperture boundary layer scintillometer as path-average rain gauge is investigated. The instrument was installed over a 2.4-km path in Benin as part of the African Monsoon Multidisciplinary Analysis (AMMA) Enhanced Observation Period during 2006 and 2007. Measurements of the one-minute-average received signal intensity were collected for 6 rainfall events during the dry season and 16 events during the rainy season. Using estimates of the signal base level just before the onset of the rainfall events, the optical extinction coefficient is estimated from the path-integrated attenuation for each minute. The corresponding path-average rain rates are computed using a power-law relation between the optical extinction coefficient and rain rate obtained from measurements of raindrop size distributions with an optical spectropluviometer and a scaling-law formalism for describing raindrop size distribution variations. Comparisons of five-minute rainfall estimates with measurements from two nearby rain gauges show that the temporal dynamics are generally captured well by the scintillometer. However, the instrument has a tendency to underestimate rain rates and event total rain amounts with respect to the gauges. It is shown that this underestimation can be explained partly by systematic differences between the actual and the employed mean power-law relation between rain rate and specific attenuation, partly by unresolved spatial and temporal rainfall variations along the scintillometer path. Occasionally, the signal may even be lost completely. It is demonstrated that if these effects are properly accounted for by employing appropriate relations between rain rate and specific attenuation and by adapting the pathlength to the local rainfall climatology, scintillometer-based rainfall estimates can be within 20\% of those estimated using rain gauges. These results demonstrate the potential of large-aperture scintillometers to estimate path-average rain rates at hydrologically relevant scales.},
	language = {English},
	number = {5},
	journal = {Journal of Hydrometeorology},
	author = {Uijlenhoet, R. and Cohard, J.-M. and Gosset, M.},
	month = oct,
	year = {2011},
	keywords = {Precipitation, AMMA-CATCH, HYBIS, benin, attenuation, raindrop size distribution, flevoland field experiment, area, beer-lambert law, heterogeneous land-surface, multiple-scattering corrections, scintillation, sensible heat fluxes},
	pages = {955--972},
}

@article{louvet_smos_2015,
	title = {{SMOS} soil moisture product evaluation over {West}-{Africa} from local to regional scale},
	volume = {156},
	issn = {0034-4257},
	url = {http://www.sciencedirect.com/science/article/pii/S0034425714004015},
	doi = {10.1016/j.rse.2014.10.005},
	abstract = {This paper assessed the SMOS soil moisture values from Level 3 (SMOS L3SM) product provided by the French CNES-CATDS. The evaluation was conducted at the local scale through comparison with ground-based soil moisture measurements acquired in Mali, Niger and Benin from 2010 to 2012. The SMOS L3SM product was compared to three other satellite-based soil moisture products. It was found that, in average over the three sites, the SMOS L3SM product provided the best coefficients of correlation and the lowest root mean square errors (RMSE). The second part of the paper is devoted to retrieve soil moisture estimates between successive SMOS soil moisture measurements in order to increase the temporal resolution. The result of the methodology allows obtaining 3-hour soil moisture mapping over West Africa with a coefficient of correlation greater than 0.82, and an RMSE lower than 0.030 m3 m− 3 in Niger and Mali and lower than 0.044 m3 m− 3 in Benin.},
	urldate = {2015-01-06},
	journal = {Remote Sensing of Environment},
	author = {Louvet, Samuel and Pellarin, Thierry and al Bitar, Ahmad and Cappelaere, Bernard and Galle, Sylvie and Grippa, Manuela and Gruhier, Claire and Kerr, Yann and Lebel, Thierry and Mialon, Arnaud and Mougin, Eric and Quantin, Guillaume and Richaume, Philippe and de Rosnay, Patricia},
	month = jan,
	year = {2015},
	keywords = {Remote sensing, remote sensing, Soil moisture, AMMA-CATCH, SMOS, Rainfall estimation, West-Africa, HYBIS, AO, PHYREV, west-africa, rainfall estimation},
	pages = {383--394},
}

@article{panthou_recent_2014,
	title = {Recent trends in the regime of extreme rainfall in the {Central} {Sahel}},
	volume = {34},
	copyright = {© 2014 The Authors. International Journal of Climatology published by John Wiley \& Sons Ltd on behalf of the Royal Meteorological Society, This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.},
	issn = {1097-0088},
	url = {http://onlinelibrary.wiley.com/doi/10.1002/joc.3984/abstract},
	doi = {10.1002/joc.3984},
	abstract = {Ongoing global warming raises the hypothesis of an intensification of the hydrological cycle, extreme rainfall events becoming more frequent. However, the strong time–space variability of extreme rainfall makes it difficult to detect meaningful trends in the regime of their occurrence for recent years. Using an integrated regional approach, it is shown that over the last 10 years, the Sahelian rainfall regime is characterized by a lasting deficit of the number of rainy days, while at the same time the extreme rainfall occurrence is on the rise. As a consequence, the proportion of annual rainfall associated with extreme rainfall has increased from 17\% in 1970–1990 to 19\% in 1991–2000 and to 21\% in 2001–2010. This tends to support the idea that a more extreme climate has been observed over 2001–2010: this climate is drier in the sense of a persisting deficit of rainfall occurrence compared to 1950–1969, while at the same time there is an increased probability of extreme daily rainfall.},
	language = {en},
	number = {15},
	urldate = {2015-01-06},
	journal = {International Journal of Climatology},
	author = {Panthou, G. and Vischel, T. and Lebel, T.},
	year = {2014},
	keywords = {Sahel, extreme rainfall, hydrological cycle intensification, AMMA-CATCH, HYBIS, PHYREV},
	pages = {3998--4006},
}

@article{velluet_building_2014,
	title = {Building a field- and model-based climatology of local water and energy cycles in the cultivated {Sahel} – annual budgets and seasonality},
	volume = {18},
	issn = {1607-7938},
	url = {http://www.hydrol-earth-syst-sci.net/18/5001/2014/},
	doi = {10.5194/hess-18-5001-2014},
	abstract = {In the sub-Saharan Sahel, energy and water cycling at the land surface is pivotal for the regional climate, water resources and land productivity, yet it is still very poorly documented. As a step towards a comprehensive climatological description of surface fluxes in this area, this study provides estimates of long-term average annual budgets and seasonal cycles for two main land use types of the cultivated Sahelian belt: rainfed millet crop and fallow bush. These estimates build on the combination of a 7-year field data set from two typical plots in southwestern Niger with detailed physically based soil–plant–atmosphere modeling, yielding a continuous, comprehensive set of water and energy flux and storage variables over this multiyear period. In the present case in particular, blending field data with mechanistic modeling makes the best use of available data and knowledge for the construction of the multivariate time series. Rather than using the model only to gap-fill observations into a composite series, model–data integration is generalized homogeneously over time by generating the whole series with the entire data-constrained model simulation. Climatological averages of all water and energy variables, with associated sampling uncertainty, are derived at annual to sub-seasonal scales from the time series produced. Similarities and differences in the two ecosystem behaviors are highlighted. Mean annual evapotranspiration is found to represent {\textbackslash}textasciitilde82–85\% of rainfall for both systems, but with different soil evaporation/plant transpiration partitioning and different seasonal distribution. The remainder consists entirely of runoff for the fallow, whereas drainage and runoff stand in a 40–60\% proportion for the millet field. These results should provide a robust reference for the surface energy- and water-related studies needed in this region. Their significance and the benefits they gain from the innovative data–model integration approach are thoroughly discussed. The model developed in this context has the potential for reliable simulations outside the reported conditions, including changing climate and land cover.},
	number = {12},
	urldate = {2015-01-07},
	journal = {Hydrol. Earth Syst. Sci.},
	author = {Velluet, C. and Demarty, J. and Cappelaere, B. and Braud, I. and Issoufou, H. B.-A. and Boulain, N. and Ramier, D. and Mainassara, I. and Charvet, G. and Boucher, M. and Chazarin, J.-P. and Oï, M. and Yahou, H. and Maidaji, B. and Arpin-Pont, F. and Benarrosh, N. and Mahamane, A. and Nazoumou, Y. and Favreau, G. and Seghieri, J.},
	month = dec,
	year = {2014},
	keywords = {model, AMMA-CATCH, niger, PHYREV},
	pages = {5001--5024},
}

@article{vouillamoz_use_2014,
	title = {The use of magnetic resonance sounding for quantifying specific yield and transmissivity in hard rock aquifers: {The} example of {Benin}},
	volume = {107},
	issn = {0926-9851},
	shorttitle = {The use of magnetic resonance sounding for quantifying specific yield and transmissivity in hard rock aquifers},
	url = {http://www.sciencedirect.com/science/article/pii/S0926985114001463},
	doi = {10.1016/j.jappgeo.2014.05.012},
	abstract = {Hundreds of thousands of boreholes have been drilled in hard rocks of Africa and Asia for supplying human communities with drinking water. Despite the common use of geophysics for improving the siting of boreholes, a significant number of drilled holes does not deliver enough water to be equipped (e.g. 40\% on average in Benin). As compared to other non-invasive geophysical methods, magnetic resonance sounding (MRS) is selective to groundwater. However, this distinctive feature has not been fully used in previous published studies for quantifying the drainable groundwater in hard rocks (i.e. the specific yield) and the short-term productivity of aquifer (i.e. the transmissivity). We present in this paper a comparison of MRS results (i.e. the water content and pore-size parameter) with both specific yield and transmissivity calculated from long duration pumping tests. We conducted our experiments in six sites located in different hard rock groups in Benin, thus providing a unique data set to assess the usefulness of MRS in hard rock aquifers. We found that the MRS water content is about twice the specific yield. We also found that the MRS pore-size parameter is well correlated with the specific yield. Thus we proposed two linear equations for calculating the specific yield from the MRS water content (with an uncertainty of about 10\%) and from the pore-size parameter (with an uncertainty of about 20\%). The later has the advantage of defining a so-named MRS cutoff time value for indentifying non-drainable MRS water content and thus low groundwater reserve. We eventually propose a nonlinear equation for calculating the specific yield using jointly the MRS water content and the pore-size parameters, but this approach has to be confirmed with further investigations. This study also confirmed that aquifer transmissivity can be estimated from MRS results with an uncertainty of about 70\%. We conclude that MRS can be usefully applied for estimating aquifer specific yield and transmissivity in weathered hard rock aquifers. Our result will contribute to the improvement of well siting and groundwater management in hard rocks.},
	urldate = {2014-06-01},
	journal = {Journal of Applied Geophysics},
	author = {Vouillamoz, J. M. and Lawson, F. M. A. and Yalo, N. and Descloitres, M.},
	month = aug,
	year = {2014},
	keywords = {Hard rock aquifers, Hydrogeophysics, Magnetic resonance sounding, SNMR, Specific yield, Transmissivity, AMMA-CATCH, HYBIS, benin, PHYREV, transmissivity, snmr, socle},
	pages = {16--24},
}

@article{boucher_constraining_2012,
	title = {Constraining {Groundwater} {Modeling} with {Magnetic} {Resonance} {Soundings}},
	volume = {50},
	copyright = {© 2011, The Author(s). Ground Water © 2011, National Ground Water Association},
	issn = {1745-6584},
	url = {http://onlinelibrary.wiley.com/doi/10.1111/j.1745-6584.2011.00891.x/abstract},
	doi = {10.1111/j.1745-6584.2011.00891.x},
	abstract = {Magnetic resonance sounding (MRS) is a noninvasive geophysical method that allows estimating the free water content and transmissivity of aquifers. In this article, the ability of MRS to improve the reliability of a numerical groundwater model is assessed. Thirty-five sites were investigated by MRS over a ∼5000 km2 domain of the sedimentary Continental Terminal aquifer in SW Niger. Time domain electromagnetic soundings were jointly carried out to estimate the aquifer thickness. A groundwater model was previously built for this section of the aquifer and forced by the outputs from a distributed surface hydrology model, to simulate the observed long-term (1992 to 2003) rise in the water table. Uncertainty analysis had shown that independent estimates of the free water content and transmissivity values of the aquifer would facilitate cross-evaluation of the surface-water and groundwater models. MRS results indicate ranges for permeability (K = 1 × 10−5 to 3 × 10−4 m/s) and for free water content (w = 5\% to 23\% m3/m3) narrowed by two orders of magnitude (K) and by ∼50\% (w), respectively, compared to the ranges of permeability and specific yield values previously considered. These shorter parameter ranges result in a reduction in the model's equifinality (whereby multiple combinations of model's parameters are able to represent the same observed piezometric levels), allowing a better constrained estimate to be derived for net aquifer recharge (∼22 mm/year).},
	language = {en},
	number = {5},
	urldate = {2014-06-13},
	journal = {Ground Water},
	author = {Boucher, Marie and Favreau, Guillaume and Nazoumou, Yahaya and Cappelaere, Bernard and Massuel, Sylvain and Legchenko, Anatoly},
	month = sep,
	year = {2012},
	keywords = {AMMA-CATCH, HYBIS, aquifer characterization, endoreic catchment, hydrologic process simulation, sahelian west niger, Recharge, semiarid niger, hydrogeology, resolution},
	pages = {775--784},
}

@article{hinderer_land_2011,
	title = {Land {Water} {Storage} {Changes} from {Ground} and {Space} {Geodesy}: {First} {Results} from the {GHYRAF} ({Gravity} and {Hydrology} in {Africa}) {Experiment}},
	volume = {169},
	issn = {0033-4553},
	shorttitle = {Land {Water} {Storage} {Changes} from {Ground} and {Space} {Geodesy}},
	url = {http://link.springer.com/article/10.1007/s00024-011-0417-9},
	doi = {10.1007/s00024-011-0417-9},
	abstract = {This paper is devoted to the first results from the GHYRAF (Gravity and Hydrology in Africa) experiment conducted since 2008 in West Africa and is aimed at investigating the changes in water storage in different regions sampling a strong rainfall gradient from the Sahara to the monsoon zone. The analysis of GPS vertical displacement in Niamey (Niger) and Djougou (Benin) shows that there is a clear annual signature of the hydrological load in agreement with global hydrology models like GLDAS. The comparison of GRACE solutions in West Africa, and more specifically in the Niger and Lake Chad basins, reveals a good agreement for the large scale annual water storage changes between global hydrology models and space gravity observations. Ground gravity observations done with an FG5 absolute gravimeter also show signals which can be well related to measured changes in soil and ground water. We present the first results for two sites in the Sahelian band (Wankama and Diffa in Niger) and one (Djougou in Benin) in the Sudanian monsoon region related to the recharge–discharge processes due to the monsoonal event in summer 2008 and the following dry season. It is confirmed that ground gravimetry is a useful tool to constrain local water storage changes when associated to hydrological and subsurface geophysical in situ measurements.},
	language = {en},
	number = {8},
	urldate = {2014-06-13},
	journal = {Pure and Applied Geophysics},
	author = {Hinderer, J. and Pfeffer, J. and Boucher, M. and Nahmani, S. and Linage, C. De and Boy, J.-P. and Genthon, P. and Séguis, L. and Favreau, G. and Bock, O. and Descloitres, M.},
	year = {2011},
	keywords = {Sahel, Earth and Environmental Science, AMMA-CATCH, GPS, Water storage, grace, mrs, African monsoon, Geophysics/Geodesy, gravimetry},
	pages = {1391--1410},
}

@article{saux-picart_sethys_savannah_2009,
	title = {{SEtHyS}\_Savannah: {A} multiple source land surface model applied to {Sahelian} landscapes},
	volume = {149},
	issn = {0168-1923},
	shorttitle = {{SEtHyS}\_Savannah},
	url = {http://www.sciencedirect.com/science/article/pii/S0168192309000847},
	doi = {10.1016/j.agrformet.2009.03.013},
	abstract = {The existing SEtHyS SVAT model was developed further to model heat and water fluxes over savannah landscapes with the final objective to use remote sensing for regionalization and monitoring at larger scale. This new development incorporates two vegetation layers (low and high covers) above the soil. The transfer of soil water was revised in order to improve the simulated hydrology over Sahelian and semi-arid regions, by incorporating a mulch representation in a three-layer soil scheme. The two versions of the model, original and modified, have been compared at local scale over two instrumented local sites of the AMMA-Niger supersite: a fallow and a millet field equipped with surface flux, soil moisture and vegetation measurements. After calibration of the model parameters using the Multiobjective Calibration Iterative Process (MCIP) methodology on the 2005 dataset, the simulations of the two versions of SEtHyS were compared to observations over 2006. Significant differences were found between the simulations, and a better agreement with in situ measurements was observed for the new model. These differences are discussed in relation to the parameterizations of the hydrological and vegetation processes.},
	language = {en},
	number = {9},
	urldate = {2014-06-13},
	journal = {Agricultural and Forest Meteorology},
	author = {Saux-Picart, S. and Ottlé, C. and Perrier, A. and Decharme, B. and Coudert, B. and Zribi, M. and Boulain, N. and Cappelaere, B. and Ramier, D.},
	month = sep,
	year = {2009},
	keywords = {Surface fluxes, SVAT, Sahel, Plant canopy modelling, Savannah, Soil surface mulch, AMMA-CATCH},
	pages = {1421--1432},
}

@article{ago_long_2014,
	title = {Long term observations of carbon dioxide exchange over cultivated savanna under a {Sudanian} climate in {Benin} ({West} {Africa})},
	volume = {197},
	issn = {0168-1923},
	url = {http://www.sciencedirect.com/science/article/pii/S0168192314001476},
	doi = {10.1016/j.agrformet.2014.06.005},
	abstract = {Abstract Turbulent CO2 exchanges between a cultivated Sudanian savanna and the atmosphere were measured during 29 months (August 2007–December 2009) by an eddy-covariance system in North-Western Benin, West Africa. The site (Lat 9.74° N, Long 1.60° E, Alt: 449 m) is the one of three sites fitted out by the international AMMA-CATCH program. The flux station footprint area is mainly composed of herbs and crops with some sparse trees and shrubs. Fluxes data were completed by an inventory of dominating species around the tower and the meteorological measurements. Flux response to climatic and edaphic factors was studied. Water was found the main controlling factor of ecosystem dynamics: much larger uptake was found in wet than dry season. During wet season, a very clear answer of net CO2 fluxes to photosynthetic photon fluxes density (PPFD) was observed. A low limitation in response to saturation deficit and soil water variability was however observed. The total ecosystem respiration (TER) was found highly dependent on soil moisture below 0.1 m3 m−3, but saturates above this threshold. The average annual carbon sequestration was 232 ± 27 gC m−2 with its inter-annual variability mainly controlled by TER. Finally, the ecosystem appeared more efficient during morning and wet season than during afternoon and dry period.},
	language = {en},
	urldate = {2014-06-26},
	journal = {Agricultural and Forest Meteorology},
	author = {Ago, Expedit Evariste and Agbossou, Euloge Kossi and Galle, Sylvie and Cohard, Jean-Martial and Heinesch, Bernard and Aubinet, Marc},
	month = oct,
	year = {2014},
	keywords = {Annual sequestration, Eddy-covariance, Net ecosystem exchange, Savanna, Sudanian climate, West Africa, AMMA-CATCH, HYBIS, benin, Nalohou, PHYREV},
	pages = {13--25},
}

@article{descloitres_contribution_2011,
	title = {The contribution of {MRS} and resistivity methods to the interpretation of actual evapo-transpiration measurements: a case study in metamorphic context in north {Bénin}},
	volume = {9},
	issn = {18730604},
	shorttitle = {The contribution of {MRS} and resistivity methods to the interpretation of actual evapo-transpiration measurements},
	url = {http://nsg.eage.org/publication/publicationdetails/?publication=49239},
	doi = {10.3997/1873-0604.2011003},
	abstract = {A quantitative budget estimate of actual evapo-transpiration is a key issue for enhanced hydrological modelling in northern Bénin. Actual evapo-transpiration is estimated using large aperture scintillometer equipment, devoted to sensible heat flux measurements. However, a previous study reported that the actual evapo-transpiration cycle is not fully understood. Indeed, the actual evapo-transpiration depends strongly on several factors such as climate, vegetation pattern, soil water storage and human activities. The respective contributions of the aquifer and vadose zone to the actual evapo-transpiration budget are not known. When using piezometric variations of the water table, the aquifer contribution is not easy to quantify since the specific yield may vary in the investigated area, located in a metamorphic rock environment. In the present study, we investigate whether significant differences in the aquifer’s specific yield could exist within the large aperture scintillometer measurement area, leading to different actual evapo-transpiration water losses. We use joint frequency electromagnetic resistivity mapping, geological surveys and magnetic resonance sounding (MRS) to delineate the effective porosity of the regolith around the scintillometre measurement area. Thirteen MRS soundings implemented in key areas reveal a clear classification of the main geological units on the basis of their water content. The MRS water content varies between 1.5–3\% for amphibolite and micaschists formations to more than 12\% for quartzitic fractured formations, whereas the MRS relaxation time T1 is less discriminating (150–250 ms), indicating a small variation in pore size. Then, as a first modelling exercise, we assumed that the MRS water content (the effective porosity) maximizes the specific yield. The actual evapo-transpiration budget given by a previous study (Guyot et al. 2009) is then re-interpreted using geophysical data: we found that a) the measured water table depletion can explain the actual evapo-transpiration value providing enough water for the transpiration process and b) the significant discrepancies in actual evapo-transpiration signals observed between the eastern and western parts of the watershed can be explained by the respective effective porosity of the geological units. Even if further research is needed to link MRS water content to the specific yield and to evaluate a possible role of the deep vadose zone, the hydrogeophysical mapping presented in this study highlights the role of the MRS method for providing relevant information to understand hydrological processes in this complicated geological context of north Bénin.},
	language = {en},
	number = {1780},
	urldate = {2016-04-13},
	journal = {Near Surface Geophysics},
	author = {Descloitres, M. and Séguis, L. and Legchenko, A. and Wubda, M. and Guyot, A. and Cohard, J-M.},
	month = apr,
	year = {2011},
	keywords = {AMMA-CATCH, HYBIS},
}

@article{brandt_assessing_2016,
	title = {Assessing woody vegetation trends in {Sahelian} drylands using {MODIS} based seasonal metrics},
	volume = {183},
	issn = {0034-4257},
	url = {https://www.sciencedirect.com/science/article/pii/S0034425716302280},
	doi = {10.1016/j.rse.2016.05.027},
	abstract = {Woody plants play a major role for the resilience of drylands and in peoples' livelihoods. However, due to their scattered distribution, quantifying and monitoring woody cover over space and time is challenging. We develop a phenology driven model and train/validate MODIS (MCD43A4, 500m) derived metrics with 178 ground observations from Niger, Senegal and Mali to estimate woody cover trends from 2000 to 2014 over the entire Sahel. The annual woody cover estimation at 500m scale is fairly accurate with an RMSE of 4.3 (woody cover \%) and r2=0.74. Over the 15year period we observed an average increase of 1.7 (±5.0) woody cover (\%) with large spatial differences: No clear change can be observed in densely populated areas (0.2±4.2), whereas a positive change is seen in sparsely populated areas (2.1±5.2). Woody cover is generally stable in cropland areas (0.9±4.6), reflecting the protective management of parkland trees by the farmers. Positive changes are observed in savannas (2.5±5.4) and woodland areas (3.9±7.3). The major pattern of woody cover change reveals strong increases in the sparsely populated Sahel zones of eastern Senegal, western Mali and central Chad, but a decreasing trend is observed in the densely populated western parts of Senegal, northern Nigeria, Sudan and southwestern Niger. This decrease is often local and limited to woodlands, being an indication of ongoing expansion of cultivated areas and selective logging. We show that an overall positive trend is found in areas of low anthropogenic pressure demonstrating the potential of these ecosystems to provide services such as carbon storage, if not over-utilized. Taken together, our results provide an unprecedented synthesis of woody cover dynamics in the Sahel, and point to land use and human population density as important drivers, however only partially and locally offsetting a general post-drought increase.},
	language = {en},
	urldate = {2016-06-30},
	journal = {Remote Sensing of Environment},
	author = {Brandt, Martin and Hiernaux, Pierre and Rasmussen, Kjeld and Mbow, Cheikh and Kergoat, Laurent and Tagesson, Torbern and Ibrahim, Yahaya Z. and Wélé, Abdoulaye and Tucker, Compton J. and Fensholt, Rasmus},
	month = sep,
	year = {2016},
	keywords = {Sahel, AMMA-CATCH, ext1, Carbon stocks, Deforestation, Human population density, MCD43, Woody cover, AO},
	pages = {215--225},
}

@article{leroux_assimilation_2016,
	title = {Assimilation of {SMOS} soil moisture into a distributed hydrological model and impacts on the water cycle variables over the {Ouémé} catchment in {Benin}},
	volume = {20},
	issn = {1607-7938},
	url = {http://www.hydrol-earth-syst-sci.net/20/2827/2016/},
	doi = {10.5194/hess-20-2827-2016},
	language = {en},
	number = {7},
	urldate = {2016-07-26},
	journal = {Hydrology and Earth System Sciences},
	author = {Leroux, Delphine J. and Pellarin, Thierry and Vischel, Théo and Cohard, Jean-Martial and Gascon, Tania and Gibon, François and Mialon, Arnaud and Galle, Sylvie and Peugeot, Christophe and Séguis, Luc},
	month = jul,
	year = {2016},
	keywords = {AMMA-CATCH, Benin, PHYREV},
	pages = {2827--2840},
}

@article{robert_monitoring_2016,
	title = {Monitoring water turbidity and surface suspended sediment concentration of the {Bagre} {Reservoir} ({Burkina} {Faso}) using {MODIS} and field reflectance data},
	volume = {52},
	issn = {03032434},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0303243416300988},
	doi = {10.1016/j.jag.2016.06.016},
	abstract = {Monitoring turbidity and Surface Suspended Sediment Concentration (SSSC) of inland waters is essential to address several important issues: erosion, sediment transport and deposition throughout watersheds, reservoir siltation, water pollution, human health risks, etc. This is especially important in regions with limited conventional monitoring capacities such as West Africa. In this study, we explore the use of Moderate Resolution Imaging Spectroradiometer data (MODIS, MOD09Q1 and MYD09Q1 products, red (R) and near infrared (NIR) bands) to monitor turbidity and SSSC for the Bagre Reservoir in Burkina Faso. High values ​​of these parameters associated with high spatial and temporal variability potentially challenge the methodologies developed so far for less turbid waters. Field measurements (turbidity, SSSC, radiometry) are used to evaluate different radiometric indices. The NIR/R ratio is found to be the most suited to retrieve SSSC and turbidity for both in-situ spectoradiometer measurements and satellite reflectance from MODIS. The spatio temporal variability of MODIS NIR/R together with rainfall estimated by the Tropical Rainforest Measuring Mission (TRMM) and altimetry data from Jason-2 is analyzed over the Bagre Reservoir for the 2000–2015 period. It is found that rain events of the early rainy season (February-March) through mid-rainy season (August) are decisive in triggering turbidity increase. Sediment transport is observed in the reservoir from upstream to downstream between June and September. Furthermore, a significant increase of 19\% in turbidity values is observed between 2000 and 2015, mainly for the July to December period. It is especially well marked for August, with the central and downstream areas showing the largest increase. The most probable hypothesis to explain this evolution is a change in land use, and particularly an increase in the amount of bare soils, which enhances particle transport by runoff.},
	language = {en},
	urldate = {2016-10-10},
	journal = {International Journal of Applied Earth Observation and Geoinformation},
	author = {Robert, Elodie and Grippa, Manuela and Kergoat, Laurent and Pinet, Sylvain and Gal, Laetitia and Cochonneau, Gérard and Martinez, Jean-Michel},
	month = oct,
	year = {2016},
	keywords = {Burkina Faso, Sahel, AMMA-CATCH, African reservoir, Modis, Radiometry, Surface suspended sediment concentration, Turbidity, Water color},
	pages = {243--251},
}

@article{grippa_modelling_2017,
	title = {Modelling surface runoff and water fluxes over contrasted soils in pastoral {Sahel}: evaluation of the {ALMIP2} land surface models over the {Gourma} region in {Mali}},
	volume = {18},
	issn = {1525-755X, 1525-7541},
	shorttitle = {Modelling surface runoff and water fluxes over contrasted soils in pastoral {Sahel}},
	url = {http://journals.ametsoc.org/doi/10.1175/JHM-D-16-0170.1},
	doi = {10.1175/jhm-d-16-0170.1},
	abstract = {AbstractLand surface processes play an important role in the West African monsoon variability. In addition, the evolution of hydrological systems in this region, and particularly the increase of surface water and runoff coefficients observed since the 1950s, has had a strong impact on water resources and on the occurrence of floods events. This study addresses results from phase 2 of the African Monsoon Multidisciplinary Analysis (AMMA) Land Surface Model Intercomparison Project (ALMIP2), carried out to evaluate the capability of different state-of-the-art land surface models to reproduce surface processes at the mesoscale. Evaluation of runoff and water fluxes over the Mali site is carried out through comparison with runoff estimations over endorheic watersheds as well as evapotranspiration (ET) measurements. Three remote-sensing-based ET products [ALEXI, MODIS, and Global Land Evaporation Amsterdam Model (GLEAM)] are also analyzed. It is found that, over deep sandy soils, surface runoff is generally overestimated, but the ALMIP2 multimodel mean reproduces in situ measurements of ET and water stress events rather well. However, ALMIP2 models are generally unable to distinguish among the two contrasted hydrological systems typical of the study area. Employing as input a soil map that explicitly represents shallow soils improves the representation of water fluxes for the models that can account for their representation. Shallow soils are shown to be also quite challenging for remote-sensing-based ET products, even if their effect on evaporative loss was captured by the diagnostic thermal-based ALEXI. A better representation of these soils, in soil databases, model parameterizations, and remote sensing algorithms, is fundamental to improve the estimation of water fluxes in this part of the Sahel.},
	language = {en},
	number = {7},
	urldate = {2017-01-16},
	journal = {Journal of Hydrometeorology},
	author = {Grippa, Manuela and Kergoat, Laurent and Boone, Aaron and Peugeot, Christophe and Demarty, Jérôme and Cappelaere, Bernard and Gal, Laetitia and Hiernaux, Pierre and Mougin, Eric and Ducharne, Agnès and Dutra, Emanuel and Anderson, Martha and Hain, Christopher and Group, {and} ALMIP2 Working},
	month = jan,
	year = {2017},
	keywords = {Remote sensing, Africa, Land surface model, Model comparison, Land surface, Surface observations, AMMA-CATCH, Mali, PHYREV, Almip2},
	pages = {1847--1866},
}

@article{wubda_time-lapse_2017,
	title = {Time-lapse electrical surveys to locate infiltration zones in weathered hard rock tropical areas},
	volume = {142},
	issn = {0926-9851},
	url = {http://www.sciencedirect.com/science/article/pii/S0926985117300952},
	doi = {10.1016/j.jappgeo.2017.01.027},
	abstract = {In West Africa, infiltration and groundwater recharge processes in hard rock areas are depending on climatic, surface and subsurface conditions, and are poorly documented. Part of the reason is that identification, location and monitoring of these processes is still a challenge. Here, we explore the potential for time-lapse electrical surveys to bring additional information on these processes for two different climate situations: a semi-arid Sahelian site (north of Burkina and a humid Sudanian site (north of Benin), respectively focusing on indirect (localized) and direct (diffuse) recharge processes. The methodology is based on surveys in dry season and rainy season on typical pond or gully using Electrical Resistivity Tomography (ERT) and frequency electromagnetic (FEM) apparent conductivity mapping. The results show that in the Sahelian zone an indirect recharge occurs as expected, but infiltration doesn't takes place at the center of the pond to the aquifer, but occurs laterally in the banks. In Sudanian zone, the ERT survey shows a direct recharge process as expected, but also a complicated behavior of groundwater dilution, as well as the role of hardpans for fast infiltration. These processes are ascertained by groundwater monitoring in adjacent observing wells. At last, FEM time lapse mapping is found to be difficult to quantitatively interpreted due to the non-uniqueness of the model, clearly evidenced comparing FEM result to auger holes monitoring. Finally, we found that time-lapse ERT can be an efficient way to track infiltration processes across ponds and gullies in both climatic conditions, the Sahelian setting providing results easier to interpret, due to significant resistivity contrasts between dry and rain seasons. Both methods can be used for efficient implementation of punctual sensors for complementary studies. However, FEM time-lapse mapping remains difficult to practice without external information that renders this method less attractive for quantitative interpretation purposes.},
	language = {en},
	urldate = {2017-06-19},
	journal = {Journal of Applied Geophysics},
	author = {Wubda, M. and Descloitres, M. and Yalo, N. and Ribolzi, O. and Vouillamoz, J-M. and Boukari, M. and Hector, B. and Séguis, L.},
	month = jul,
	year = {2017},
	keywords = {Burkina Faso, AMMA-CATCH, Benin, Hard rock, Infiltration, Resistivity, Time-lapse, PHYREV, socle, Bein},
	pages = {23--37},
}

@article{gal_paradoxical_2017,
	title = {The paradoxical evolution of runoff in the pastoral {Sahel}: analysis of the hydrological changes over the {Agoufou} watershed ({Mali}) using the {KINEROS}-2 model},
	volume = {21},
	issn = {1607-7938},
	shorttitle = {The paradoxical evolution of runoff in the pastoral {Sahel}},
	url = {https://www.hydrol-earth-syst-sci.net/21/4591/2017/},
	doi = {10.5194/hess-21-4591-2017},
	language = {en},
	number = {9},
	urldate = {2018-01-30},
	journal = {Hydrology and Earth System Sciences},
	author = {Gal, Laetitia and Grippa, Manuela and Hiernaux, Pierre and Pons, Léa and Kergoat, Laurent},
	month = sep,
	year = {2017},
	keywords = {AMMA-CATCH, Mali, attribution},
	pages = {4591--4613},
}

@article{trichon_persistent_2018,
	title = {The persistent decline of patterned woody vegetation: {The} tiger bush in the context of the regional {Sahel} greening trend},
	volume = {24},
	issn = {1354-1013},
	shorttitle = {The persistent decline of patterned woody vegetation},
	url = {http://doi.wiley.com/10.1111/gcb.14059},
	doi = {10.1111/gcb.14059},
	abstract = {Abstract Following 25 years of below average annual rainfall in the Sahel between 1970 and 1995, the return to more humid conditions has led to rapid postdrought recovery of the woody cover. However, the increase in the woody cover is not spatially homogeneous raising questions about the resilience of some woody vegetation types. Based on the analysis of field and remote sensing data collected on the tiger bush systems in the northern Sahel in Mali, this study noted the current and persistent degradation of these systems in the Sahel since the 1970s despite the recent improvement in rainfall since the mid-1990s and the general Sahel re-greening. Profound changes in the woody population pattern, tree density and cover, and floristic composition took place regardless of the site location along the south–north rainfall gradient. Associated with definite structural changes of the woody population, surface hydrology shifted from a sheet to concentrated run-off accelerating the collapse of the patterned woody population. Currently, there is no evidence in favour of reversing the current degradation process, at least at a decadal scale, although very sparse recolonization by pioneer woody vegetation has been observed in the driest sites along recently formed gullies. These observations support the hypothesis of an ecosystem shift, with long-term implications for the structure and functioning of the patterned vegetation, as well as the whole watershed landscape through increased run-off leading to stronger water flows in enlarged wadis, increased soil erosion upstream and sediment deposition downstream, enhanced water storage in ponds, and greater recharge of aquifers, which is an illustration of the “Sahelian paradox”.},
	language = {en},
	number = {6},
	urldate = {2018-02-12},
	journal = {Global Change Biology},
	author = {Trichon, Valérie and Hiernaux, Pierre and Walcker, Romain and Mougin, Eric},
	month = feb,
	year = {2018},
	keywords = {Sahel, AMMA-CATCH, ext1, AO},
	pages = {2633--2648},
}

@article{roman-cascon_correcting_2017,
	title = {Correcting satellite-based precipitation products through {SMOS} soil moisture data assimilation in two land-surface models of different complexity: {API} and {SURFEX}},
	volume = {200},
	issn = {0034-4257},
	shorttitle = {Correcting satellite-based precipitation products through {SMOS} soil moisture data assimilation in two land-surface models of different complexity},
	url = {https://www.sciencedirect.com/science/article/pii/S0034425717303905},
	doi = {10.1016/j.rse.2017.08.022},
	abstract = {Global rainfall information is useful for many applications. However, real-time versions of satellite-based rainfall products are known to contain errors. Recent studies have demonstrated how the information about rainfall intrinsically contained in soil moisture data can be utilised for improving rainfall estimates. That is, soil moisture dynamics are impacted for several days by the accumulated amount of rainfall following within a particular event. In this context, soil moisture data from the Soil Moisture Ocean Salinity (SMOS) satellite is used in this study to correct rainfall accumulation estimates provided by satellite-based real-time precipitation products such as CMORPH, TRMM-3B42RT or PERSIANN. An algorithm based on the SMOS measurements data assimilation is tested in two land-surface models of different complexity: a simple hydrological model (Antecedent Precipitation Index (API)) and a more sophisticated state-of-the-art land-surface model (SURFEX (Surface Externalisée)). We show how the assimilation technique, based on a particle filter method, generally leads to a significant improvement in rainfall estimates, with slightly better results for the simpler (and less computationally demanding) API model. This methodology has been evaluated for six years at ten sites around the world with different land use and climatological features. The results also show the limitations of the methodology in regions highly affected by mountainous terrain, forest or intense radio-frequency interference (RFI), which can notably affect the quality of the retrievals. The satisfactory results shown here invite the future operational application of the methodology in near-real time on a global scale.},
	language = {en},
	urldate = {2018-02-12},
	journal = {Remote Sensing of Environment},
	author = {Román-Cascón, Carlos and Pellarin, Thierry and Gibon, François and Brocca, Luca and Cosme, Emmanuel and Crow, Wade and Fernández-Prieto, Diego and Kerr, Yann H. and Massari, Christian},
	month = oct,
	year = {2017},
	keywords = {Rainfall, Soil moisture, AMMA-CATCH, SMOS, API, Particle filter, SURFEX, AO, PHYREV},
	pages = {295--310},
}

@article{goutorbe_overview_1997,
	title = {An overview of {HAPEX}-{Sahel}: a study in climate and desertification},
	volume = {188-189},
	issn = {0022-1694},
	shorttitle = {An overview of {HAPEX}-{Sahel}},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0022169496033082},
	doi = {10.1016/S0022-1694(96)03308-2},
	language = {en},
	urldate = {2018-03-17},
	journal = {Journal of Hydrology},
	author = {Goutorbe, J.P. and Lebel, T. and Dolman, A.J. and Gash, J.H.C. and Kabat, P. and Kerr, Y.H. and Monteny, B. and Prince, S.D. and Stricker, J.N.M. and Tinga, A. and Wallace, J.S.},
	month = feb,
	year = {1997},
	keywords = {AMMA-CATCH, Hapex-Sahel},
	pages = {4--17},
}

@article{escorihuela_smos_2018,
	title = {{SMOS} based high resolution soil moisture estimates for desert locust preventive management},
	volume = {11},
	issn = {2352-9385},
	url = {https://www.sciencedirect.com/science/article/pii/S2352938517302392},
	doi = {10.1016/j.rsase.2018.06.002},
	abstract = {This paper presents the first attempt to include soil moisture information from remote sensing in the tools available to desert locust managers. The soil moisture requirements were first assessed with the users. The main objectives of this paper are: i) to describe and validate the algorithms used to produce a soil moisture dataset at 1 km resolution relevant to desert locust management based on DisPATCh methodology applied to SMOS and ii) the development of an innovative approach to derive high-resolution (100 m) soil moisture products from Sentinel-1 in synergy with SMOS data. For the purpose of soil moisture validation, 4 soil moisture stations where installed in desert areas (one in each user country). The soil moisture 1 km product was thoroughly validated and its accuracy is amongst the best available soil moisture products. Current comparison with in-situ soil moisture stations shows good values of correlation (R{\textgreater}0.7) and low RMSE (below 0.04 m3 m−3). The low number of acquisitions on wet dates has limited the development of the soil moisture 100 m product over the Users Areas. The Soil Moisture product at 1 km will be integrated into the national and global Desert Locust early warning systems in national locust centres and at DLIS-FAO, respectively.},
	language = {en},
	urldate = {2018-11-16},
	journal = {Remote Sensing Applications: Society and Environment},
	author = {Escorihuela, Maria Jose and Merlin, Olivier and Stefan, Vivien and Moyano, Gorka and Eweys, Omar Ali and Zribi, Mehrez and Kamara, Sidi and Benahi, Ahmed Salem and Ebbe, Mohamed Abdallahi Babah and Chihrane, Jamal and Ghaout, Saïd and Cissé, Sory and Diakité, Fakaba and Lazar, Mohammed and Pellarin, Thierry and Grippa, Manuela and Cressman, Keith and Piou, Cyril},
	month = aug,
	year = {2018},
	keywords = {West Africa, Remote sensing, Soil moisture, AMMA-CATCH, ext1, Sentinel-1, Desert locust management, Disaggregation, SMOS, PHYREV},
	pages = {140--150},
}

@article{wilcox_trends_2018,
	title = {Trends in hydrological extremes in the {Senegal} and {Niger} {Rivers}},
	volume = {566},
	issn = {0022-1694},
	url = {http://www.sciencedirect.com/science/article/pii/S0022169418305766},
	doi = {10.1016/j.jhydrol.2018.07.063},
	abstract = {In recent years, West Africa has witnessed an increasing number of damaging floods that raise the question of a possible intensification of the hydrological hazards in the region. In this study, the evolution of extreme floods is analyzed over the period 1950–2015 for seven tributaries in the Sudano-Guinean part of the Senegal River basin and four data sets in the Sahelian part of the Niger River basin. Non-stationary Generalized Extreme Value (NS-GEV) distributions including twelve models with time-dependent parameters plus a stationary GEV are applied to annual maxima of daily discharge (AMAX) series. An original methodology is proposed for comparing GEV models and selecting the best for use. The stationary GEV is rejected for all stations, demonstrating the significant non-stationarity of extreme discharge values in West Africa over the past six decades. The model of best fit most commonly selected is a double-linear model for the central tendency parameter (μ), with the dispersion parameter (σ) modeled as either stationary, linear, or a double-linear. Change points in double-linear models are relatively consistent for the Senegal basin, with stations switching from a decreasing streamflow trend to an increasing streamflow trend in the early 1980s. In the Niger basin the trend in μ is generally positive since the 1970s with an increase in slope after the change point, but the change point location is less consistent. The recent increasing trends in extreme discharges are reflected in an especially marked increase in return level magnitudes since the 1980s in the studied Sahelian rivers. The rate of the increase indicated by the study results raises urgent considerations for stakeholders and engineers who are in charge of river basin management and hydraulic works sizing.},
	language = {en},
	urldate = {2018-11-21},
	journal = {Journal of Hydrology},
	author = {Wilcox, Catherine and Vischel, Théo and Panthou, Gérémy and Bodian, Ansoumana and Blanchet, Juliette and Descroix, Luc and Quantin, Guillaume and Cassé, Claire and Tanimoun, Bachir and Kone, Soungalo},
	month = nov,
	year = {2018},
	keywords = {West Africa, extreme rainfall, AMMA-CATCH, IGE, Extreme values, Flood hazard, Floods, Model selection, Non-stationarity, AO, PHYREV, extreme runoff, sahel},
	pages = {531--545},
}

@article{nkrumah_recent_2019,
	title = {Recent {Trends} in the {Daily} {Rainfall} {Regime} in {Southern} {West} {Africa}},
	volume = {10},
	issn = {2073-4433},
	url = {https://www.mdpi.com/2073-4433/10/12/741},
	doi = {10.3390/atmos10120741},
	abstract = {Extreme climate events, either being linked to dry spells or extreme precipitation, are of major concern in Africa, a region in which the economy and population are highly vulnerable to climate hazards. However, recent trends in climate events are not often documented in this poorly surveyed continent. This study makes use of a large set of daily rain gauge data covering Southern West Africa (extending from 10° W to 10° E and from 4° N to 12° N) from 1950 to 2014. The evolution of the number and the intensity of daily rainfall events, especially the most extremes, were analyzed at the annual and seasonal scales. During the first rainy season (April–July), mean annual rainfall is observed to have a minor trend due to less frequent but more intense rainfall mainly along the coast of Southern West Africa (SWA) over the last two decades. The north–south seasonal changes exhibit an increase in mean annual rainfall over the last decade during the second rainy season (September–November) linked by both an increase in the frequency of occurrence of rainy days as well as an increase in the mean intensity and extreme events over the last decade. The study also provides evidence of a disparity that exists between the west and east of SWA, with the east recording a stronger increase in the mean intensity of wet days and extreme rainfall during the second rainy season (September–November).},
	language = {en},
	number = {12},
	urldate = {2019-11-29},
	journal = {Atmosphere},
	author = {Nkrumah, Francis and Vischel, Théo and Panthou, Geremy and Klutse, Nana Ama Browne and Adukpo, David C. and Diedhiou, Arona},
	month = nov,
	year = {2019},
	keywords = {AMMA-CATCH, climat soudanien},
	pages = {741},
}

@article{fisher_ecostress_2020,
	title = {{ECOSTRESS}: {NASA}'s next generation mission to measure evapotranspiration from the {International} {Space} {Station}},
	volume = {56},
	issn = {0043-1397},
	shorttitle = {{ECOSTRESS}},
	url = {http://doi.wiley.com/10.1029/2019WR026058},
	doi = {10.1029/2019WR026058},
	abstract = {Abstract The ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) was launched to the International Space Station on 29 June 2018 by the National Aeronautics and Space Administration (NASA). The primary science focus of ECOSTRESS is centered on evapotranspiration (ET), which is produced as Level-3 (L3) latent heat flux (LE) data products. These data are generated from the Level-2 land surface temperature and emissivity product (L2\_LSTE), in conjunction with ancillary surface and atmospheric data. Here, we provide the first validation (Stage 1, preliminary) of the global ECOSTRESS clear-sky ET product (L3\_ET\_PT-JPL, Version 6.0) against LE measurements at 82 eddy covariance sites around the world. Overall, the ECOSTRESS ET product performs well against the site measurements (clear-sky instantaneous/time of overpass: r2 = 0.88; overall bias = 8\%; normalized root-mean-square error, RMSE = 6\%). ET uncertainty was generally consistent across climate zones, biome types, and times of day (ECOSTRESS samples the diurnal cycle), though temperate sites are overrepresented. The 70-m-high spatial resolution of ECOSTRESS improved correlations by 85\%, and RMSE by 62\%, relative to 1-km pixels. This paper serves as a reference for the ECOSTRESS L3 ET accuracy and Stage 1 validation status for subsequent science that follows using these data.},
	language = {en},
	number = {4},
	urldate = {2020-04-08},
	journal = {Water Resources Research},
	author = {Fisher, Joshua B. and Lee, Brian and Purdy, Adam J. and Halverson, Gregory H. and Dohlen, Matthew B. and Cawse-Nicholson, Kerry and Wang, Audrey and Anderson, Ray G. and Aragon, Bruno and Arain, M. Altaf and Baldocchi, Dennis D. and Baker, John M. and Barral, Hélène and Bernacchi, Carl J. and Bernhofer, Christian and Biraud, Sébastien C. and Bohrer, Gil and Brunsell, Nathaniel and Cappelaere, Bernard and Castro-Contreras, Saulo and Chun, Junghwa and Conrad, Bryan J. and Cremonese, Edoardo and Demarty, Jérôme and Desai, Ankur R. and De Ligne, Anne and Foltýnová, Lenka and Goulden, Michael L. and Griffis, Timothy J. and Grünwald, Thomas and Johnson, Mark S. and Kang, Minseok and Kelbe, Dave and Kowalska, Natalia and Lim, Jong-Hwan and Maïnassara, Ibrahim and McCabe, Matthew F. and Missik, Justine E.C. and Mohanty, Binayak P. and Moore, Caitlin E. and Morillas, Laura and Morrison, Ross and Munger, J. William and Posse, Gabriela and Richardson, Andrew D. and Russell, Eric S. and Ryu, Youngryel and Sanchez-Azofeifa, Arturo and Schmidt, Marius and Schwartz, Efrat and Sharp, Iain and Šigut, Ladislav and Tang, Yao and Hulley, Glynn and Anderson, Martha and Hain, Christopher and French, Andrew and Wood, Eric and Hook, Simon},
	month = apr,
	year = {2020},
	keywords = {AMMA-CATCH, ext1},
	pages = {e2019WR026058},
}

@article{brandt_unexpectedly_2020,
	title = {An unexpectedly large count of trees in the {West} {African} {Sahara} and {Sahel}},
	url = {https://daac.ornl.gov/cgi-bin/dsviewer.pl?ds_id=1832},
	doi = {10.3334/ORNLDAAC/1832},
	abstract = {This data set provides the first 50 cm mapping of trees and bushes outside of forests. Trees in forests have received much attention while trees outside of forests have been ignored. However, recent developments using commercial satellite data at the 50 cm x-y scale coupled with high performance computing and machine learning have enumerated trees outside of forests over more than a million of square kilometers in semi-arid areas in sub-Saharan Africa at the 50 cm scale. This will provide accurate estimates of woody carbon in arid and semi-arid areas throughout the Earth for the first time.},
	language = {en},
	urldate = {2020-10-15},
	journal = {Nature},
	author = {Brandt, M. and Tucker, C.J. and Kariryaa, A. and Rasmussen, K. and Abel, C. and Small, J. and Chave, J. and Rasmussen, L.V. and Hiernaux, P and Diouf, A.A. and Kergoat, L. and Mertz, Ole and Igel, C. and Gieseke, F. and Schoning, J. and Melocik, K. and Meyer, J. and Sinno, S. and Romero, E. and Glennie, E. and Montagu, A. and Dendoncker, M. and Fensholt, R.},
	year = {2020},
	keywords = {AMMA-CATCH, ext1},
	pages = {319048.3164680001 MB},
}

@article{kergoat_influence_2017,
	title = {Influence of dry-season vegetation variability on {Sahelian} dust during 2002-2015: {Dry}-{Season} {Vegetation} and {Sahelian} {Dust}},
	volume = {44},
	issn = {0094-8276},
	shorttitle = {Influence of dry-season vegetation variability on {Sahelian} dust during 2002-2015},
	url = {http://doi.wiley.com/10.1002/2016GL072317},
	doi = {10.1002/2016GL072317},
	abstract = {Abstract The drivers of dust emission interannual variability in North Africa, the largest dust source on Earth, are still debated. Early studies outlined the role of previous-season rainfall and vegetation growth, while some recent studies emphasize the role of wind variability. Here we use a newly developed estimation of dry-season nonphotosynthetic vegetation cover in the Sahel based on Moderate Resolution Imaging Spectroradiometer (MODIS) short-wave infrared bands over the 2002–2015 period. The vegetation growth anomalies caused by variability of rainfall in June–September translate to anomalies of dry vegetation cover that persist throughout the dry season until May. These vegetation anomalies explain 43\% (50\%) of the year-to-year variance in Sahelian-mean dry-season aerosol optical depth (AOD) as derived from MODIS Deep Blue (Sun photometers). Similar explained variance is found with 10 m wind speed and dust uplift potential. The central Sahel proves more important than the western Sahel for dry-season AOD variability.},
	language = {en},
	number = {10},
	urldate = {2020-10-22},
	journal = {Geophysical Research Letters},
	author = {Kergoat, L. and Guichard, F. and Pierre, C. and Vassal, C.},
	month = may,
	year = {2017},
	keywords = {AMMA-CATCH},
	pages = {5231--5239},
}

@article{chu_fluxes_2017,
	title = {Fluxes all of the time? {A} primer on the temporal representativeness of {FLUXNET}: {FLUXES} {ALL} {OF} {THE} {TIME}?},
	volume = {122},
	issn = {2169-8953},
	shorttitle = {Fluxes all of the time?},
	url = {http://doi.wiley.com/10.1002/2016JG003576},
	doi = {10.1002/2016JG003576},
	abstract = {Abstract FLUXNET, the global network of eddy covariance flux towers, provides the largest synthesized data set of CO2, H2O, and energy fluxes. To achieve the ultimate goal of providing flux information “everywhere and all of the time,” studies have attempted to address the representativeness issue, i.e., whether measurements taken in a set of given locations and measurement periods can be extrapolated to a space- and time-explicit extent (e.g., terrestrial globe, 1982–2013 climatological baseline). This study focuses on the temporal representativeness of FLUXNET and tests whether site-specific measurement periods are sufficient to capture the natural variability of climatological and biological conditions. FLUXNET is unevenly representative across sites in terms of the measurement lengths and potentials of extrapolation in time. Similarity of driver conditions among years generally enables the extrapolation of flux information beyond measurement periods. Yet such extrapolation potentials are further constrained by site-specific variability of driver conditions. Several driver variables such as air temperature, diurnal temperature range, potential evapotranspiration, and normalized difference vegetation index had detectable trends and/or breakpoints within the baseline period, and flux measurements generally covered similar and biased conditions in those drivers. About 38\% and 60\% of FLUXNET sites adequately sampled the mean conditions and interannual variability of all driver conditions, respectively. For long-record sites (≥15 years) the percentages increased to 59\% and 69\%, respectively. However, the justification of temporal representativeness should not rely solely on the lengths of measurements. Whenever possible, site-specific consideration (e.g., trend, breakpoint, and interannual variability in drivers) should be taken into account.},
	language = {en},
	number = {2},
	urldate = {2022-06-30},
	journal = {Journal of Geophysical Research: Biogeosciences},
	author = {Chu, Housen and Baldocchi, Dennis D. and John, Ranjeet and Wolf, Sebastian and Reichstein, Markus},
	month = feb,
	year = {2017},
	keywords = {AMMA-CATCH},
	pages = {289--307},
}

@article{yao_long_2021,
	title = {A long term global daily soil moisture dataset derived from {AMSR}-{E} and {AMSR2} (2002–2019)},
	volume = {8},
	issn = {2052-4463},
	url = {http://www.nature.com/articles/s41597-021-00925-8},
	doi = {10.1038/s41597-021-00925-8},
	abstract = {Abstract Long term surface soil moisture (SSM) data with stable and consistent quality are critical for global environment and climate change monitoring. L band radiometers onboard the recently launched Soil Moisture Active Passive (SMAP) Mission can provide the state-of-the-art accuracy SSM, while Advanced Microwave Scanning Radiometer for EOS (AMSR-E) and AMSR2 series provide long term observational records of multi-frequency radiometers (C, X, and K bands). This study transfers the merits of SMAP to AMSR-E/2, and develops a global daily SSM dataset (named as NNsm) with stable and consistent quality at a 36 km resolution (2002–2019). The NNsm can reproduce the SMAP SSM accurately, with a global Root Mean Square Error (RMSE) of 0.029 m 3 /m 3 . NNsm also compares well with in situ SSM observations, and outperforms AMSR-E/2 standard SSM products from JAXA and LPRM. This global observation-driven dataset spans nearly two decades at present, and is extendable through the ongoing AMSR2 and upcoming AMSR3 missions for long-term studies of climate extremes, trends, and decadal variability.},
	language = {en},
	number = {1},
	urldate = {2022-10-25},
	journal = {Scientific Data},
	author = {Yao, Panpan and Lu, Hui and Shi, Jiancheng and Zhao, Tianjie and Yang, Kun and Cosh, Michael H. and Gianotti, Daniel J. Short and Entekhabi, Dara},
	month = dec,
	year = {2021},
	keywords = {AMMA-CATCH, extérieur, ISMN},
	pages = {143},
}

@article{duku_impacts_2018,
	title = {Impacts of climate change on cropping patterns in a tropical, sub-humid watershed},
	volume = {13},
	issn = {1932-6203},
	url = {https://dx.plos.org/10.1371/journal.pone.0192642},
	doi = {10.1371/journal.pone.0192642},
	language = {en},
	number = {3},
	urldate = {2022-10-25},
	journal = {PLOS ONE},
	author = {Duku, Confidence and Zwart, Sander J. and Hein, Lars},
	editor = {Subudhi, Prasanta K.},
	month = mar,
	year = {2018},
	keywords = {AMMA-CATCH, ACLN, Benin, extérieur, Oueme},
	pages = {e0192642},
}

@article{jambou_malaria_2022,
	title = {Malaria {Transmission} in {Sahelian} {African} {Regions}, a {Witness} of {Climate} {Changes}},
	volume = {19},
	issn = {1660-4601},
	doi = {10.3390/ijerph191610105},
	abstract = {Climate changes in the eastern part of Sahelian regions will induce an increase in rainfalls and extreme climate events. In this area, due to the intense events and floods, malaria transmission, a climate sensitive disease, is thus slowly extending in time to the drought season and in areas close to the border of the desert. Vectors can as well modify their area of breeding. Control programs must be aware of these changes to adapt their strategies.},
	number = {16},
	journal = {INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH},
	author = {Jambou, R and Njedanoun, M and Panthou, G and Descroix, L},
	month = aug,
	year = {2022},
}

@article{lo_dry_2022,
	title = {Dry season forage assessment across senegalese rangelands using earth observation data},
	volume = {10},
	issn = {2296-665X},
	doi = {10.3389/fenvs.2022.931299},
	abstract = {Strengthening of feed security in the Sahel is urgently needed given the climate change and growing human population. A prerequisite to this is sustainable use of rangeland forage resources for livestock. Many studies have focused on the assessment of rangeland resources during the rainy season, while only a few have focused on the dry season which is the longest and most demanding period for livestock in Sahelian rangelands. The objective of this study is to develop remote sensing-based models for estimating dry season forage vegetation mass. To that end, 29 vegetation indices calculated from each of the MODIS-MCD43A4 (500 m), Landsat-8 (30 m), and Sentinel-2 (10 m) satellite products were used and tested against in situ data collected during three field-measurement campaigns in 2021 at eleven monitoring sites across Senegalese rangelands. Four statistical models were tested, namely, random forest, gradient boosting machines, and simple linear and multiple linear regressions. The two main vegetation mass variables modeled from remote sensing imagery were the standing herbaceous and litter dry mass (BH) and total forage dry mass (BT) with a dry mass of woody plant leaves added to BH. Overall, Sentinel-2 data provided the best performance for the assessment of BH with multiple linear regression (R-2 = 0.74; RMSE = 378 kg DM/ha) using NDI5 (Normalized Difference Index5), GRCI (Green Residue Cover Index), SRI (Simple Ratio Index), TCARI (Transformed Chlorophyll Absorption in Reflectance Index), and DFI (Dead Fuel Index) indices. For BT, the best model was also obtained from Sentinel-2 data, including RVI3 (Ratio Vegetation Index3) (R-2 = 0.78; RMSE = 496 kg DM/ha). Results showed the suitability of combining the red, green, blue, NIR, SWIR1, and SWIR2 bands in monitoring forage availability during the dry season. Our study revealed that the spectral richness of the optical sensor systems Sentinel-2, Landsat-8, and MODIS-MCD43A4 allowed for accurate assessments of dry-season forage mass of semi-arid rangelands. Adding to this, the high spatial and temporal resolution of Sentinel-2 satellite imagery makes this a promising data source for timely monitoring. These findings can support the monitoring of the animal feed balance in Sahelian countries and contribute to enhancing the resilience of pastoralism toward feed shortage through early warning systems.},
	journal = {FRONTIERS IN ENVIRONMENTAL SCIENCE},
	author = {Lo, A and Diouf, AA and Diedhiou, I and Bassene, CDE and Leroux, L and Tagesson, T and Fensholt, R and Hiernaux, P and Mottet, A and Taugourdeau, S and Ngom, D and Toure, I and Ndao, B and Sarr, MA},
	month = sep,
	year = {2022},
}

@article{tucker_sub-continental-scale_2023,
	title = {Sub-continental-scale carbon stocks of individual trees in {African} drylands},
	volume = {615},
	issn = {1476-4687},
	url = {https://doi.org/10.1038/s41586-022-05653-6},
	doi = {10.1038/s41586-022-05653-6},
	abstract = {The distribution of dryland trees and their density, cover, size, mass and carbon content are not well known at sub-continental to continental scales1–14. This information is important for ecological protection, carbon accounting, climate mitigation and restoration efforts of dryland ecosystems15–18. We assessed more than 9.9 billion trees derived from more than 300,000 satellite images, covering semi-arid sub-Saharan Africa north of the Equator. We attributed wood, foliage and root carbon to every tree in the 0–1,000 mm year−1 rainfall zone by coupling field data19, machine learning20–22, satellite data and high-performance computing. Average carbon stocks of individual trees ranged from 0.54 Mg C ha−1 and 63 kg C tree−1 in the arid zone to 3.7 Mg C ha−1 and 98 kg tree−1 in the sub-humid zone. Overall, we estimated the total carbon for our study area to be 0.84 (±19.8\%) Pg C. Comparisons with 14 previous TRENDY numerical simulation studies23 for our area found that the density and carbon stocks of scattered trees have been underestimated by three models and overestimated by 11 models, respectively. This benchmarking can help understand the carbon cycle and address concerns about land degradation24–29. We make available a linked database of wood mass, foliage mass, root mass and carbon stock of each tree for scientists, policymakers, dryland-restoration practitioners and farmers, who can use it to estimate farmland tree carbon stocks from tablets or laptops.},
	number = {7950},
	journal = {Nature},
	author = {Tucker, Compton and Brandt, Martin and Hiernaux, Pierre and Kariryaa, Ankit and Rasmussen, Kjeld and Small, Jennifer and Igel, Christian and Reiner, Florian and Melocik, Katherine and Meyer, Jesse and Sinno, Scott and Romero, Eric and Glennie, Erin and Fitts, Yasmin and Morin, August and Pinzon, Jorge and McClain, Devin and Morin, Paul and Porter, Claire and Loeffler, Shane and Kergoat, Laurent and Issoufou, Bil-Assanou and Savadogo, Patrice and Wigneron, Jean-Pierre and Poulter, Benjamin and Ciais, Philippe and Kaufmann, Robert and Myneni, Ranga and Saatchi, Sassan and Fensholt, Rasmus},
	month = mar,
	year = {2023},
	pages = {80--86},
}

@article{doumounia_rainfall_2014,
	title = {Rainfall monitoring based on microwave links from cellular telecommunication networks: {First} results from a {West} {African} test bed},
	volume = {41},
	issn = {0094-8276},
	shorttitle = {Rainfall monitoring based on microwave links from cellular telecommunication networks},
	url = {https://doi.org/10.1002/2014GL060724},
	doi = {10.1002/2014GL060724},
	abstract = {Abstract Rainfall monitoring based on commercial terrestrial microwave links is tested for the first time in Burkina Faso, in Sahelian West Africa. In collaboration with one national cellular phone operator, Telecel Faso, the attenuation on a 29?km long microwave link operating at 7?GHz was monitored at 1?s time rate for the monsoon season 2012. The time series of attenuation is transformed into rain rates and compared with rain gauge data. The method is successful in quantifying rainfall: 95\% of the rainy days are detected. The correlation with the daily rain gauge series is 0.8, and the season bias is 6\%. The correlation at the 5?min time step within each event is also high. These results demonstrate the potential interest of exploiting national and regional wireless telecommunication networks for monitoring rainfall in Africa, where operational rain gauge networks are degrading and the hydrometeorological risk increasing.},
	language = {en},
	number = {16},
	urldate = {2023-06-17},
	journal = {Geophysical Research Letters},
	author = {Doumounia, Ali and Gosset, Marielle and Cazenave, Frederic and Kacou, Modeste and Zougmore, François},
	month = aug,
	year = {2014},
	note = {Publisher: John Wiley \& Sons, Ltd},
	keywords = {Africa, Sahel, 1854 Precipitation, 3374 Tropical meteorology, 1840 Hydrometeorology, AMMA-CATCH, IGE, 1848 Monitoring networks, 3394 Instruments and techniques, convective rainfall, hydrometeorology, microwave links, RainCell Africal, rainfall monitoring},
	pages = {6016--6022},
}

@article{bodjrenou_evaluation_2023,
	title = {Evaluation of {Reanalysis} {Estimates} of {Precipitation}, {Radiation}, and {Temperature} over {Benin} ({West} {Africa})},
	volume = {62},
	url = {https://journals.ametsoc.org/view/journals/apme/62/8/JAMC-D-21-0222.1.xml},
	doi = {10.1175/JAMC-D-21-0222.1},
	language = {English},
	number = {8},
	journal = {Journal of Applied Meteorology and Climatology},
	author = {Bodjrenou, René and Cohard, Jean-Martial and Hector, Basile and Lawin, Emmanuel Agnidé and Chagnaud, Guillaume and Danso, Derrick Kwadwo and N’tcha M’po, Yekambessoun and Badou, Félicien and Ahamide, Bernard},
	month = aug,
	year = {2023},
	note = {Place: Boston MA, USA
Publisher: American Meteorological Society},
	pages = {1005--1022},
}

@article{lamboni_variability_2019,
	title = {Variability of {Future} {Rainfall} over the {Mono} {River} {Basin} of {West}-{Africa}},
	volume = {08},
	issn = {2167-9495, 2167-9509},
	url = {http://www.scirp.org/journal/doi.aspx?DOI=10.4236/ajcc.2019.81008},
	doi = {10.4236/ajcc.2019.81008},
	number = {01},
	urldate = {2020-01-23},
	journal = {American Journal of Climate Change},
	author = {Lamboni, Batablinlè and Emmanuel, Lawin Agnidé and Manirakiza, Celestin and Djibib, Zakari Moussa},
	year = {2019},
	keywords = {LMI REZOC},
	pages = {137--155},
}

@article{tchouta_contribution_2019,
	title = {Contribution of time domain electromagnetic and magnetic resonance soundings to groundwater assessment at the margin of lake chad basin, cameroon},
	volume = {170},
	issn = {0926-9851},
	url = {http://www.sciencedirect.com/science/article/pii/S0926985118309200},
	doi = {10.1016/j.jappgeo.2019.103840},
	abstract = {At the edge of a semi-arid sedimentary basin, the Piedmont plain of the Mandara mountains is potentially a key area for the recharge of the Lake Chad Quaternary aquifer. We conducted two geophysical surveys based on magnetic resonance sounding (MRS) and Time-Domain Electromagnetism (TDEM) techniques for a better understanding of the aquifer structure at the piedmont scale in aim to identify preferential groundwater recharge pathways. MRS water content and electrical resistivity of the medium confirmed the very heterogeneous and clayey nature of the quaternary aquifer, limiting the recharge to the sandiest areas. Thanks to the geophysical methods, these areas have been highlighted near temporary rivers and upstream of the study area near Maroua city. Because of the thickening of the aquifer downstream, the most transmissive zones are in the mid-slope of the piedmont. The geographical distribution of aquifer properties defined by geophysics and the range of MRS water content (from {\textbackslash}textless2\% to 26\%) may be used in the future to constrain groundwater modelling and specify the recharge of the quaternary aquifer at mountain front.},
	language = {en},
	urldate = {2020-12-01},
	journal = {Journal of Applied Geophysics},
	author = {Tchouta, Kemgang Dongmo and Marie, Boucher and Emmanuel, Mvondo Valentin Yvan and Guillaume, Favreau and Benjamin, Ngounou Ngatcha and Nicaise, Yalo and Baba, Goni Ibrahim and Anatoly, Legchenko},
	month = nov,
	year = {2019},
	keywords = {LMI REZOC, Groundwater resources, Lake Chad Basin, Cameroun, Mountain front recharge, Piedmont aquifer, Semi-arid climate, TDEM / MRS, West and Central Africa},
	pages = {103840},
}

@article{attogouinon_evaluation_2020,
	title = {Evaluation of {General} {Circulation} {Models} over the {Upper} {Ouémé} {River} {Basin} in the {Republic} of {Benin}},
	volume = {7},
	issn = {2306-5338},
	url = {https://www.mdpi.com/2306-5338/7/1/11},
	doi = {10.3390/hydrology7010011},
	abstract = {This study assessed the performance of eight general circulation models (GCMs) implemented in the upper Ouémé River basin in Benin Republic (West Africa) during the Fifth Assessment Report on Climate Change. Historical rainfall simulations of the climate model of Rossby Regional Centre (RCA4) driven by eight Coupled Model Intercomparison Project (CMIP5) GCMs over a 55-year period (1951 to 2005) are evaluated using the observational data set. Apart from daily rainfall, other rainfall parameters calculated from observed and simulated rainfall were compared. U-test and other statistical criteria (R2, MBE, MAE, RMSE and standard of standard deviations) were used. According to the results, the simulations correctly reproduce the interannual variability of precipitation in the upper Ouémé River basin. However, the models tend to produce drizzle. Especially, the overestimation of April, May and November rains not only explains the overestimation of seasonal and annual cumulative rainfall but also the early onset of the rainy season and its late withdrawal. However, we noted that this overestimation magnitude varies from one model to another. As for extreme rainfall indices, the models reproduced them poorly. The CanESM2, CNRM-CM5 and EC-EARTH models perform well for daily rainfall. A trade-off is formulated to select the common MPI-ESM-LR, GFDL-ESM2M, NorESM1-M and CanESM2 models for different rainfall parameters for the reliable projection of rainfall in the area. However, the MPI-ESM-LR model is a valuable tool for studying future climate change.},
	language = {en},
	number = {1},
	urldate = {2020-12-01},
	journal = {Hydrology},
	author = {Attogouinon, André and Lawin, Agnidé E. and Deliège, Jean-François},
	month = feb,
	year = {2020},
	keywords = {LMI REZOC},
	pages = {11},
}

@article{lawin_statistical_2019,
	title = {Statistical {Analysis} of {Recent} and {Future} {Rainfall} and {Temperature} {Variability} in the {Mono} {River} {Watershed} ({Benin}, {Togo})},
	volume = {7},
	issn = {2225-1154},
	url = {https://www.mdpi.com/2225-1154/7/1/8},
	doi = {10.3390/cli7010008},
	abstract = {This paper assessed the current and mid-century trends in rainfall and temperature over the Mono River watershed. It considered observation data for the period 1981–2010 and projection data from the regional climate model (RCM), REMO, for the period 2018–2050 under emission scenarios RCP4.5 and RCP8.5. Rainfall data were interpolated using ordinary kriging. Mann-Kendall, Pettitt and Standardized Normal Homogeneity (SNH) tests were used for trends and break-points detection. Rainfall interannual variability analysis was based on standardized precipitation index (SPI), whereas anomalies indices were considered for temperature. Results revealed that on an annual scale and all over the watershed, temperature and rainfall showed an increasing trend during the observation period. By 2050, both scenarios projected an increase in temperature compared to the baseline period 1981–2010, whereas annual rainfall will be characterized by high variabilities. Rainfall seasonal cycle is expected to change in the watershed: In the south, the second rainfall peak, which usually occurs in September, will be extended to October with a higher value. In the central and northern parts, rainfall regime is projected to be characterized by late onsets, a peak in September and lower precipitation until June and higher thereafter. The highest increase and decrease in monthly precipitation are expected in the northern part of the watershed. Therefore, identifying relevant adaptation strategies is recommended.},
	language = {en},
	number = {1},
	urldate = {2020-12-01},
	journal = {Climate},
	author = {Lawin, Agnidé E. and Hounguè, Nina and Biaou, Chabi and Badou, Djigbo},
	month = jan,
	year = {2019},
	keywords = {LMI REZOC, Benin, Togo},
	pages = {8},
}

@article{ouermi_comparison_2019,
	title = {Comparison of hydrological models for use in climate change studies: {A} test on 241 catchments in {West} and {Central} {Africa}},
	volume = {351},
	issn = {1631-0713},
	shorttitle = {Comparison of hydrological models for use in climate change studies},
	url = {http://www.sciencedirect.com/science/article/pii/S163107131930104X},
	doi = {10.1016/j.crte.2019.08.001},
	abstract = {The present work reports on the study and the comparison of the performance of three “Génie rural” (GR) and two Water Balance (WB) models. The calibration and robustness performances are analysed in the light of the hydro-climatic conditions. The study shows that the GR models are much more efficient and robust than the WB models. The behaviour of calibration performance as a function of hydroclimatic variables varies according to the model and goodness-of-fit criteria (GOFC). The GR models are more robust in terms of NSE(Q) and NSE(√Q) and the WB models in terms of KGE. For more robustness of the models, it is better to transfer the parameters to wetter periods or periods with a lower Potential EvapoTranspiration (PET) than the calibration period. For a loss of robustness of less than 20\% for GR and 30\% for WB, the variation between calibration and rain validation/PET periods must be around ±15\%/±1.5\%.},
	language = {en},
	number = {7},
	urldate = {2020-12-01},
	journal = {Comptes Rendus Geoscience},
	author = {Ouermi, Kiswendsida Samiratou and Paturel, Jean-Emmanuel and Adounpke, Julien and Lawin, Agnidé Emmanuel and Goula, Bi Tié Albert and Amoussou, Ernest},
	month = oct,
	year = {2019},
	keywords = {Climate change, LMI REZOC, Rainfall-runoff modelling, West and Central Africa, Model calibration, Model robustness},
	pages = {477--486},
}

@article{houemenou_degradation_2020,
	title = {Degradation of groundwater quality in expanding cities in {West} {Africa}. {A} case study of the unregulated shallow aquifer in {Cotonou}},
	volume = {582},
	issn = {00221694},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0022169419311734},
	doi = {10.1016/j.jhydrol.2019.124438},
	language = {en},
	urldate = {2020-12-07},
	journal = {Journal of Hydrology},
	author = {Houéménou, Honoré and Tweed, Sarah and Dobigny, Gauthier and Mama, Daouda and Alassane, Abdoukarim and Silmer, Roland and Babic, Milanka and Ruy, Stéphane and Chaigneau, Alexis and Gauthier, Philippe and Socohou, Akilou and Dossou, Henri-Joël and Badou, Sylvestre and Leblanc, Marc},
	month = mar,
	year = {2020},
	keywords = {LMI REZOC},
	pages = {124438},
}

@article{karim_factors_2019,
	title = {Factors influencing the partitioning of metal residues (lead) in {Nokoué} {Lake} ({Benin})},
	url = {https://www.elixirpublishers.com/index.php?route=articles/category&path=346_297},
	number = {126},
	journal = {Elixir Aquaculture},
	author = {Karim, A.Y.A and Saizonou, M.K. and Gbaguidi, M.A.N. and Azokpota, E. and Dovonon, L.F. and Mama, D. and Soclo, H.H.},
	year = {2019},
	keywords = {LMI REZOC, predatory journal},
	pages = {2438--52444},
}

@article{davies_variability_2023,
	title = {Variability in {Surface} {Radiative} {Fluxes} over {West} {Africa} using {Wavelet} and {Principal} {Component} {Analyses}},
	shorttitle = {{JASTP}},
	url = {https://www.sciencedirect.com/journal/journal-of-atmospheric-and-solar-terrestrial-physics},
	language = {English},
	journal = {Journal of Atmospheric and Solar-Terrestrial Physics},
	author = {Davies, P. and Mamadou, O. and Quansah, E. and Aryee, J.N.A. and Atiah, W.A. and Amekudzi, L.K. and Sam, F. and Galle, S. and Demarty, J.},
	month = apr,
	year = {2023},
	keywords = {AMMA-CATCH, LMI REZOC},
	pages = {JASTP--D--23--00103},
}

@article{yarou_extreme_2021,
	title = {Extreme {Temperature} {Trends} in the {Beninese} {Niger} {River} {Basin} ({Benin})},
	volume = {10},
	issn = {2167-9495, 2167-9509},
	url = {https://www.scirp.org/journal/doi.aspx?doi=10.4236/ajcc.2021.104018},
	doi = {10.4236/ajcc.2021.104018},
	number = {04},
	urldate = {2021-11-23},
	journal = {American Journal of Climate Change},
	author = {Yarou, Halissou and Alamou, Eric and Obada, Ezechiel and Biao, Ibukun Eliezer},
	year = {2021},
	keywords = {LMI REZOC},
	pages = {371--385},
}

@article{yarou_variabilite_2019,
	title = {Variabilité des extrêmes pluviométriques récents dans le bassin béninois du fleuve {Niger} (1960-2016), {Bénin}},
	volume = {34},
	issn = {1813-3290},
	url = {https://revist.net/sommaire_34.php},
	language = {Français},
	journal = {Revue Ivoirienne des Sciences et Technologie (REVIST)},
	author = {Yarou, Halissou and Obada, Ezechiel and Biao, Ibukun Eliezer and Badou, Djigbo Félicien and Alamou, Eric},
	year = {2019},
	keywords = {LMI REZOC},
	pages = {112--126},
}

@article{anwar_influence_2021,
	title = {On the {Influence} of {Vegetation} {Cover} {Changes} and {Vegetation}-{Runoff} {Systems} on the {Simulated} {Summer} {Potential} {Evapotranspiration} of {Tropical} {Africa} {Using} {RegCM4}},
	volume = {5},
	issn = {2509-9426, 2509-9434},
	url = {https://link.springer.com/10.1007/s41748-021-00252-3},
	doi = {10.1007/s41748-021-00252-3},
	abstract = {Abstract The community land model version 4.5 provides two ways for treating the vegetation cover changes (a static versus an interactive) and two runoff schemes for tracking the soil moisture changes. In this study, we examined the sensitivity of the simulated boreal summer potential evapotranspiration (PET) to the aforementioned options using a regional climate model. Three different experiments with each one covering 16 years have been performed. The two runoff schemes were designated as SIMTOP (TOP) and variable infiltration capacity (VIC). Both runoff schemes were coupled to the carbon–nitrogen (CN) module, thus the vegetation status can be influenced by soil moisture changes. Results show that vegetation cover changes alone affect considerably the simulated 2-m mean air temperature (T2M). However, they do not affect the global incident solar radiation (RSDS) and PET. Conversely to the vegetation cover changes alone, the vegetation-runoff systems affect both the T2M and RSDS. Therefore, they considerably affect the simulated PET. Also, the CN-VIC overestimates the PET more than the CN-TOP compared to the Climatic Research Unit observational dataset. In comparison with the static vegetation case and CN-VIC, the CN-TOP shows the least bias of the simulated PET. Overall, our results show that the vegetation-runoff system is relevant in constraining the PET, though the CN-TOP can be recommended for future studies concerning the PET of tropical Africa.},
	language = {en},
	number = {4},
	urldate = {2021-11-25},
	journal = {Earth Systems and Environment},
	author = {Anwar, Samy A. and Mamadou, Ossénatou and Diallo, Ismaila and Sylla, Mouhamadou Bamba},
	month = dec,
	year = {2021},
	keywords = {LMI REZOC},
	pages = {883--897},
}

@article{hounkpe_assessment_2021,
	title = {Assessment of flood discharge sensitivity to climate indexes in {West} {Africa}},
	volume = {384},
	issn = {2199-899X},
	url = {https://piahs.copernicus.org/articles/384/219/2021/},
	doi = {10.5194/piahs-384-219-2021},
	abstract = {Abstract. Floods are natural disasters that widely affect people and goods. Its frequency and magnitude are projected to substantially increase due to the ongoing environmental change. At regional and national levels, some efforts have been made in predicting floods at a short-term range. However, the usefulness of flood prediction increases as the time lead increases. The objective of this work is therefore to investigate flood sensitivity to climate indexes in West Africa as a basis for seasonal flood forecasting. The methodology consists of optimizing the relationship between Annual Maximal Discharge (AMD), a proxy for flood discharge and various climate indexes using correlation coefficient, linear regression and statistical modeling based on 56 river gauging stations across West Africa. The climate indexes considered are the Sea Surface Temperature (SST) of the Tropical Northern Atlantic (TNA), SST of the Tropical Southern Atlantic (TSA), the Sea Level Pressure (SLP) of the Southern Oscillation Indexes (SOI) and the detrended El-Nino Southern Oscillation indexes. It was found that SOI/SLP indexes are the most strongly related to the AMD for the investigated stations with generally high, positive, and statistically significant correlation. The TSA/SST indexes indicated both positive and negative statistically significant correlations with river discharge in the region. The percentage change in AMD per unit change in SOI/SLP for most of the statistically significant stations is within 10 \% and 50 \% indicating a strong relationship between these two variables. This relationship could serve as a basis for seasonal flood forecasting in the study area.},
	language = {en},
	urldate = {2021-12-08},
	journal = {Proceedings of the International Association of Hydrological Sciences},
	author = {Hounkpè, Jean and Badou, Djigbo F. and Bossa, Aymar Y. and Yira, Yacouba and Adounkpè, Julien and Alamou, Eric A. and Lawin, Emmanuel A. and Sintondji, Luc O. C. and Afouda, Abel A. and Amoussou, Ernest},
	month = nov,
	year = {2021},
	keywords = {LMI REZOC},
	pages = {219--224},
}

@article{hounkpe_potential_2022,
	title = {Potential for seasonal flood forecasting in {West} {Africa} using climate indexes},
	issn = {1753-318X, 1753-318X},
	url = {https://onlinelibrary.wiley.com/doi/10.1111/jfr3.12833},
	doi = {10.1111/jfr3.12833},
	language = {en},
	urldate = {2022-12-07},
	journal = {Journal of Flood Risk Management},
	author = {Hounkpè, Jean and Merz, Bruno and Badou, Félicien D. and Bossa, Aymar Y. and Yira, Yacouba and Lawin, Emmanuel A.},
	month = jul,
	year = {2022},
	keywords = {LMI REZOC},
}

@article{oyerinde_multiscale_2022,
	title = {Multiscale assessments of hydroclimatic modelling uncertainties under a changing climate},
	volume = {13},
	issn = {2040-2244, 2408-9354},
	url = {https://iwaponline.com/jwcc/article/13/3/1534/86338/Multiscale-assessments-of-hydroclimatic-modelling},
	doi = {10.2166/wcc.2022.266},
	abstract = {Abstract Since the 1970s, climate change has led to decreasing water resources in the Sahel. To cope with climate change, reliable modelling of future hydroclimatic evolutions is required. This study uses multiclimate and hydrological modelling approaches to access past and future (1951–2100) hydroclimatic trends on nine headwater catchments of the Niger River Basin. Eight global climate models (GCMs) dynamically downscaled under the CORDEX CMIP5 project were used. The GCM data were bias-corrected with quantile–quantile mapping. Three rainfall–runoff models (IHACRES-CMD, IHACRES-CWI and Sacramento) were calibrated and validated with observed data and used to simulate runoff. The projected future runoff trend from 2061 to 2090 was compared across the three hydrological models to assess uncertainties from hydrological models. Results show that the bias correction positively enhanced the quality of eight GCMs across the nine catchments. An average Nash–Sutcliffe Efficiency (NSE) across the nine catchments was improved from 0.53 to 0.68 and the Kling–Gupta Efficiency (KGE) was enhanced from 0.65 to 0.83. The three hydrological models were calibrated and validated appropriately on the nine catchments. Despite this, high hydrological modelling uncertainties were witnessed with contrasting projected future runoff patterns by the three models. We recommended the use of ensembles of both climate and hydrological models to provide reliable hydroclimatic modelling.},
	language = {en},
	number = {3},
	urldate = {2022-12-07},
	journal = {Journal of Water and Climate Change},
	author = {Oyerinde, Ganiyu Titilope and Lawin, Agnide E. and Anthony, Tobore},
	month = mar,
	year = {2022},
	keywords = {LMI REZOC},
	pages = {1534--1547},
}

@article{chagnaud_capturing_2023,
	title = {Capturing and {Attributing} the {Rainfall} {Regime} {Intensification} in the {West} {African} {Sahel} with {CMIP6} {Models}},
	issn = {0894-8755, 1520-0442},
	url = {https://journals.ametsoc.org/view/journals/clim/aop/JCLI-D-22-0412.1/JCLI-D-22-0412.1.xml},
	doi = {10.1175/JCLI-D-22-0412.1},
	abstract = {Abstract Rainfall in the Sahel is extremely variable on daily to multi-decadal timescales, challenging climate models to realistically simulate its past and future evolution and questioning their relevance for defining suitable climate change adaptation strategies. Improving confidence in climate models may be achieved by i) evaluating their capacity for reproducing observed climatic evolution and ii) attributing these evolution. Moreover, there is a need to consider relevant climatic indicators, from an end-user point of view. Fully-coupled (CMIP6-AOGCM) models with idealized detection and attribution forcings (DAMIP) as well as atmosphere-only simulations (AMIP) are used to investigate the respective roles of external forcing factors and internal climate variability. We show that CMIP6 models contain signs of the intensification of the rainfall regime as detected over the past 35 years from a regional daily observations network. Both the increase in intensity and occurrence of wet days, as well as that of extreme daily rainfall, are remarkably well reproduced by historical simulations incorporating anthropogenic forcing factors, aerosols contributing the largest share of this trend. Though more strongly affected by model structure uncertainty, the greenhouse gases forcing also displays noticeably robust features. Models are shown to fail at simulating realistic dry extreme evolution. These findings give incentive for further investigating the underlying physical mechanisms that drive the sahelian rainfall regime evolution at regional to sub-regional scales. Furthermore, future hydro-climatic trajectories in the Sahel should be explored, though particular caution is required as to which rainfall indicator to consider.},
	urldate = {2023-01-04},
	journal = {Journal of Climate},
	author = {Chagnaud, G and Panthou, G and Vischel, T and Lebel, T},
	year = {2023},
	keywords = {AMMA-CATCH, LMI REZOC},
	pages = {1823--1843},
}

@article{vodounon_drought_2022,
	title = {Drought {Forecasting} in {Alibori} {Department} in {Benin} using the {Standardized} {Precipitation} {Index} and {Machine} {Learning} {Approaches}},
	volume = {13},
	issn = {21565570, 2158107X},
	url = {http://thesai.org/Publications/ViewPaper?Volume=13&Issue=12&Code=IJACSA&SerialNo=113},
	doi = {10.14569/IJACSA.2022.01312113},
	language = {en},
	number = {12},
	urldate = {2023-05-29},
	journal = {International Journal of Advanced Computer Science and Applications},
	author = {Vodounon, Rodrigue B. W. and Soude, Henoc and Mamadou, Ossenatou},
	year = {2022},
	keywords = {LMI REZOC},
}

@article{tchinda_assessing_2022,
	title = {Assessing precipitation seasonal forecasts in {Central} {Africa} using {North} {American} {Multimodel} {Ensemble} ({NMME})},
	volume = {147},
	issn = {0177-798X, 1434-4483},
	url = {https://link.springer.com/10.1007/s00704-021-03915-3},
	doi = {10.1007/s00704-021-03915-3},
	language = {en},
	number = {3-4},
	urldate = {2023-05-29},
	journal = {Theoretical and Applied Climatology},
	author = {Tchinda, Armand Feudjio and Tanessong, Roméo Stève and Mamadou, Ossénatou and Orou, Jean Bio Chabi},
	month = feb,
	year = {2022},
	keywords = {LMI REZOC},
	pages = {1309--1325},
}

@article{tchinda_predictive_2022,
	title = {Predictive skill of {North} {American} {Multi}‐{Model} {Ensemble} seasonal forecasts for the climate rainfall over {Central} {Africa}},
	volume = {29},
	issn = {1350-4827, 1469-8080},
	url = {https://onlinelibrary.wiley.com/doi/10.1002/met.2074},
	doi = {10.1002/met.2074},
	language = {en},
	number = {3},
	urldate = {2023-05-29},
	journal = {Meteorological Applications},
	author = {Tchinda, Armand Feudjio and Tanessong, Roméo Stève and Mamadou, Ossénatou and Tchida Diffo, Vanessa and Djomou Yepdo, Zephirin and Chabi Orou, Jean Bio},
	month = may,
	year = {2022},
	keywords = {LMI REZOC},
}

@article{kotchoni_relationships_2019,
	title = {Relationships between rainfall and groundwater recharge in seasonally humid {Benin}: a comparative analysis of long-term hydrographs in sedimentary and crystalline aquifers},
	volume = {27},
	issn = {1435-0157},
	shorttitle = {Relationships between rainfall and groundwater recharge in seasonally humid {Benin}},
	url = {https://doi.org/10.1007/s10040-018-1806-2},
	doi = {10.1007/s10040-018-1806-2},
	abstract = {Groundwater is a vital source of freshwater throughout the tropics enabling access to safe water for domestic, agricultural and industrial purposes close to the point of demand. The sustainability of groundwater withdrawals is controlled, in part, by groundwater recharge, yet the conversion of rainfall into recharge remains inadequately understood, particularly in the tropics. This study examines a rare set of 19–25-year records of observed groundwater levels and rainfall under humid conditions (mean rainfall is {\textasciitilde}1,200 mm year−1) in three common geological environments of Benin and other parts of West Africa: Quaternary sands, Mio-Pliocene sandstone, and crystalline rocks. Recharge is estimated from groundwater-level fluctuations and employs values of specific yield derived from magnetic resonance soundings. Recharge is observed to occur seasonally and linearly in response to rainfall exceeding an apparent threshold of between 140 and 250 mm year−1. Inter-annual changes in groundwater storage correlate well to inter-annual rainfall variability. However, recharge varies substantially depending upon the geological environment: annual recharge to shallow aquifers of Quaternary sands amounts to as much as 40\% of annual rainfall, whereas in deeper aquifers of Mio-Pliocene sandstone and weathered crystalline rocks, annual fractions of rainfall generating recharge are 13 and 4\%, respectively. Differences are primarily attributed to the thickness of the unsaturated zone and to the lithological controls on the transmission and storage of rain-fed recharge.},
	language = {en},
	number = {2},
	urldate = {2019-04-26},
	journal = {Hydrogeology Journal},
	author = {Kotchoni, D. O. Valerie and Vouillamoz, Jean-Michel and Lawson, Fabrice M. A. and Adjomayi, Philippe and Boukari, Moussa and Taylor, Richard G.},
	month = mar,
	year = {2019},
	keywords = {AMMA-CATCH, LMI REZOC, IGE, Benin, PHYREV, GRIBA},
	pages = {447--457},
}

@article{rashid_evaluation_2019,
	title = {Evaluation of {Groundwater} {Simulations} in {Benin} from the {ALMIP2} {Project}},
	volume = {20},
	issn = {1525-755X, 1525-7541},
	url = {http://journals.ametsoc.org/doi/10.1175/JHM-D-18-0025.1},
	doi = {10.1175/JHM-D-18-0025.1},
	abstract = {A comprehensive estimation of water budget components, particularly groundwater storage (GWS) and fluxes, is crucial. In this study, we evaluate the terrestrial water budget of the Donga basin (Benin, West Africa), as simulated by three land surface models (LSMs) used in the ALMIP2 Project.},
	language = {en},
	number = {2},
	urldate = {2019-05-31},
	journal = {Journal of Hydrometeorology},
	author = {Rashid, Mehnaz and Chien, Rong-You and Ducharne, Agnès and Kim, Hyungjun and Yeh, Pat J.-F. and Peugeot, Christophe and Boone, Aaron and He, Xiaogang and Séguis, Luc and Yabu, Yutaro and Boukari, Moussa and Lo, Min-Hui},
	month = feb,
	year = {2019},
	keywords = {AMMA-CATCH, ext1, LMI REZOC, benin, Almip2},
	pages = {339--354},
}

@article{cuthbert_observed_2019,
	title = {Observed controls on resilience of groundwater to climate variability in sub-{Saharan} {Africa}},
	volume = {572},
	issn = {1476-4687},
	url = {http://www.nature.com/articles/s41586-019-1441-7},
	doi = {10.1038/s41586-019-1441-7},
	abstract = {Groundwater in sub-Saharan Africa supports livelihoods and poverty alleviation1,2, maintains vital ecosystems, and strongly influences terrestrial water and energy budgets3. Yet the hydrological processes that govern groundwater recharge and sustainability—and their sensitivity to climatic variability—are poorly constrained4,5. Given the absence of firm observational constraints, it remains to be seen whether model-based projections of decreased water resources in dry parts of the region4 are justified. Here we show, through analysis of multidecadal groundwater hydrographs across sub-Saharan Africa, that levels of aridity dictate the predominant recharge processes, whereas local hydrogeology influences the type and sensitivity of precipitation–recharge relationships. Recharge in some humid locations varies by as little as five per cent (by coefficient of variation) across a wide range of annual precipitation values. Other regions, by contrast, show roughly linear precipitation–recharge relationships, with precipitation thresholds (of roughly ten millimetres or less per day) governing the initiation of recharge. These thresholds tend to rise as aridity increases, and recharge in drylands is more episodic and increasingly dominated by focused recharge through losses from ephemeral overland flows. Extreme annual recharge is commonly associated with intense rainfall and flooding events, themselves often driven by large-scale climate controls. Intense precipitation, even during years of lower overall precipitation, produces some of the largest years of recharge in some dry subtropical locations. Our results therefore challenge the ‘high certainty’ consensus regarding decreasing water resources4 in such regions of sub-Saharan Africa. The potential resilience of groundwater to climate variability in many areas that is revealed by these precipitation–recharge relationships is essential for informing reliable predictions of climate-change impacts and adaptation strategies.},
	language = {en},
	number = {7768},
	urldate = {2019-08-29},
	journal = {Nature},
	author = {Cuthbert, Mark O. and Taylor, Richard G. and Favreau, Guillaume and Todd, Martin C. and Shamsudduha, Mohammad and Villholth, Karen G. and MacDonald, Alan M. and Scanlon, Bridget R. and Kotchoni, D. O. Valerie and Vouillamoz, Jean-Michel and Lawson, Fabrice M. A. and Adjomayi, Philippe Armand and Kashaigili, Japhet and Seddon, David and Sorensen, James P. R. and Ebrahim, Girma Yimer and Owor, Michael and Nyenje, Philip M. and Nazoumou, Yahaya and Goni, Ibrahim and Ousmane, Boukari Issoufou and Sibanda, Tenant and Ascott, Matthew J. and Macdonald, David M. J. and Agyekum, William and Koussoubé, Youssouf and Wanke, Heike and Kim, Hyungjun and Wada, Yoshihide and Lo, Min-Hui and Oki, Taikan and Kukuric, Neno},
	month = aug,
	year = {2019},
	keywords = {AMMA-CATCH, ext1, LMI REZOC, IGE},
	pages = {230--234},
}

@article{lawin_mid-century_2019,
	title = {Mid-{Century} {Climate} {Change} {Impacts} on {Ouémé} {River} {Discharge} at {Bonou} {Outlet} ({Benin})},
	volume = {6},
	issn = {2306-5338},
	url = {https://www.mdpi.com/2306-5338/6/3/72},
	doi = {10.3390/hydrology6030072},
	abstract = {This work focuses on impacts of climate change on Ouémé River discharge at Bonou outlet based on four global climate models (GCM) over Ouémé catchment from 1971 to 2050. Empirical quantile mapping method is used for bias correction of GCM. Furthermore, twenty-five rain gauges were selected among which are three synoptic stations. The semi-distributed model HEC-HMS (Hydrologic Modeling System from Hydrologic Engineering Center) is used to simulate runoff. As results, HEC-HMS showed ability to simulate runoff while taking into account land use and cover change. In fact, Kling–Gupta Efficiency (KGE) coefficient was 0.94 and 0.91 respectively in calibration and validation. Moreover, Ouémé River discharge is projected to decrease about 6.58 m3/s under Representative Concentration Pathways (RCP 4.5) while an insignificant increasing trend is found under RCP 8.5. Therefore, water resource management infrastructure, especially dam construction, has to be developed for water shortage prevention. In addition, it is essential to account for uncertainties when designing such sensitive infrastructure for flood management.},
	language = {en},
	number = {3},
	urldate = {2020-01-23},
	journal = {Hydrology},
	author = {Lawin, Agnidé Emmanuel and Hounguè, Rita and N’Tcha M’Po, Yèkambèssoun and Hounguè, Nina Rholan and Attogouinon, André and Afouda, Akambi Abel},
	month = aug,
	year = {2019},
	keywords = {LMI REZOC},
	pages = {72},
}

@article{herzog_parametric_2021,
	title = {A parametric sensitivity analysis for prioritizing regolith knowledge needs for modeling water transfers in the {West} {African} critical zone},
	volume = {20},
	issn = {1539-1663, 1539-1663},
	url = {https://onlinelibrary.wiley.com/doi/10.1002/vzj2.20163},
	doi = {10.1002/vzj2.20163},
	language = {en},
	number = {6},
	urldate = {2021-12-20},
	journal = {Vadose Zone Journal},
	author = {Herzog, Amelie and Hector, Basile and Cohard, Jean-Martial and Vouillamoz, Jean‐Michel and Lawson, Fabrice Messan Amene and Peugeot, Christophe and Graaf, Inge},
	month = nov,
	year = {2021},
	keywords = {AMMA-CATCH, LMI REZOC},
}

@article{houngnibo_stochastic_2023,
	title = {Stochastic disaggregation of seasonal precipitation forecasts of the {West} {African} {Regional} {Climate} {Outlook} {Forum}},
	volume = {43},
	issn = {0899-8418},
	url = {https://doi.org/10.1002/joc.8161},
	doi = {10.1002/joc.8161},
	abstract = {Abstract Seasonal rainfall forecasts from the West African Regional Climate Outlook Forum (RCOF) are essential for adapting to climate variability. However, their temporal aggregated nature is a strong limitation, especially when used with impact models requiring daily resolution, such as hydrological or crop models. To address this issue, this study proposes a temporal disaggregation method for these forecasts using in situ data from two districts (Kandi and Parakou) in northern Benin, spanning from 1971 to 2020. A resampling technique was used to construct a daily historical record that aligns with seasonal rainfall forecasts. Three stochastic disaggregation models for rainfall (SRGs) were developed, including two parametric models (SRG1 and SRG2) and one semiparametric (SRG3). Their parameters were estimated from the resampled record to generate daily synthetic data replicating the forecasts. Evaluation of the SRGs revealed that SRG2, which combined a first-order Markov chain with a mixed exponential distribution, performs well in simulating various characteristics of the rainy season, including dry spells, wet spells and daily precipitations. Furthermore, SRG2 maintained the trends of the initial forecasts and outperformed SRG1 and SRG3, as confirmed by the chi-square test. Indeed, a good agreement was observed between the probabilities of the initial prediction and those calculated from the temporal disaggregation with the SRG2 method. Also, for the forecasts expressed by probabilities 15?35?50 and 20?50?30, the cumulative distribution function curves (CDF) of the SRGs exhibited appropriate shifts compared to climatology. These forecasts were specific to the Kandi area in 2008 and 2003, respectively, during the West African RCOFs. Although this study focused specifically on the Kandi and Parakou districts, the temporal disaggregation methodology used can be applied to other locations within West Africa or other RCOFs worldwide. This study offers valuable guidance for generating sector-specific seasonal forecasts for the West African region.},
	number = {12},
	urldate = {2023-11-12},
	journal = {International Journal of Climatology},
	author = {Houngnibo, Mandela Coovi Mahuwètin and Ali, Abdou and Agali, Alhassane and Waongo, Moussa and Lawin, Agnidé Emmanuel and Cohard, Jean-Martial},
	month = oct,
	year = {2023},
	note = {Publisher: John Wiley \& Sons, Ltd},
	keywords = {West Africa, Regional Climate Outlook Forum, seasonal rainfall forecasts, stochastic disaggregation models},
	pages = {5569--5585},
}

@article{agbohessou_what_2023,
	title = {To what extent are greenhouse-gas emissions offset by trees in a {Sahelian} silvopastoral system?},
	volume = {343},
	issn = {0168-1923},
	url = {https://www.sciencedirect.com/science/article/pii/S0168192323004707},
	doi = {10.1016/j.agrformet.2023.109780},
	abstract = {To assess the extent to which trees in a semi-arid silvopastoral system (SPS) can offset the greenhouse-gas (GHG) emissions of the system's livestock, this study used two process-based models (STEP-GENDEC-N2O and DynACof) to simulate 9 years of agricultural activity and resulting emissions in a SPS that has been operating in sahelian Senegal. STEP-GENDEC-N2O simulated soil N2O and CO2 fluxes, plus growth of the herbaceous layer, while DynACof focused on the tree layer. Outputs from the models included simulated time series of vegetative growth, water fluxes, and emissions. This output was validated through the use of published data, and measurements that were made at the SPS. Overall, the outputs from STEP-GENDEC-N2O agreed well with validation data for water fluxes, soil N, soil C, herbaceous biomass, and N2O emissions. Good agreement was also found between the measured fluxes of the SPS ecosystem, and the simulated values that were generated by combining STEP-GENDEC-N2O's simulations (of the herbaceous layer's heterotrophic respiration, autotrophic respiration, and gross primary productivity (GPP)) with DynACof's simulations of the tree layer's autotrophic respiration and GPP. Among the insights gained from the simulations was that in this SPS's sandy soils, nitrification was the dominant process that leads to N2O emissions. Our results show that the trees, at their current density (81 ha−1) offset 18 \% to 41 \% of the GHG emissions from livestock. With further development, the model set-up can be used for estimating the GHG offset at other tree densities, and will be useful for guiding future policies regarding climate-change adaptation and mitigation in the management of the Sahel's SPSs.},
	journal = {Agricultural and Forest Meteorology},
	author = {Agbohessou, Yélognissè and Delon, Claire and Mougin, Eric and Grippa, Manuela and Tagesson, Torbern and Diedhiou, Moussa and Ba, Seydina and Ngom, Daouda and Vezy, Rémi and Ndiaye, Ousmane and Assouma, Mohamed H. and Diawara, Mamadou and Roupsard, Olivier},
	month = dec,
	year = {2023},
	keywords = {Livestock, Greenhouse gas emissions, Process-based model, Silvopastoral systems, Trees},
	pages = {109780},
}

@article{de_fleury_hydrological_2023,
	title = {Hydrological regime of {Sahelian} small waterbodies from combined {Sentinel}-2 {MSI} and {Sentinel}-3 {Synthetic} {Aperture} {Radar} {Altimeter} data},
	volume = {27},
	url = {https://hess.copernicus.org/articles/27/2189/2023/},
	doi = {10.5194/hess-27-2189-2023},
	number = {11},
	journal = {Hydrology and Earth System Sciences},
	author = {de Fleury, M. and Kergoat, L. and Grippa, M.},
	year = {2023},
	pages = {2189--2204},
}

@article{sounmaila_moumouni_impact_2023,
	title = {Impact of integration time steps of rain drop size distribution on their double-moment normalization: a case study in northern {Benin}},
	volume = {355},
	doi = {10.5802/crgeos.200},
	language = {en},
	journal = {Comptes Rendus. Géoscience},
	author = {{Sounmaïla Moumouni} and {Fulgence Payot Akponi} and {Eric-Pascal Zahiri} and {Agnidé Emmanuel Lawin} and {Marielle Gosset}},
	year = {2023},
	note = {Publisher: Académie des sciences, Paris},
	pages = {109--133},
}

@article{koukoui_testing_2023,
	title = {Testing the suitability of {Marginal} {Distribution} {Sampling} as a gap-filling method using some meteorological data from seven sites in {West} {Africa}},
	volume = {30},
	issn = {1350-4827},
	url = {https://doi.org/10.1002/met.2152},
	doi = {10.1002/met.2152},
	abstract = {Abstract Meteorological data are useful in many fields related to climate change studies and their use often requires them to be continuous. To date, marginal distribution sampling (MDS), which consists of filling a missing value with an average of the data that are found in similar meteorological conditions over a flexible time window, is widely adopted in the FLUXNET community. In this work, we evaluate the performance of MDS at diurnal and monthly scales for the incoming shortwave radiation (Swin), relative humidity (RH), vapour pressure deficit (VPD), air and soil temperatures (Tair, Tsoil) acquired across seven sites in West Africa. The criteria tested are the MDS's ability to (i) fill gaps while reducing the error rate, (ii) represent proper variability within data and finally (iii) ensure homogeneity between its output and original data. We found during the daytime that MDS is adequate for filling gaps in Swin when both reducing error rate and a good representation of variability are targeted. If the goal is to have a small error rate, then this approach is recommended for all investigated variables except VPD. During nighttime, MDS is satisfactory to minimize the error when filling gaps in Tair, Tsoil and RH while to represent their variabilities it becomes more sensitive to the rate of missing data. At a monthly scale, the gap-filled data are consistent with the original ones for all variables attributable to data size and a wider sliding window that allows more data under similar conditions to be considered.},
	number = {5},
	urldate = {2023-11-12},
	journal = {Meteorological Applications},
	author = {Koukoui, Djidjoho Renaud Roméo and Mamadou, Ossénatou and Hounsinou, Miriam and Kounouhéwa, Basile},
	month = sep,
	year = {2023},
	note = {Publisher: John Wiley \& Sons, Ltd},
	keywords = {West Africa, artificial gap, continuous data, gap filling, Marginal Distribution Sampling, meteorological data},
	pages = {e2152},
}

@article{hounsinou_turbulence_2023,
	title = {Turbulence {Characteristics} in the {Atmospheric} {Surface} {Layer} {Over} a {Heterogeneous} {Cultivated} {Surface} in a {Tropical} {Region}},
	volume = {188},
	issn = {1573-1472},
	url = {https://doi.org/10.1007/s10546-023-00815-z},
	doi = {10.1007/s10546-023-00815-z},
	abstract = {The description of atmospheric turbulence on heterogeneous surfaces and more specifically during stable stratification conditions, remains nowadays a relevant and open issue in micrometeorology. To partially remedy this problem, we investigate in this study, the behaviour of turbulence above a heterogeneous cultivated surface during stable and unstable conditions. The analyses were realized according to seasons using almost seven years of eddy covariance measurements acquired at 4.95 m height. The results showed that the turbulence kinetic energy per unit mass was on average less than 0.5 m2 s−2 at night but increased during the day. It hits around local noon a peak value {\textasciitilde} 1.6 m2 s−2 on average. The peak value is relatively lower ({\textasciitilde} 0.92 m2 s−2) during the wet season compared to other periods (1.6 m2 s−2). The average value of turbulence intensities are Iu = 0.44, Iv = 0.50 and Iw = 0.22 following u, v, w wind speed directions. During stable conditions, there are turbulent movements when the flux Richardson number is less than a critical value estimated approximately to 0.17. The flux-variance similarity functions that characterize the behaviour of turbulence are seasonally dependent, especially under stable conditions. However, each of these functions obey the Monin–Obukhov Similarity Theory whatever the stratification except those of temperature under near-neutral conditions. The results obtained indicate that the atmospheric turbulence is relative to the type of ecosystem and the height of measurement. This process is led by aerodynamic parameters and wind speed.},
	number = {2},
	journal = {Boundary-Layer Meteorology},
	author = {Hounsinou, Miriam and Mamadou, Ossénatou and Kounouhewa, Basile},
	month = aug,
	year = {2023},
	pages = {321--344},
}

@article{abdou_mahaman_paleochannel_2023,
	title = {Paleochannel groundwater discharge to the {River} {Niger} in the {Iullemmeden} {Basin} estimated by near- surface geophysics and piezometry},
	volume = {82},
	issn = {1866-6299},
	url = {https://doi.org/10.1007/s12665-023-10861-y},
	doi = {10.1007/s12665-023-10861-y},
	abstract = {In drylands, groundwater is often the only perennial source of freshwater to sustain domestic water supplies and irrigation. Knowledge of the pathways and dynamics of groundwater discharge and recharge is, therefore, essential to inform sustainable and rational management of limited water resources. The lower valley of the Dallol Maouri in Niger represents a large fossil tributary (i.e. paleochannel) of the River Niger and drains groundwater regionally from the Iullemmeden Basin through coarse-grained Quaternary sediments. The objective of this paper is to quantify groundwater discharge within this paleochannel using piezometry and near-surface geophysics (TDEM: Time Domain Electromagnetics, MRS: Magnetic Resonance Sounding). TDEM and MRS experiments, conducted at 21 sites along 3 transects, show the thickness of the saturated Quaternary alluvium varies from 7 to 19 m with  estimated effective porosities ranging from 18 to 38\% and a hydraulic conductivity of 0.6–3 ×  10–3 m/s. Dense piezometric surveys along drainage channel reveal hydraulic gradients of 0.2–0.3‰ that generate Darcy fluxes of 1000–2000 m3/day (dry season, i.e. minimum value). Paleochannel discharge, which currently provides baseflow to the River Niger, is the focus of local demand to increase access to water for drinking, livestock watering, and supplementary irrigation.},
	number = {9},
	journal = {Environmental Earth Sciences},
	author = {Abdou Mahaman, Rabilou and Nazoumou, Yahaya and Favreau, Guillaume and Issoufou Ousmane, Boukari and Boucher, Marie and Abdou Babaye, Maman Sani and Lawson, Fabrice M. A. and Vouillamoz, Jean-Michel and Guéro, Abdou and Legchenko, Anatoly and Taylor, Richard Graham},
	month = apr,
	year = {2023},
	pages = {202},
}

@article{issoufou_ousmane_changes_2023,
	title = {Changes in aquifer properties along a seasonal river channel of the {Niger} {Basin}: {Identifying} groundwater recharge pathways in a dryland environment},
	volume = {197},
	issn = {1464-343X},
	url = {https://www.sciencedirect.com/science/article/pii/S1464343X22002941},
	doi = {10.1016/j.jafrearsci.2022.104742},
	abstract = {In drylands of tropical Africa, groundwater plays a fundamental role in alleviating food insecurity and adapting to the effects of climate change. Substantial uncertainty persists in the renewability of groundwater resources in drylands and recharge pathways through the surface geology. Here we characterize the architecture and hydrogeological properties of alluvium and underlying sandstone and crystalline basement rocks along the ephemeral River Goulbi de Maradi in the Iullemmeden Basin of Niger using Magnetic Resonance Soundings (MRS), Time-Domain Electromagnetic (TDEM) soundings, and borehole lithological data. Considerable variations in lithological facies and hydrophysical properties are found along a series of 5 transects perpendicular to the seasonal/ephemeral river channel and adjacent plateaux of the Continental Hamadien (CH) sandstone. The CH aquifer comprises a pebbly sand facies upstream and sandstone clay facies downstream with Farak-type sandstones located at the base of the two facies. Consistent with these variations in facies, the geophysical parameters decrease from 19\%, 390 ms, and 800 Ω m upstream to 3\%, 160 ms, and 10 Ω m downstream, respectively for effective porosity, relaxation time, and resistivity. The transmissivity and specific yield estimated from the decline of MRS longitudinally also vary from upstream to downstream. The combined use of surface geophysics constrained by lithological borehole logs provides vital insight into groundwater replenishment in this dryland environment.},
	journal = {Journal of African Earth Sciences},
	author = {Issoufou Ousmane, Boukari and Nazoumou, Yahaya and Favreau, Guillaume and Abdou Babaye, Maman Sani and Abdou Mahaman, Rabilou and Boucher, Marie and Issoufa, Ibrahim and Lawson, Fabrice M.A. and Vouillamoz, Jean-Michel and Legchenko, Anatoly and Taylor, Richard G.},
	month = jan,
	year = {2023},
	pages = {104742},
}

@article{hiernaux_allometric_2023,
	title = {Allometric equations to estimate the dry mass of {Sahel} woody plants mapped with very-high resolution satellite imagery},
	volume = {529},
	issn = {0378-1127},
	url = {https://www.sciencedirect.com/science/article/pii/S0378112722006478},
	doi = {10.1016/j.foreco.2022.120653},
	abstract = {Very high-resolution satellite images and deep learning are achieving the mapping of individual trees and shrubs over large areas in Africa. Each woody plant is precisely georeferenced and defined by its crown area and, sometimes, its height. The challenge is to build allometric equations for foliage, wood and root dry masses based either on crown area alone, or the product crown area × tree height as independent variables regardless of species. This was met by reanalyzing existing Sahel woody plant data from destructive sampling. Overall, the foliage (seasonal maximum), wood and root dry masses were measured on 900, 698 and 26 trees or shrubs from 27, 26 and 5 species respectively. The regression models tested for foliage, wood or root masses were linear or power functions using a range of different approaches: Ordinary least square (OLS) regression after log–log transform with or without Baskerville correction (1972), and non-linear regressions (NLR). All the models outputs were intercompared for fit indicators and prediction uncertainty, as well as the resulting trends in root to wood ratio, and foliage to wood ratio over the range of crown areas. This process selected a set of OLS log–log equations with crown area as independent variable. When the Baskerville correction is applied the approximation errors are 0.4 kg Dry Matter (DM) for foliage, 12.2 for wood and 6.3 for roots, aggregating at 13.8 kg DM per tree. These allometry equations were compared to published equations for tropical trees, most from the more humid tropics that were generally based on stem diameter, tree height and wood density. This paper’s allometry predictions were within the range of these other allometry equations, reinforcing the confidence in their use even beyond the Sahel domain towards sub-humid savannas.},
	journal = {Forest Ecology and Management},
	author = {Hiernaux, Pierre and Issoufou, Hassane Bil-Assanou and Igel, Christian and Kariryaa, Ankit and Kourouma, Moussa and Chave, Jérôme and Mougin, Eric and Savadogo, Patrice},
	month = feb,
	year = {2023},
	keywords = {Sahel, Africa drylands, Allometry, Foliage, Root, Sudan, Wood},
	pages = {120653},
}

@article{morel_terrestrial_2022,
	title = {Terrestrial or oceanic forcing? {Water} level variations in coastal lagoons constrained by river inflow and ocean tides},
	volume = {169},
	doi = {10.1016/j.advwatres.2022.104309},
	journal = {Advances in Water Resources},
	author = {Morel, Yves and Chaigneau, Alexis and Okpeitcha, Victor and Stieglitz, Thomas and Assogba, Arnaud and Duhaut, Thomas and Rétif, Fabien and Peugeot, Christophe and Sohou, Zacharie},
	month = sep,
	year = {2022},
	pages = {104309},
}

@article{chaigneau_seasonal_2022,
	title = {From seasonal flood pulse to seiche: {Multi}-frequency water-level fluctuations in a large shallow tropical lagoon ({Nokoué} {Lagoon}, {Benin})},
	volume = {267},
	issn = {0272-7714},
	url = {https://www.sciencedirect.com/science/article/pii/S0272771422000270},
	doi = {10.1016/j.ecss.2022.107767},
	abstract = {This study investigated the main water-level (WL) variability modes of Nokoué Lagoon in Benin (West-Africa). The average WL ranges between 1.3 and 2.3 m between the low- and high-water seasons. Seasonal as well as weak interannual variations between 2018 and 2019 are driven by rainfall regime over the catchment and associated river inflow. At sub-monthly scales, the lagoon is tidally choked: ocean tides can reach 90 cm, whereas in the lagoon semi-diurnal and diurnal tides hardly reach few centimeters. Choking conditions vary with river inflow and ocean tide amplitude, correctly represented by a simple tidal choking model. Diurnal modulation and asymmetry of the tide are stronger (weaker) during high (low) water period. We also observed WL variations of ±5–10 cm at a fortnightly frequency, stronger during wet (high-water) season. Superimposed on the seasonal, fortnightly and tidal WL variations, we further observed short-term high-frequency seiche events. Mostly observed during dry (low-water) conditions, they are characterized by typical standing-wave oscillations of 5–10 cm amplitudes and 3 h periods. They are forced by the passage of fast-moving squall-lines that induce strong wind variations, heavy rainfalls and rapid drop-off of the air temperature. Results obtained in this study provide useful metrics for the validation of flood forecasting models to be implemented in Benin, and elsewhere on the West African coastline.},
	journal = {Estuarine, Coastal and Shelf Science},
	author = {Chaigneau, Alexis and Okpeitcha, Olaègbè Victor and Morel, Yves and Stieglitz, Thomas and Assogba, Arnaud and Benoist, Morgane and Allamel, Pierre and Honfo, Jules and Awoulmbang Sakpak, Thierry Derol and Rétif, Fabien and Duhaut, Thomas and Peugeot, Christophe and Sohou, Zacharie},
	month = apr,
	year = {2022},
	keywords = {Lagoons, Nokoué, Seiches, Tides, Water-levels, Wavelet analysis},
	pages = {107767},
}

@article{reiner_more_2023,
	title = {More than one quarter of {Africa}’s tree cover is found outside areas previously classified as forest},
	volume = {14},
	issn = {2041-1723},
	url = {https://doi.org/10.1038/s41467-023-37880-4},
	doi = {10.1038/s41467-023-37880-4},
	abstract = {The consistent monitoring of trees both inside and outside of forests is key to sustainable land management. Current monitoring systems either ignore trees outside forests or are too expensive to be applied consistently across countries on a repeated basis. Here we use the PlanetScope nanosatellite constellation, which delivers global very high-resolution daily imagery, to map both forest and non-forest tree cover for continental Africa using images from a single year. Our prototype map of 2019 (RMSE = 9.57\%, bias = −6.9\%). demonstrates that a precise assessment of all tree-based ecosystems is possible at continental scale, and reveals that 29\% of tree cover is found outside areas previously classified as tree cover in state-of-the-art maps, such as in croplands and grassland. Such accurate mapping of tree cover down to the level of individual trees and consistent among countries has the potential to redefine land use impacts in non-forest landscapes, move beyond the need for forest definitions, and build the basis for natural climate solutions and tree-related studies.},
	number = {1},
	journal = {Nature Communications},
	author = {Reiner, Florian and Brandt, Martin and Tong, Xiaoye and Skole, David and Kariryaa, Ankit and Ciais, Philippe and Davies, Andrew and Hiernaux, Pierre and Chave, Jérôme and Mugabowindekwe, Maurice and Igel, Christian and Oehmcke, Stefan and Gieseke, Fabian and Li, Sizhuo and Liu, Siyu and Saatchi, Sassan and Boucher, Peter and Singh, Jenia and Taugourdeau, Simon and Dendoncker, Morgane and Song, Xiao-Peng and Mertz, Ole and Tucker, Compton J. and Fensholt, Rasmus},
	month = may,
	year = {2023},
	pages = {2258},
}

@article{bodjrenou_hydrological_2023,
	title = {Hydrological modeling with physics-based models in the oueme basin: {Issues} and perspectives for simulation optimization},
	volume = {48},
	doi = {10.1016/j.ejrh.2023.101448},
	author = {Bodjrenou, René and Sintondji, Luc and Comandan, Françoise},
	month = aug,
	year = {2023},
	pages = {101448},
}

@article{baldi_assessing_2023,
	title = {Assessing the {Return} {Periods} and {Hydroclimatic} {Parameters} for {Rainwater} {Drainage} in the {Coastal} {City} of {Cotonou} in {Benin} under {Climate} {Variability}},
	volume = {2023},
	issn = {1687-9309},
	url = {https://doi.org/10.1155/2023/1752805},
	doi = {10.1155/2023/1752805},
	abstract = {Cotonou, the economic capital of Benin, is suffering from the impacts of climate change, particularly evident through recurrent floods. To effectively manage these floods and address this issue, it is crucial to have a deep understanding of return periods and hydroclimatic parameters (such as intensity-duration-frequency (IDF) curves and related coefficients), which are essential for designing stormwater drainage structures. Determining return periods and these parameters requires statistical analysis of extreme events, and this analysis needs to be regularly updated in response to climate change. The objective of this study was to determine the necessary return periods and hydroclimatic parameters to improve stormwater drainage systems in the city and its surroundings areas. This required annual maximum precipitation series of 1, 2, 3, 6, 12, and 24\&\#x2009;h for 20\&\#x2009;years length (1999\&\#x2013;2018) as well as flood record data. The intensity series, derived by dividing the amount of rainfall by its duration, was adjusted using Gumbel\&\#x2019;s law. IDF curves were constructed based on Montana and Talbot models, and their coefficients were determined according to the corresponding return periods. In 2010, which witnessed devastating floods in the country, the return period for the most intense rainfall events was 40\&\#x2009;years, followed by 2013 with a return period of 13.4\&\#x2009;years. Consequently, the commonly used 10-year return period for the design of stormwater drainage structures in Cotonou is insufficient. The Talbot model produced the lowest mean square errors for each quantile series and coefficients of determination closest to one, indicating that the parameters obtained from this model are well suited for designing hydraulic structures in Cotonou. The hydroclimatic parameters presented in this study will contribute to the improved design of hydraulic structures in the city of Cotonou.},
	journal = {Advances in Meteorology},
	author = {Badou, Djigbo Félicien and Hounkanrin, José and Hounkpè, Jean and Sintondji, Luc Ollivier and Emmanuel Lawin, Agnidé},
	editor = {Baldi, Marina},
	month = sep,
	year = {2023},
	note = {Publisher: Hindawi},
	pages = {1752805},
}

@article{chagnaud_reviser_2023,
	title = {Réviser les courbes intensité-durée-fréquence dans un contexte de nouvelle donne hydro-climatique : de la détection de tendances à l’application opérationnelle},
	volume = {109},
	issn = {null},
	url = {https://doi.org/10.1080/27678490.2023.2293085},
	doi = {10.1080/27678490.2023.2293085},
	abstract = {Dans le contexte actuel de transition vers un monde plus chaud, le climat d?aujourd?hui n?est déjà plus celui d?hier. Parmi les multiples conséquences de ce réchauffement global, l?intensification des précipitations pourrait entraîner une augmentation du risque d?inondation, poussant sphères opérationnelles et académiques à travailler conjointement pour adapter les pratiques à des conditions hydro-climatique évolutives. Au centre de cette adaptation se trouve la question de la modélisation statistique des précipitations et du calcul des courbes intensité-durée-fréquence qui en résultent, avec deux enjeux partagés. D?une part, des recherches innovantes sont à mener pour adapter les outils utilisés dans un contexte stationnaire. D?autre part, les utilisateurs de courbes IDF sont en attente d?une démarche leur permettant de poursuivre leur mission dans ce contexte de transition climatique. Nous proposons ici une démarche qui répond à ces enjeux avec deux objectifs : i) établir un diagnostic robuste de l?intensification des pluies extrêmes sur un spectre d?échelles spatiales et temporelles, et ii) permettre aux acteurs en charge du dimensionnement d?infrastructures et de la prévention du risque d?inondation de mettre à jour leurs pratiques. Le Sahel constitue un cas d?étude particulièrement pertinent mais la démarche exposée et les points de discussion qui en découlent se veulent génériques.},
	number = {1},
	journal = {LHB},
	author = {Chagnaud, Guillaume and Panthou, Geremy and Vischel, Théo and Lebel, Thierry},
	month = dec,
	year = {2023},
	note = {Publisher: Taylor \& Francis},
	pages = {2293085},
}

@article{normandin_quantification_2024,
	title = {Quantification of surface water extent and volume in the {Inner} {Niger} {Delta} ({IND}) over 2000–2022 using multispectral imagery and radar altimetry},
	volume = {39},
	issn = {1010-6049},
	url = {https://doi.org/10.1080/10106049.2024.2311203},
	doi = {10.1080/10106049.2024.2311203},
	number = {1},
	journal = {Geocarto International},
	author = {Normandin, Cassandra and Frappart, Frédéric and Bourrel, Luc and Diepkilé, Adama Telly and Mougin, Eric and Zwarts, Leo and Blarel, Fabien and Egon, Flavien and Wigneron, Jean-Pierre},
	month = jan,
	year = {2024},
	note = {Publisher: Taylor \& Francis},
	keywords = {AMMA-CATCH},
	pages = {2311203},
}

@article{merk_significance_2024,
	title = {The significance of the leaf area index for  evapotranspiration estimation in {SWAT}-{T} for  characteristic land cover types of {West} {Africa}},
	volume = {28},
	issn = {1607-7938},
	url = {https://hess.copernicus.org/articles/28/5511/2024/},
	doi = {10.5194/hess-28-5511-2024},
	number = {24},
	journal = {Hydrol. Earth Syst. Sci.},
	author = {Merk, F. and Schaffhauser, T. and Anwar, F. and Tuo, Y. and Cohard, J.-M. and Disse, M.},
	month = dec,
	year = {2024},
	note = {Publisher: Copernicus Publications},
	keywords = {AMMA-CATCH},
	pages = {5511--5539},
}

@article{mamadou_quality_2025,
	title = {Quality control of eddy covariance fluxes of two ecosystem types with local flux-variance similarity functions in {West} {Africa}},
	volume = {314},
	issn = {0169-8095},
	url = {https://www.sciencedirect.com/science/article/pii/S016980952400557X},
	doi = {10.1016/j.atmosres.2024.107775},
	abstract = {Ecosystem capacity studies for carbon sequestration and water extraction are largely conditioned by Eddy Covariance (EC) measurement availability and quality. Our study aims at evaluating several procedures of EC data qualification. Indeed, quality control of EC data is generally ensured by stationarity and well-developed turbulence tests. The latter is based on integral turbulence characteristic (ITC) models. In this study, we revisited the quality control procedure using locally established ITC models for wind speed components and atmospheric scalars (temperature, humidity and carbon dioxide molar densities) in unstable and stable conditions. We also considered the interdependence of flux qualities because of the corrections applied to fluxes during their preprocessing. The analyses were carried out using one year of data collected above a woodland forest and mixed crop sites, both situated in Northern Benin, West Africa. From these analyzes we note that the quality flags vary depending on the use of local or existing ITC models. Also, the test of turbulence development on atmospheric scalars, previously neglected, is of great importance in the quality control of data. Thus, taking into account the ITC models associated with the atmospheric scalars established locally in the well-developed turbulence test as well as taking into account the interdependence of the flux quality have considerably improved the standard quality control procedure used in effectively filtering unrealistic flux data while keeping a considerable percentage of good and medium quality data.},
	journal = {Atmospheric Research},
	author = {Mamadou, Ossénatou and Hounsinou, Miriam and Koukoui, Djidjoho Renaud Roméo and Cohard, Jean-Martial and Afouda, Simon and Biron, Romain and Kempf, Jean and Ouani, Théodore and Kounouhewa, Basile},
	month = mar,
	year = {2025},
	keywords = {West Africa, Quality control, vegetation, AMMA-CATCH, Benin, Eddy covariance data, Integral turbulence characteristics},
	pages = {107775},
}

@article{diedhiou_simple_2024,
	title = {Simple scaling of extreme precipitation regime in {Senegal}},
	volume = {23},
	issn = {2468-2276},
	url = {https://www.sciencedirect.com/science/article/pii/S246822762300488X},
	doi = {10.1016/j.sciaf.2023.e02034},
	abstract = {Extreme precipitation exhibits high temporal and spatial variability, and understanding this variability is crucial for designing hydraulic infrastructures and assessing the impacts of natural risks such as floods and droughts. The Simple Scaling (SS) model, which describes the dependence of extreme rainfall statistics on timescales, is used to estimate Intensity Duration Frequency (IDF) curves. This study aims to evaluate the validity of the Simple Scaling (SS) hypothesis for 14 rain gauges in Senegal and explore the existence of breaks in temporal scaling regimes (transition regimes). For the analysis of extreme characteristics, we considered the Annual Maximum Series (AMS) of precipitation in sub-hourly and supra-daily durations ranging from 10 min to 7 days. The empirical validation of the SS models was confirmed for the majority of the scaling intervals. We identified two scaling breaks, indicating the presence of three scaling regimes: short durations (SD), intermediate durations (ID), and long durations (LD). The spatial variation of scaling exponents reveals the existence of different scaling regimes across Senegal. The results are valuable for modeling the spatial distribution of scaling exponents, which can aid in characterizing IDF curves at ungauged locations.},
	journal = {Scientific African},
	author = {Diedhiou, Cheikh Waly and Panthou, Geremy and Diatta, Samo and Sané, Youssouph and Vischel, Théo and Camara, Moctar},
	month = mar,
	year = {2024},
	keywords = {AMMA-CATCH, Senegal, GEVSS, IDF, Precipitation extremes, Simple scaling},
	pages = {e02034},
}

@article{agbohessou_modelling_2024,
	title = {Modelling {CO2} and {N2O} emissions from soils in silvopastoral systems of the {West} {African} {Sahelian} band},
	volume = {21},
	issn = {1726-4189},
	url = {https://bg.copernicus.org/articles/21/2811/2024/},
	doi = {10.5194/bg-21-2811-2024},
	number = {11},
	journal = {Biogeosciences},
	author = {Agbohessou, Y. and Delon, C. and Grippa, M. and Mougin, E. and Ngom, D. and Gaglo, E. K. and Ndiaye, O. and Salgado, P. and Roupsard, O.},
	month = jun,
	year = {2024},
	note = {Publisher: Copernicus Publications},
	pages = {2811--2837},
}

@article{i_diack_combining_2024,
	title = {Combining {UAV} and {Sentinel}-2 {Imagery} for {Estimating} {Millet} {FCover} in a {Heterogeneous} {Agricultural} {Landscape} of {Senegal}},
	volume = {17},
	issn = {2151-1535},
	doi = {10.1109/JSTARS.2024.3373508},
	journal = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing},
	author = {{I. Diack} and {S. M. Diene} and {L. Louise} and {D. A. Aziz} and {H. Benjamin} and {R. Olivier} and {L. Philippe} and {A. Alain} and {S. Idrissa} and {D. Moussa}},
	year = {2024},
	keywords = {AMMA-CATCH},
	pages = {7305--7322},
}

@article{sow_calibrating_2024,
	title = {Calibrating the {STICS} soil-crop model to explore the impact of agroforestry parklands on millet growth},
	volume = {306},
	issn = {0378-4290},
	url = {https://www.sciencedirect.com/science/article/pii/S0378429023003994},
	doi = {10.1016/j.fcr.2023.109206},
	abstract = {Context
Agroforestry systems provide critical benefits for food security and climate change mitigation. Yet, they are complex and heteregoneous sytems hard to optimize. The use of process-based crop models provides an opportunity to understand better the interactions between soil, crop, tree and climate and explore the impact of agroforestry on crop growth, for contrasting crop management.
Objective
The objectives of this study were to i) calibrate the soil-crop STICS model for pearl millet (Pennisetum glaucum) in order to simulate millet potential growth and impact of water and nitrogen limitations on millet growth in open fields and ii) explore the impacts of the parkland tree Faidherbia albida on millet performance for contrasting N fertilizer inputs.
Methods
We gathered a comprehensive database of 28 agronomically contrasting situations, ranging from near-potential growth to drought- and N-stress, either on-station or in a farmer’s home- or bush-fields. Parameters governing relevant plant and soil processes for grain yield were calibrated in a stepwise procedure. The calibrated model was used to explore the impact on millet growth of the widely reported benefits of Faidherbia albida, namely a minimum reduction in radiation thanks to the peculiar reverse phenology of this tree, improvement of soil water content at the beginning of the growing season and of organic nitrogen in the topsoil.
Results
Model simulations with the calibration dataset were reasonably accurate for aboveground biomass and grain yield. Normalized Root Mean Square Errors (nRMSE) for these variables were 29\% and 26\%, respectively; model efficiency (EF) was 0.58 for both. The nRMSE ranged from 33\% to 53\% for Soil Water Content (SWC), plant N uptake, grain number, and leaf-area index (LAI). Model accuracy was lower with the evaluation dataset. In the virtual experiment, millet yield decreased with incoming solar radiation, but only at levels of shading (e.g. below 80\% of the radiation obtained with full sun) that do not occur under Faidherbia. The decline was greater when millet was fertilized. Increasing the initial soil water content did not affect simulated millet growth. Simulated millet aboveground biomass and grain yield increased with higher organic nitrogen contents of the topsoil, by 80\% when millet was not fertilizer, but only by 25\% when millet was fertilized.
Implications
This study provides the first set of comprehensively calibrated parameters for applying STICS to pearl millet in open cropland. A virtual experiment with historical climate suggests that the benefits of Faidherbia decrease if farmers intensify crop production by adding more mineral N fertilizer. Hence, precise fertilizer management is recommended in Faidherbia parklands. These results illustrate the benefits of process-based crop modelling for better understanding the functioning of agroforestry systems.},
	journal = {Field Crops Research},
	author = {Sow, Sidy and Senghor, Yolande and Sadio, Khardiatou and Vezy, Rémi and Roupsard, Olivier and Affholder, François and N’dienor, Moussa and Clermont-Dauphin, Cathy and Gaglo, Espoir Koudjo and Ba, Seydina and Tounkara, Adama and Balde, Alpha Bocar and Agbohessou, Yelognissè and Seghieri, Josiane and Sall, Saidou Nourou and Couedel, Antoine and Leroux, Louise and Jourdan, Christophe and Diaite, Diaminatou Sanogo and Falconnier, Gatien N.},
	month = feb,
	year = {2024},
	keywords = {Calibration, Validation, AMMA-CATCH, Senegal, Crop model, Sustainable intensification, Virtual experiment},
	pages = {109206},
}

@article{wieckowski_eddy_2024,
	title = {Eddy covariance measurements reveal a decreased carbon sequestration strength 2010–2022 in an {African} semiarid savanna},
	volume = {30},
	issn = {1354-1013},
	url = {https://doi.org/10.1111/gcb.17509},
	doi = {10.1111/gcb.17509},
	abstract = {Abstract Monitoring the changes of ecosystem functioning is pivotal for understanding the global carbon cycle. Despite its size and contribution to the global carbon cycle, Africa is largely understudied in regard to ongoing changes of its ecosystem functioning and their responses to climate change. One of the reasons is the lack of long-term in situ data. Here, we use eddy covariance to quantify the net ecosystem exchange (NEE) and its components?gross primary production (GPP) and ecosystem respiration (Reco) for years 2010?2022 for a Sahelian semiarid savanna to study trends in the fluxes. Significant negative trends were found for NEE (12.7?±?2.8?g C?m2?year?1), GPP (39.6?±?7.9?g C?m2?year?1), and Reco (32.2?±?8.9?g C?m2?year?1). We found that NEE decreased by 60\% over the study period, and this decrease was mainly caused by stronger negative trends in rainy season GPP than in Reco. Additionally, we observed strong increasing trends in vapor pressure deficit, but no trends in rainfall or soil water content. Thus, a proposed explanation for the decrease in carbon sink strength is increasing atmospheric dryness. The warming climate in the Sahel, coupled with increasing evaporative demand, may thus lead to decreased GPP levels across this biome, and lowering its CO2 sequestration.},
	number = {9},
	urldate = {2024-12-23},
	journal = {Global Change Biology},
	author = {Wieckowski, Aleksander and Vestin, Patrik and Ardö, Jonas and Roupsard, Olivier and Ndiaye, Ousmane and Diatta, Ousmane and Ba, Seydina and Agbohessou, Yélognissè and Fensholt, Rasmus and Verbruggen, Wim and Gebremedhn, Haftay Hailu and Tagesson, Torbern},
	month = sep,
	year = {2024},
	note = {Publisher: John Wiley \& Sons, Ltd},
	keywords = {eddy covariance, Sahel, rainfall, AMMA-CATCH, climate change, carbon loss, semiarid savanna, vapor pressure deficit, water availability},
	pages = {e17509},
}

@article{s_mansour_diene_improving_2024,
	title = {Improving {Pearl} {Millet} {Yield} {Estimation} {From} {UAV} {Imagery} in the {Semiarid} {Agroforestry} {System} of {Senegal} {Through} {Textural} {Indices} and {Reflectance} {Normalization}},
	volume = {12},
	issn = {2169-3536},
	doi = {10.1109/ACCESS.2024.3460107},
	journal = {IEEE Access},
	author = {{S. Mansour Diene} and {I. Diack} and {A. Audebert} and {O. Roupsard} and {L. Leroux} and {A. Aziz Diouf} and {M. Mbaye} and {R. Fernandez} and {M. Diallo} and {I. Sarr}},
	year = {2024},
	keywords = {AMMA-CATCH},
	pages = {132626--132643},
}

@article{de_fleury_highly_2024,
	title = {Highly turbid and eutrophic small water bodies in {West} {Africa} well identified by a {CNN} {U}-{Net} algorithm},
	issn = {2352-9385},
	url = {https://www.sciencedirect.com/science/article/pii/S2352938524002763},
	doi = {10.1016/j.rsase.2024.101412},
	abstract = {Although high-resolution multispectral optical imagery is increasingly being used to monitor continental surface waters more easily than ever before, there are still limitations to the methods used to extract water bodies. Detecting water becomes particularly difficult in the presence of aquatic vegetation or trees, or when spectral variations across the water surface are high. These limitations pose significant challenges in West Africa, where such cases are numerous, hindering the application of widely used methods and leading to a reduced quality of various existing datasets. As a result, the region lacks comprehensive information on the number of water bodies, their surface area, their spatial distribution and their typology. In this study, we propose a method based on a convolutional neural network based on a U-net architecture, which we apply to images from the Sentinel-2 multispectral instrument acquired in November 2020 and March 2018, corresponding to the maximum and minimum water area extent during the 2016–2020 period. We observe a much larger number of lakes than in current datasets, a large proportion of which are small and temporary. Overall, 29,265 water bodies were classified in November 2020 and 8,093 in March 2018 over an area of 1,340,450 km2 in the central Sahel, with sizes ranging from 0.002 km2 to 1,162 km2. In addition, a wide diversity of optical water types was found across the water bodies: hypereutrophic water bodies dominate, accounting for 67.9\% in November 2020, followed by very turbid water bodies representing 26.1\%. The Convolutional Neural Network U-Net algorithm successfully identified water bodies with aquatic vegetation or obscured by trees, as well as extremely turbid small lakes and reservoirs, which are often missing in global datasets. Such improved mapping capability has important implications for the monitoring of water resources and water quality, which are pivotal for the livelihoods of the region.},
	journal = {Remote Sensing Applications: Society and Environment},
	author = {de Fleury, Mathilde and Grippa, Manuela and Brandt, Martin and Fensholt, Rasmus and Reiner, Florian and Kovacs, Gyula Maté and Kergoat, Laurent},
	month = dec,
	year = {2024},
	keywords = {West Africa, AMMA-CATCH, CNN, Typology, Water bodies, Water extraction},
	pages = {101412},
}

@article{mamadou_meteorological_2024,
	title = {Meteorological conditions and second-order moments of wind speed components over a nonuniform terrain in {Dangbo}, southeastern {Benin}},
	volume = {136},
	issn = {1436-5065},
	url = {https://doi.org/10.1007/s00703-024-01043-x},
	doi = {10.1007/s00703-024-01043-x},
	abstract = {We analyze in this work the second-order moments and turbulence intensities of wind speed components during convective conditions over a non-uniform terrain in Dangbo, southeast Benin. Turbulence and boundary layer forcing measurements were conducted within the Institute of Mathematics and Physics in the framework of the ASEEW@ (Assessment of Surface Ecosystems Exchanges in West Africa) research project. The measurements obtained during the intensive phase of the project, the 2021-year, revealed a remarkable annual variation in the main meteorological conditions. Despite a high amount of humidity (relative humidity {\textgreater} 60\%) at the site all year long, thermal gradient between the underground and air was large as much and exceeded on average 6 °C. These conditions favor an instability that happens earlier in the day during the wet season compare to the dry season. The sensible heat flux had a bell-shaped curve with a relatively low seasonal difference. The maximum value of Turbulent Kinetic Energy (TKE) was obtained during high wind speed events, friction velocity in correspondence with the highest fluxes of momentum and sensible heat. Results also show that the second order-moments of the three wind speed components follow Monin–Obukhov Similarity Theory in unstable conditions. Finally, all these findings can be useful for dedicated heat and water vapor modelling strategies in the Atmospheric Boundary Layer.},
	number = {6},
	journal = {Meteorology and Atmospheric Physics},
	author = {Mamadou, Ossénatou and Mariscal, Armand and Koukoui, Djidjoho Renaud Roméo and Hounsinou, Miriam and Kounouhéwa, Basile},
	month = oct,
	year = {2024},
	keywords = {AMMA-CATCH},
	pages = {47},
}

@article{ndiaye_potential_2024,
	title = {Potential contribution of land cover change on flood events in the {Senegal} {River} basin},
	volume = {6},
	issn = {2624-9375},
	url = {https://www.frontiersin.org/journals/water/articles/10.3389/frwa.2024.1447577},
	journal = {Frontiers in Water},
	author = {Ndiaye, Assane and Arnault, Joël and Mbaye, Mamadou Lamine and Sy, Souleymane and Camara, Moctar and Lawin, Agnidé Emmanuel and Kunstmann, Harald},
	year = {2024},
	keywords = {AMMA-CATCH},
}

@article{bakker_intercomparison_2024,
	title = {Intercomparison of optical scattering turbidity sensors for a wide range of suspended sediment types and concentrations},
	volume = {245},
	issn = {0341-8162},
	url = {https://www.sciencedirect.com/science/article/pii/S0341816224005046},
	doi = {10.1016/j.catena.2024.108307},
	abstract = {To monitor the effects of rapid changes in climate and land use on sediment export from erodible environments, it is crucial to accurately quantify highly fluctuating suspended sediment concentrations (SSCs) in contrasted river systems that drain small to mesoscale catchments. To this end, we investigate the turbidity-based quantification of SSCs in the range of 0.05–100 g/L through laboratory experiments performed with 7 different types of turbidity sensors and sediments from 10 watersheds. We find that measurements of scattered light from multiple angles may allow for: (1) an extended monitoring range with SSCs up to 10–100 g/L, where enhanced uncertainty may occur near the transition in the effective operational ranges of the underlying signals (typically somewhere in the range of 1–10 g/L); and/or (2) a slightly reduced sensitivity to sediment properties. The specific turbidity of the investigated sensors is inversely related to particle diameter (D10) for SSCs up to 1–5 g/L. Backscatter and combined-signal sensors also show a dependency on sediment colour (CIE a∗), which becomes particularly prominent at SSCs above 10 g/L. We relate this increase in colour dependency with SSC to the expected effect of cumulative near-infrared light absorption associated with multiple scattering. We discuss covarying physical properties of naturally occurring river sediment that can dampen or enhance measurement sensitivity and result in turbidity-based SSC rating curves that may strongly differ in magnitude and form from curves derived for industrially prepared material that is often used for sensor calibration. Although the differences in SSC per sensor among sediment types are generally less than one order of magnitude, the systematic errors and uncertainties associated with high SSCs are typically greater than one order of magnitude and may disproportionally affect the quantification of sediment loads during large-magnitude flow events.},
	journal = {CATENA},
	author = {Bakker, Maarten and Legout, Cédric and Biron, Romain and Nord, Guillaume and Bouteiller, Caroline Le and Boithias, Laurie and Camenen, Benoît and Cotel, Solenn and Coulaud, Catherine and Denis, Hervé and Dramais, Guillaume and Droujko, Jessica and Fovet, Ophélie and Freche, Guilhem and Grippa, Manuela and Coz, Jérôme Le and Lucas, Antoine and Martinez, Jean-Michel and Meric, François and Mora, Henri and Némery, Julien and Payandi-Rolland, Dahédrey and Pierrefeu, Gilles and Probst, Anne and Probst, Jean-Luc and Raclot, Damien and Ribolzi, Olivier and Rousseau, Christophe and Salvador-Blanes, Sébastien and Santini, William and Seve, Fabien and Thollet, Fabien and Vanhooydonck, Pierre and Zanker, Sébastien},
	month = oct,
	year = {2024},
	keywords = {Particle size, Backscattering, Mountainous and Mediterranean environments, Multiple scattering, Nephelometry, Sediment colour, Turbidity ratio},
	pages = {108307},
}

@article{batablinle_climate_2024,
	title = {Climate, water, hydropower, wind speed and wind energy potential resources assessments using weather time series data, downscaled regional circulation models: {A} case study for {Mono} {River} {Basin} in the {Gulf} of {Guinea} region},
	volume = {224},
	issn = {0960-1481},
	url = {https://www.sciencedirect.com/science/article/pii/S0960148124001642},
	doi = {10.1016/j.renene.2024.120099},
	abstract = {Hydropower and wind energy are important renewable energies source in Gulf Guinea region, but they are sensitive to climate change, because the changing climate may alter atmospheric and hydrological conditions. In this study, firstly we analyzed the historical hydro-climate data in connection with changes in Mono river of Gulf Guinea region discharge and their associated impacts on hydropower generation and assessed the future hydropower availability in different climate scenarios. Secondly, statistical methods are used to examine past and future wind speed (WS) and wind energy potential. We used historical data (1981–2010) obtained from the National Meteorology Agency in Togo and Benin and a multi-model ensemble for future projections data (2021–2050) of eight selected Regional Climate Models (RCMs) under Representative Concentration Pathway (RCP) under scenarios 4.5 and 8.5. We found in the recent past years that the temperature and evaporation increase during dry season, while flows and hydropower generation decreased. The multi-model ensemble used have announced that in general, the decreasing trend of the rainfall and increasing trend of temperature is projected to be higher in RCP 8.5 than RCP 4.5, in the near future (2021–2050). Overall, the annual hydropower potential the hydropower will decrease between 8 and 19.3\% under the RCP4.5 and 9 and 29\% under the RCP8.5 while the monthly hydropower potential is projected to decrease by 4–41\% under the RCP4.5 and by 6–47\% under the RCP8.5 in the same period. Concerning the wind speed and the potential wind power, the observed results show that both the Weibull and Rayleigh approximations provided a better fit for the wind speed data. The projected of wind speed and wind power density (2021–2050) at an annual timescale is similar to the monthly timescale of wind speed and wind power density at 90 m height. The multi-model ensemble indicate that projected wind speeds (WS) are between 5 and 10 m/s under the RCP4.5 and, between 3 and 12 m/s under the RCP8.5 while wind power density is projected by 15–250 w/m2, and by 13–357 w/m2 under the RCP4.5 and under the RCP8.5, respectively. South and North of Mono basin, have higher WPD and are promising for installing wind turbines for small-scale power generation.},
	journal = {Renewable Energy},
	author = {Batablinlè, Lamboni and Bazyomo, Serge Dimitri and Badou, Félicien D. and Jean, Hounkpè and Hodabalo, Kamou and Zakari, Djibib and Banna, Magolmeena and Lawin, Agnidé Emmanuel},
	month = apr,
	year = {2024},
	keywords = {Climatic data, Gulf of Guinea region, Hhydropower, Models, Mono basin, Wind power},
	pages = {120099},
}

@article{etchanchu_multiscale_2025,
	title = {Multiscale analysis of existing actual evapotranspiration products over agropastoral {Sahel}},
	volume = {651},
	issn = {0022-1694},
	url = {https://www.sciencedirect.com/science/article/pii/S0022169424019814},
	doi = {10.1016/j.jhydrol.2024.132585},
	abstract = {Understanding the spatiotemporal variability of actual evapotranspiration (ET) is a critical issue for better water resources management from plot to basin scale. It is particularly true in the Sahelian region which is very vulnerable in terms of water and agricultural resources, but also very scarcely monitored. This study aims to improve understanding of ET in Sahelian agrosystems by comparing twenty ET products and collections on two areas in Central Senegal and South-Western Niger: Breathing Earth System Simulation (BESS), Derive Optimal Linear Combination Evapotranspiration (DOLCE) v2.1 and v3.0, ERA5 and ERA5-Land, FLUXCOM-RS, Global Land Data Assimilation System (GLDAS) on Noah and Catchment Land Surface Model (CLSM), Global Land Evaporation: the Amsterdam Methodology (GLEAM) v3.5a, v3.5b, v3.6a and v3.6b, Modern-Era Retrospective analysis for Research and Applications v2 (MERRA-2), MODIS Global Evapotranspiration products (MOD16/MYD16), Penman-Monteith Leuning version 2 (PML\_V2) v0.1 and v0.1.7, Reliability Ensemble Averaging (REA), Simplified Surface Energy Balance for operational applications (SSEBop) and Water Productivity through Open access of Remotely sensed derived data (WaPOR). In order to assess the abilities and drawbacks of each product, a multi-scale analysis is first performed at local scale with different temporal aggregation levels (daily, decadal, monthly). The best performing products, like GLEAM, MERRA-2 or GLDAS-Noah, have low spatial resolution (≥0.25°), but shows really good agreement with ET measurements (RMSE ∼ 0.5 mm.d-1, R2 ≥ 0.8). A multi-scale spatial analysis with different spatial aggregation levels (1, 10 and 25 km) is then performed on interannual composite maps of annual and seasonal ET. Results highlight the different spatiotemporal behaviour of all the products. Products such as ERA5-Land and PML\_V2 0.1.7 stand out in this comparison as their higher resolution allows them to describe the spatial patterns of ET realistically and more precisely while having relatively good performances at local scale (RMSE ∼ 0.6 mm.d-1, R2 ≥ 0.7). Overall, the comparison highlights the need to consider soil moisture to accurately estimate ET in the Sahelian region, as the products considering it generally show better performances. It also points out the lack of a high quality and resolution ET product over the Sahel. Future satellite missions, as well as data fusion techniques, could help to fill up this gap and propose a reference product on Sahelian ecosystems.},
	journal = {Journal of Hydrology},
	author = {Etchanchu, Jordi and Demarty, Jérôme and Dezetter, Alain and Farhani, Nesrine and Thiam, Pape Biteye and Allies, Aubin and Bodian, Ansoumana and Boulet, Gilles and Chahinian, Nanée and Diop, Lamine and Mainassara, Ibrahim and Ndiaye, Pape Malick and Ollivier, Chloé and Olioso, Albert and Roupsard, Olivier},
	month = apr,
	year = {2025},
	keywords = {West Africa, Remote sensing, Evapotranspiration, AMMA-CATCH, Intercomparison, Land surface models},
	pages = {132585},
}

@article{clermont-dauphin_faidherbia_2023,
	title = {Faidherbia albida trees form a natural buffer against millet water stress in agroforestry parklands in a {Sub}-sahelian environment},
	volume = {27 (3)},
	url = {https://popups.uliege.be/1780-4507/index.php?id=20477},
	doi = {10.25518/1780-4507.20477},
	abstract = {Description of the subject. In central-west Senegal, agroforestry parklands dominated by Faidherbia albida trees might
protect the millet crop against drought and increase agricultural production. Only few studies examined the water relations
between the trees and the crop in farmers’ field conditions.
Objectives. Our aim was to explore the effect of F. albida trees on millet water potential and the implications for millet yield
in F. albida parklands.
Method. Sixty-eight F. albida plots scattered in five villages were selected in the 2019 rainy season. In each plot, a pair of
millet subplots, “close-to-tree subplot” and “open subplot”, was monitored. We measured millet predawn and midday leaf
water potential (Ψp, Ψm), top soil bulk density, water content and temperature, and grain and straw yields at harvest.
Results. Pairwise comparisons of Ψp and Ψm of millet indicated better and more stable water status and lower soil temperature
and bulk density in close-to-tree subplots. Soil water was sometimes lower in close-to-tree subplots, perhaps because the
higher crop biomass in this location resulted in higher water loss through crop transpiration. Tree effects on millet grain and
straw yield were positive or null. Correlations between millet yield and Ψp, Ψm measured around flowering were weak.
Conclusions. Given their common positive effects on millet water status and yield, F. albida trees could play a key role
in promoting sustainable agriculture under the changing climate conditions. Millet yield increase due to the tree proximity
was likely due to changes induced by the tree on multiple environmental resources. The interactions of micro-pedoclimatic
conditions, livestock and tree management (e.g. density, pruning intensity) on the tree effects should be the focus of future
studies.
Leaf water potential, interactions, yield, biodiversity, West Africa},
	number = {3},
	journal = {Biotechnologie, Agronomie, Société et Environnement (BASE) ; special issue “Agroforestry in West Africa”. Accepted September 2023},
	author = {Clermont-Dauphin, C and Ndienor, M and Leroux, L and Ba, H S and Bongers, F and Jourdan, C and Roupsard, O and Do, F and Cournac, C and Seghieri, J},
	year = {2023},
	keywords = {agrobiodiversity, farmers’ practices, Leaf water potential, tree/crop interactions, West Africa., yield},
	pages = {1--14},
}

@article{diongue_probabilistic_2023,
	title = {A probabilistic framework for assessing the hydrological impact of {Faidherbia} albida in an arid area of {Senegal}},
	volume = {622},
	url = {https://www.sciencedirect.com/science/article/pii/S0022169423006595},
	doi = {10.1016/j.jhydrol.2023.129717},
	abstract = {The Faidherbia tree (Faidherbia albida) is frequently used as an intercrop in Sahelian agroforestry parklands due to its multi-purpose advantages and reverse phenology. However, its effect upon the water balance remains unclear, due to the challenges in directly measuring water fluxes in the underlying vadose zone. Mechanistic hydrological models can be inversely calibrated on transient observations and used to partition different hydrological components, but the computational burden of the analysis can become impractical if the model itself is computationally expensive. To overcome this limitation, and to provide novel insights into the hydrological role of Faidherbia, we combine a low-fidelity, one-dimensional hydrological model (HYDRUS-1D) with a kriging-based correction function to emulate the response of a high-fidelity, two-dimensional axisymmetric description of the system (HYDRUS-2D). Multiannual measurements of soil moisture and sap flow in a Senegal agroforestry parkland are used in conjunction with Bayesian inference to calibrate the resulting validated multifidelity surrogate, and to inversely estimate soil hydraulic and root water uptake parameters. Results show that the model can reproduce observations with good accuracy and limited uncertainty for both the calibration and the validation phases, and also confirm the phreatophytic behaviour of Faidherbia by indicating the existence of a moderately compensated root water uptake. Moreover, a local sensitivity analysis suggests that a fully compensated uptake could potentially reduce groundwater recharge by 13\%. Interestingly, estimated soil hydraulic parameters hint at the possibility of root-induced changes in soil hydraulic properties that mimic preferential and/or macropore flow, resulting in sustained recharge fluxes (≈ 26\% of the annual precipitation). The analysis indicates that overall, Faidherbia could have a net positive effect upon the water balance in arid areas.},
	journal = {Journal of Hydrology},
	author = {Diongue, Djim M L and Brunetti, Giuseppe and Stumpp, Christine and Do, Frederic C and Roupsard, Olivier and Orange, Didier and Faye, Waly and Sow, Sidy and Jourdan, Christophe and Faye, Serigne},
	year = {2023},
	keywords = {Calibration, Phreatophyte, Arid areas, HYDRUS, Surrogate},
	pages = {129717--129717},
}

@article{diongue_estimating_2023,
	title = {Estimating water fluxes in the critical zone using water stable isotope approaches in the {Groundnut} and {Ferlo} basins of {Senegal}},
	volume = {37},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/hyp.14787},
	doi = {10.1002/hyp.14787},
	abstract = {Abstract Sustainable water management in semi-arid agriculture practices requires quantitative knowledge of water fluxes within the soil-vegetation-atmosphere system. Therefore, we used stable-isotope approaches to evaluate evaporation (Ea), transpiration (Ta), and groundwater recharge (R) at sites in Senegal's Groundnut basin and Ferlo Valley pasture region during the pre-monsoon, monsoon, and post-monsoon seasons of 2021. The approaches were based upon (i) the isothermal evaporation model (for quantifying Ea); (ii) water and isotope mass balances (to partition Ea and Ta for groundnut and pasture); and (iii) the piston displacement method (for estimating R). Ea losses derived from the isothermal evaporation model corresponded primarily to Stage II evaporation, and ranged from 0.02 to 0.09 mm d−1 in the Groundnut basin, versus 0.02–0.11 mm d−1 in Ferlo. At the groundnut site, Ea rates ranged from 0.01 to 0.69 mm d−1; Ta was in the range 0.55–2.29 mm d−1; and the Ta/ETa ratio was 74\%–90\%. At the pasture site, the ranges were 0.02–0.39 mm d−1 for Ea; 0.9–1.69 mm d−1 for Ta; and 62–90\% for Ta/ETa. The ETa value derived for the groundnut site via the isotope approach was similar to those from eddy covariance measurements, and also to the results from the previous validated HYDRUS-1D model. However, the HYDRUS-1D model gave a lower Ta/ETa ratio (23.2\%). The computed groundwater recharge for the groundnut site amounted to less than 2\% of the local annual precipitation. Recommendations are made regarding protocols for preventing changes to isotopic compositions of water in samples that are collected in remote arid regions, but must be analysed days later. The article ends with suggestions for studies to follow up on evidence that local aquifers are being recharged via preferential pathways.},
	number = {1},
	journal = {Hydrological Processes},
	author = {Diongue, Djim M L and Stumpp, Christine and Roupsard, Olivier and Orange, Didier and Do, Frederic C and Faye, Serigne},
	year = {2023},
	pages = {e14787--e14787},
}

@article{siegwart_contribution_2023,
	title = {Contribution of tree and crop roots to soil carbon stocks in a {Sub}-{Sahelian} agroforestry parkland in {Senegal}},
	volume = {352},
	url = {https://www.sciencedirect.com/science/article/pii/S0167880923001834},
	doi = {10.1016/j.agee.2023.108524},
	abstract = {In the Sub-Sahelian region (Senegal), Faidherbia albida trees have been maintained for years in agroforestry parklands for their numerous services offered to people and to crops. The aerial crop biomass and yield are notably greater under the tree crown, but most of this biomass is exported and does not contribute to soil carbon (C) inputs. Belowground litter inputs are crucial, but little is known about the root system distribution, productivity and contribution to soil C inputs. This study aims to assess the field heterogeneity of F. albida and crop root systems along the soil profile based on the distance to the tree to evaluate the root contribution to soil C stocks. During two successive rotations of pearl millet in 2020 and groundnut in 2021, soils and roots were sampled from two locations (Under and Far from the tree), in 5 soil layers to a depth of 150 cm and with three tree replicates. The aerial biomass was also sampled. The annual relative contribution of roots to soil C stocks was estimated as the ratio between root litter-derived C inputs (considering hypothetical root turnover only for trees and the whole root biomass for crops) and soil C stocks. We found a similar crop root biomass density Under and Far from the tree, but the higher root:shoot ratio Far from than Under the tree confirmed the beneficial effect of trees on the aerial crop biomass. Unexpectedly, the tree root biomass density was higher at + 30 m from the trunk than Under the tree in the 30–100 cm soil layer, suggesting a long-distance soil exploration by the trees. Down to 150 cm of depth, the tree root litter contribution to soil C stocks represented 6.1 \% and 7.1 \% of the total root litter-derived C inputs (Under and Far from the tree, respectively). In this type of Sub-Sahelian parklands with low soil C stocks, increasing the tree density or selecting deep and highly rooted crop varieties should be favoured.},
	journal = {Agriculture, Ecosystems \& Environment},
	author = {Siegwart, Lorène and Bertrand, Isabelle and Roupsard, Olivier and Jourdan, Christophe},
	year = {2023},
	keywords = {Pearl millet, Groundnut, Root litter-derived C, Soil C stocks, Soil depth},
	pages = {108524--108524},
}

@article{gning_root_2023,
	title = {Root distribution of {Adansonia} digitata, {Faidherbia} albida and {Borassus} akeassii along a climate gradient in {Senegal}},
	url = {https://link.springer.com/article/10.1007/s10457-023-00813-7},
	journal = {Agroforestry Systems},
	author = {Gning, Fatou and Jourdan, Christophe and Marone, Diatta and Ngom, Daouda and Ræbild, Anders},
	year = {2023},
	pages = {1--11},
}

@article{sarr_estimation_2023,
	title = {Estimation of seasonal water use of {Faidherbia} albida ({Del}.) {A}. {Chev}. in a {Sahelian} agroforestry parkland},
	volume = {27},
	url = {https://popups.uliege.be/1780-4507/index.php?id=20512},
	abstract = {Utilisation saisonnière de l’eau par l’arbre Faidherbia albida (Delile) A.Chev. dans un parc agroforestier du Sahel
Description du sujet. Faidherbia albida est reconnue comme une espèce agroforestière prometteuse. Dans les systèmes agroforestiers, la dynamique de l'utilisation de l'eau par arbre (TWU) est une composante essentielle de son impact sur le rendement des cultures associées et sur le bilan hydrique. On sait peu de choses sur l'absorption d'eau du F. albida, alors qu'une estimation du bilan hydrique à l'échelle écosystémique est cruciale dans le contexte du changement climatique.
Objectifs. L’objectif de cette étude est d’évaluer l’utilisation de l’eau du F. albida pendant une année et déterminer l’implication de la taille de l’arbre, de la saison et de la phénologie.
Méthode. Cinq arbres matures ont été sélectionnés dans un parc agroforestier dans le bassin arachidier à côté du village de Niakhar, au Sénégal, pour y effectuer les mesures de flux de sève. Le flux total par arbre (Q) ou TWU a été calculé et l’enregistrement des paramètres climatiques, de la teneur en eau du sol et des différentes phases phénologiques effectué.
Résultats. Les résultats ont révélé une variabilité significative de TWU entre la saison des pluies et la saison sèche et les stades de feuillaisons. Les valeurs maximales d'utilisation de l'eau ont été observées dans la première partie de la saison sèche, entre décembre et janvier, lorsque les arbres sont en pleine feuillaison, avec une grande variabilité entre les arbres, allant de 118 à 261 l·arbre-1·jour-1. La variation de TWU était faible pendant la saison sèche, puis a atteint des valeurs minimales pendant la phase sans feuilles qui a lieu pendant la saison des pluies.
Conclusions. La consommation d'eau moyenne annuelle a été estimée à environ 40 000 l·arbre-1·an-1, soit 27 mm·arbre-1·an-1, ce qui représente 5,3 \% des précipitations annuelles de 2019 (513 mm). La relation significative entre la consommation d'eau et les phases de feuillaison (R2 = 0,81) suscite la possibilité d'un modèle simple qui permettrait d'estimer l'utilisation de l'eau par les arbres.},
	number = {3},
	journal = {Biotechnologie, Agronomie, Société et Environnement (BASE)},
	author = {Sarr, M S and Diouf, K and Roupsard, O and Rocheteau, A and Orange F., D and Jourdan J., C and Diedhiou, I and Seghieri, J and Do, F},
	year = {2023},
	pages = {196--204},
}

@article{guzinski_improving_2023,
	title = {Improving field-scale crop actual evapotranspiration monitoring with {Sentinel}-3, {Sentinel}-2, and {Landsat} data fusion},
	volume = {125},
	url = {https://www.sciencedirect.com/science/article/pii/S1569843223004119},
	doi = {10.1016/j.jag.2023.103587},
	abstract = {One of the primary applications of satellite Land Surface Temperature (LST) observations lies in their utilization for modeling of actual evapotranspiration (ET) in agricultural crops, with the primary goals of monitoring and enhancing irrigation practices and improving crop water use productivity, as stipulated by Sustainable Development Goal (SDG) indicator 6.4.1. Evapotranspiration is a complex and dynamic process, both temporally and spatially, necessitating LST observations with high spatio-temporal resolution. Presently, none of the existing spaceborne thermal sensors can provide quasi-daily field-scale LST observations, prompting the development of methods for data fusion (thermal sharpening) of observations from various shortwave and thermal sensors to meet this spatio-temporal requirement. Previous research has demonstrated the effectiveness of combining shortwave-multispectral Sentinel-2 observations with thermal-infrared Sentinel-3 observations to derive daily, field-scale LST and ET estimates. However, these studies also highlighted limitations in capturing the distinct thermal contrast between cooler LST in irrigated agricultural areas and the hotter, adjacent dry regions. In this study, we aim to address this limitation by incorporating information on thermal spatial variability observed by Landsat satellites into the data fusion process, without being constrained by infrequent or cloudy Landsat thermal observations and while retaining the longwave radiance emission captured by the Sentinel-3 thermal sensor at its native resolution. Two approaches are evaluated, both individually and as a complementary combination, and validated against in situ LST measurements. The best performing approach, which leads to reduction in root mean square error of up to 1.5 K when compared to previous research, is subsequently used to estimate parcel-level actual evapotranspiration. The ET modeling process has also undergone various improvements regarding the gap-filling of input and output data, input datasets and code implementation. The resulting ET is validated using lysimeters and eddy covariance towers in Spain, Lebanon, Tunisia, and Senegal resulting in minimal overall bias (systematic underestimation of less than 0.07 mm/day) and a low root mean square error (down to 0.84 mm/day) when using fully global input datasets. The enhanced LST sharpening methodology is sensor agnostic and should remain relevant for the upcoming thermal missions while the accuracy of the modeled ET fluxes is encouraging for further utilization of observations from Sentinel satellites, and other Copernicus data, for monitoring SDG indicator 6.4.1.},
	journal = {International Journal of Applied Earth Observation and Geoinformation},
	author = {Guzinski, Radoslaw and Nieto, Héctor and Ramo Sánchez, Rubén and Sánchez, Juan Manuel and Jomaa, Ihab and Zitouna-Chebbi, Rim and Roupsard, Olivier and López-Urrea, Ramón},
	year = {2023},
	keywords = {Surface energy balance, Remote sensing, Land surface temperature, Irrigated agriculture},
	pages = {103587--103587},
}

@article{diongue_evaluation_2022,
	title = {Evaluation of parameterisation approaches for estimating soil hydraulic parameters with {HYDRUS}-{1D} in the groundnut basin of {Senegal}},
	volume = {67},
	url = {https://doi.org/10.1080/02626667.2022.2142474},
	doi = {10.1080/02626667.2022.2142474},
	abstract = {ABSTRACTSoil hydraulic parameters (SHPs) required as inputs for numerical models are scarce in Sahelian regions. Instead, they are estimated using pedotransfer functions (PTFs), but their ability to simulate soil water dynamics has not been evaluated. This study aims to parameterize SHPs with seven different PTFs and inverse modelling to examine their ability to simulate water fluxes in Senegal?s Groundnut basin. We used four years of field measurements of soil water content (SWC) and actual evapotranspiration (ETa) under pearl millet and groundnut crop rotation for model evaluation. Inverse modelling for SWC (root mean square error [RMSE] ≤ 0.015 cm3 cm?3) and ETa (RMSE ≤ 0.62 mm d?1) yielded the best model performance compared to PTFs (0.024?0.175 cm3 cm?3 and 0.68?0.96 mm d?1, respectively). Where field measurements are lacking for inverse estimation, three of the seven tested PTFs yielded good modelling results and could be used as a parsimonious approach for cultivated Sahelian soils.},
	number = {15},
	journal = {Hydrological Sciences Journal},
	author = {Diongue, Djim M L and Roupsard, Olivier and Do, Frederic C and Stumpp, Christine and Orange, Didier and Sow, Sidy and Jourdan, Christophe and Faye, Serigne},
	year = {2022},
	pages = {2327--2343},
}

@article{leroux_spatialized_2022,
	title = {A spatialized assessment of ecosystem service relationships in a multifunctional agroforestry landscape of {Senegal}},
	volume = {853},
	url = {https://www.sciencedirect.com/science/article/pii/S0048969722058065},
	doi = {10.1016/j.scitotenv.2022.158707},
	abstract = {Agroforestry systems are an integral part of Sub-Saharan agricultural landscapes. Studies conducted at tree or plot scales on the supply of ecosystem services (ES) suggest that agroforestry practices are a promising way to build multifunctional agricultural landscapes. However, the current characterization and understanding of how multiple ES are associated across such heterogeneous agricultural landscapes are still limited. This study provides the first characterization of the multiple ESs supplied by a Sahelian Faidherbia albida agroforestry parkland and their relationships. Relying on field data for 11 ES indicators, recent advances in remote sensing-derived information, and blending different ES mapping approaches, we first assessed the spatial heterogeneity of the supply of each ES. We found that the majority of ES indicators remained below ES potential values over the study area by 25 \% to 50 \%, revealing that there is a considerable scope for increasing the ES supply in the F. albida parkland. Then, using a scoring approach, we analyzed the supply of multiple ESs. We observed a large number of hotspots and a clear effect of the proximity of F. albida trees fostering the supply of multiple ESs in their vicinity. Finally, we mapped and analyzed the dominant relationships – trade-offs, synergies or losses – between ESs from a cooccurrence spatial approach. We showed that significant trade-offs and losses (58 \% of the area) between ESs can exist in the F. albida parkland. Interestingly, we also showed that synergies occurred mainly up to 10 m from the F. albida trees, suggesting that synergies need to be increased beyond this threshold. By adopting an original ES valuation framework, we provided basic insights into ESs and their relationships. The different maps and information generated can support public debates and target new policies fostering the multifunctionality of F. albida parklands as well as in various other parklands of West Africa.},
	journal = {Science of The Total Environment},
	author = {Leroux, L and Clermont-Dauphin, C and Ndienor, M and Jourdan, C and Roupsard, O and Seghieri, J},
	year = {2022},
	keywords = {Remote sensing, Ecosystem services mapping, parkland, Spatial co-occurrence, Synergies, Trade-offs},
	pages = {158707--158707},
}

@article{siegwart_root_2022,
	title = {Root litter decomposition in a sub-{Sahelian} agroforestry parkland dominated by {Faidherbia} albida},
	volume = {198},
	url = {https://www.sciencedirect.com/science/article/pii/S0140196321002627},
	doi = {10.1016/j.jaridenv.2021.104696},
	abstract = {In agroforestry systems, fine roots grow at several depths due to the mixture of trees and annual crops. The decomposition of fine roots contributes to soil organic carbon stocks and may impact soil fertility, particularly in poor soils, such as those encountered in sub-Sahelian regions. The aim of our study was to measure the decomposition rate of root litter from annual and perennial species according to soil depth and location under and far from trees in a sub-Sahelian agroforestry parkland. Soil characteristics under and far from the trees were analysed from topsoil to 200 cm depth. Faidherbia tree, pearl millet and cowpea root litter samples were buried in litterbags for 15 months at 20, 40, 90 and 180 cm depths. Root litter decomposition was mainly impacted by soil moisture and soil depth. Faidherbia decomposed more slowly (36 ± 12\% remaining mass after 15 months) than cowpea and pearl millet roots (23 ± 7\% and 29 ± 11\% respectively). Pearl millet aboveground biomass, at harvesting time, was twice as high under (9918 g m-2) than far (4332 g m-2) from the tree, and belowground biomass (0–200 cm of depth) was 89 g m-2 and 64 g m-2 under and far from the tree, respectively. Faidherbia fine roots contributed slightly (p-value {\textless} 0.1) to higher stocks of C under the tree (7761 ± 346 g m-2) than far from it (5425 ± 558 g m-2) and from 0 cm down to 200 cm depth.},
	journal = {Journal of Arid Environments},
	author = {Siegwart, Lorène and Bertrand, Isabelle and Roupsard, Olivier and Duthoit, Maxime and Jourdan, Christophe},
	year = {2022},
	keywords = {Soil depth, Root litter quality, Soil nutrients, Soil organic carbon},
	pages = {104696--104696},
}

@article{lembrechts_global_2022,
	title = {Global maps of soil temperature},
	volume = {28},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.16060},
	doi = {10.1111/gcb.16060},
	abstract = {Abstract Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km2 resolution for 0–5 and 5–15 cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1-km2 pixels (summarized from 8519 unique temperature sensors) across all the world's major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (−0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications.},
	number = {9},
	journal = {Global Change Biology},
	author = {Lembrechts, Jonas J and van den Hoogen, Johan and Aalto, Juha and Ashcroft, Michael B and De Frenne, Pieter and Kemppinen, Julia and Kopecký, Martin and Luoto, Miska and Maclean, Ilya M D and Crowther, Thomas W and Bailey, Joseph J and Haesen, Stef and Klinges, David H and Niittynen, Pekka and Scheffers, Brett R and Van Meerbeek, Koenraad and Aartsma, Peter and Abdalaze, Otar and Abedi, Mehdi and Aerts, Rien and Ahmadian, Negar and Ahrends, Antje and Alatalo, Juha M and Alexander, Jake M and Allonsius, Camille Nina and Altman, Jan and Ammann, Christof and Andres, Christian and Andrews, Christopher and Ardö, Jonas and Arriga, Nicola and Arzac, Alberto and Aschero, Valeria and Assis, Rafael L and Assmann, Jakob Johann and Bader, Maaike Y and Bahalkeh, Khadijeh and Barančok, Peter and Barrio, Isabel C and Barros, Agustina and Barthel, Matti and Basham, Edmund W and Bauters, Marijn and Bazzichetto, Manuele and Marchesini, Luca Belelli and Bell, Michael C and Benavides, Juan C and Benito Alonso, José Luis and Berauer, Bernd J and Bjerke, Jarle W and Björk, Robert G and Björkman, Mats P and Björnsdóttir, Katrin and Blonder, Benjamin and Boeckx, Pascal and Boike, Julia and Bokhorst, Stef and Brum, Bárbara N S and Brůna, Josef and Buchmann, Nina and Buysse, Pauline and Camargo, José Luís and Campoe, Otávio C and Candan, Onur and Canessa, Rafaella and Cannone, Nicoletta and Carbognani, Michele and Carnicer, Jofre and Casanova-Katny, Angélica and Cesarz, Simone and Chojnicki, Bogdan and Choler, Philippe and Chown, Steven L and Cifuentes, Edgar F and Čiliak, Marek and Contador, Tamara and Convey, Peter and Cooper, Elisabeth J and Cremonese, Edoardo and Curasi, Salvatore R and Curtis, Robin and Cutini, Maurizio and Dahlberg, C Johan and Daskalova, Gergana N and de Pablo, Miguel Angel and Della Chiesa, Stefano and Dengler, Jürgen and Deronde, Bart and Descombes, Patrice and Di Cecco, Valter and Di Musciano, Michele and Dick, Jan and Dimarco, Romina D and Dolezal, Jiri and Dorrepaal, Ellen and Dušek, Jiří and Eisenhauer, Nico and Eklundh, Lars and Erickson, Todd E and Erschbamer, Brigitta and Eugster, Werner and Ewers, Robert M and Exton, Dan A and Fanin, Nicolas and Fazlioglu, Fatih and Feigenwinter, Iris and Fenu, Giuseppe and Ferlian, Olga and Fernández Calzado, M Rosa and Fernández-Pascual, Eduardo and Finckh, Manfred and Higgens, Rebecca Finger and Forte, T'ai G W and Freeman, Erika C and Frei, Esther R and Fuentes-Lillo, Eduardo and García, Rafael A and García, María B and Géron, Charly and Gharun, Mana and Ghosn, Dany and Gigauri, Khatuna and Gobin, Anne and Goded, Ignacio and Goeckede, Mathias and Gottschall, Felix and Goulding, Keith and Govaert, Sanne and Graae, Bente Jessen and Greenwood, Sarah and Greiser, Caroline and Grelle, Achim and Guénard, Benoit and Guglielmin, Mauro and Guillemot, Joannès and Haase, Peter and Haider, Sylvia and Halbritter, Aud H and Hamid, Maroof and Hammerle, Albin and Hampe, Arndt and Haugum, Siri V and Hederová, Lucia and Heinesch, Bernard and Helfter, Carole and Hepenstrick, Daniel and Herberich, Maximiliane and Herbst, Mathias and Hermanutz, Luise and Hik, David S and Hoffrén, Raúl and Homeier, Jürgen and Hörtnagl, Lukas and Høye, Toke T and Hrbacek, Filip and Hylander, Kristoffer and Iwata, Hiroki and Jackowicz-Korczynski, Marcin Antoni and Jactel, Hervé and Järveoja, Järvi and Jastrzębowski, Szymon and Jentsch, Anke and Jiménez, Juan J and Jónsdóttir, Ingibjörg S and Jucker, Tommaso and Jump, Alistair S and Juszczak, Radoslaw and Kanka, Róbert and Kašpar, Vít and Kazakis, George and Kelly, Julia and Khuroo, Anzar A and Klemedtsson, Leif and Klisz, Marcin and Kljun, Natascha and Knohl, Alexander and Kobler, Johannes and Kollár, Jozef and Kotowska, Martyna M and Kovács, Bence and Kreyling, Juergen and Lamprecht, Andrea and Lang, Simone I and Larson, Christian and Larson, Keith and Laska, Kamil and le Maire, Guerric and Leihy, Rachel I and Lens, Luc and Liljebladh, Bengt and Lohila, Annalea and Lorite, Juan and Loubet, Benjamin and Lynn, Joshua and Macek, Martin and Mackenzie, Roy and Magliulo, Enzo and Maier, Regine and Malfasi, Francesco and Máliš, František and Man, Matěj and Manca, Giovanni and Manco, Antonio and Manise, Tanguy and Manolaki, Paraskevi and Marciniak, Felipe and Matula, Radim and Mazzolari, Ana Clara and Medinets, Sergiy and Medinets, Volodymyr and Meeussen, Camille and Merinero, Sonia and Mesquita, Rita de Cássia Guimarães and Meusburger, Katrin and Meysman, Filip J R and Michaletz, Sean T and Milbau, Ann and Moiseev, Dmitry and Moiseev, Pavel and Mondoni, Andrea and Monfries, Ruth and Montagnani, Leonardo and Moriana-Armendariz, Mikel and Morra di Cella, Umberto and Mörsdorf, Martin and Mosedale, Jonathan R and Muffler, Lena and Muñoz-Rojas, Miriam and Myers, Jonathan A and Myers-Smith, Isla H and Nagy, Laszlo and Nardino, Marianna and Naujokaitis-Lewis, Ilona and Newling, Emily and Nicklas, Lena and Niedrist, Georg and Niessner, Armin and Nilsson, Mats B and Normand, Signe and Nosetto, Marcelo D and Nouvellon, Yann and Nuñez, Martin A and Ogaya, Romà and Ogée, Jérôme and Okello, Joseph and Olejnik, Janusz and Olesen, Jørgen Eivind and Opedal, Øystein H and Orsenigo, Simone and Palaj, Andrej and Pampuch, Timo and Panov, Alexey V and Pärtel, Meelis and Pastor, Ada and Pauchard, Aníbal and Pauli, Harald and Pavelka, Marian and Pearse, William D and Peichl, Matthias and Pellissier, Loïc and Penczykowski, Rachel M and Penuelas, Josep and Petit Bon, Matteo and Petraglia, Alessandro and Phartyal, Shyam S and Phoenix, Gareth K and Pio, Casimiro and Pitacco, Andrea and Pitteloud, Camille and Plichta, Roman and Porro, Francesco and Portillo-Estrada, Miguel and Poulenard, Jérôme and Poyatos, Rafael and Prokushkin, Anatoly S and Puchalka, Radoslaw and Pușcaș, Mihai and Radujković, Dajana and Randall, Krystal and Ratier Backes, Amanda and Remmele, Sabine and Remmers, Wolfram and Renault, David and Risch, Anita C and Rixen, Christian and Robinson, Sharon A and Robroek, Bjorn J M and Rocha, Adrian V and Rossi, Christian and Rossi, Graziano and Roupsard, Olivier and Rubtsov, Alexey V and Saccone, Patrick and Sagot, Clotilde and Sallo Bravo, Jhonatan and Santos, Cinthya C and Sarneel, Judith M and Scharnweber, Tobias and Schmeddes, Jonas and Schmidt, Marius and Scholten, Thomas and Schuchardt, Max and Schwartz, Naomi and Scott, Tony and Seeber, Julia and Segalin de Andrade, Ana Cristina and Seipel, Tim and Semenchuk, Philipp and Senior, Rebecca A and Serra-Diaz, Josep M and Sewerniak, Piotr and Shekhar, Ankit and Sidenko, Nikita V and Siebicke, Lukas and Siegwart Collier, Laura and Simpson, Elizabeth and Siqueira, David P and Sitková, Zuzana and Six, Johan and Smiljanic, Marko and Smith, Stuart W and Smith-Tripp, Sarah and Somers, Ben and Sørensen, Mia Vedel and Souza, José João L L and Souza, Bartolomeu Israel and Souza Dias, Arildo and Spasojevic, Marko J and Speed, James D M and Spicher, Fabien and Stanisci, Angela and Steinbauer, Klaus and Steinbrecher, Rainer and Steinwandter, Michael and Stemkovski, Michael and Stephan, Jörg G and Stiegler, Christian and Stoll, Stefan and Svátek, Martin and Svoboda, Miroslav and Tagesson, Torbern and Tanentzap, Andrew J and Tanneberger, Franziska and Theurillat, Jean-Paul and Thomas, Haydn J D and Thomas, Andrew D and Tielbörger, Katja and Tomaselli, Marcello and Treier, Urs Albert and Trouillier, Mario and Turtureanu, Pavel Dan and Tutton, Rosamond and Tyystjärvi, Vilna A and Ueyama, Masahito and Ujházy, Karol and Ujházyová, Mariana and Uogintas, Domas and Urban, Anastasiya V and Urban, Josef and Urbaniak, Marek and Ursu, Tudor-Mihai and Vaccari, Francesco Primo and Van de Vondel, Stijn and van den Brink, Liesbeth and Van Geel, Maarten and Vandvik, Vigdis and Vangansbeke, Pieter and Varlagin, Andrej and Veen, G F and Veenendaal, Elmar and Venn, Susanna E and Verbeeck, Hans and Verbrugggen, Erik and Verheijen, Frank G A and Villar, Luis and Vitale, Luca and Vittoz, Pascal and Vives-Ingla, Maria and von Oppen, Jonathan and Walz, Josefine and Wang, Runxi and Wang, Yifeng and Way, Robert G and Wedegärtner, Ronja E M and Weigel, Robert and Wild, Jan and Wilkinson, Matthew and Wilmking, Martin and Wingate, Lisa and Winkler, Manuela and Wipf, Sonja and Wohlfahrt, Georg and Xenakis, Georgios and Yang, Yan and Yu, Zicheng and Yu, Kailiang and Zellweger, Florian and Zhang, Jian and Zhang, Zhaochen and Zhao, Peng and Ziemblińska, Klaudia and Zimmermann, Reiner and Zong, Shengwei and Zyryanov, Viacheslav I and Nijs, Ivan and Lenoir, Jonathan},
	year = {2022},
	pages = {3110--3144},
}

@article{faye_climatic_2020,
	title = {Climatic variability in the {Sine}-{Saloum} basin and its impacts on water resources: case of the {Sob} and {Diohine} watersheds in the region of {Niakhar}},
	volume = {383},
	journal = {Proceedings of the International Association of Hydrological Sciences},
	author = {Faye, Waly and Fall, Awa Niang and Orange, Didier and Do, Frédéric and Roupsard, Olivier and Kane, Alioune},
	year = {2020},
	pages = {391--399},
}

@article{gbodjo_object-based_2020,
	title = {Object-{Based} {Multi}-{Temporal} and {Multi}-{Source} {Land} {Cover} {Mapping} {Leveraging} {Hierarchical} {Class} {Relationships}},
	volume = {12},
	url = {://WOS:000571051200001},
	doi = {10.3390/rs12172814},
	abstract = {European satellite missions Sentinel-1 (S1) and Sentinel-2 (S2) provide at high spatial resolution and high revisit time, respectively, radar and optical images that support a wide range of Earth surface monitoring tasks, such as Land Use/Land Cover mapping. A long-standing challenge in the remote sensing community is about how to efficiently exploit multiple sources of information and leverage their complementarity, in order to obtain the most out of radar and optical data. In this work, we propose to deal with land cover mapping in an object-based image analysis (OBIA) setting via a deep learning framework designed to leverage the multi-source complementarity provided by radar and optical satellite image time series (SITS). The proposed architecture is based on an extension of Recurrent Neural Network (RNN) enriched via a modified attention mechanism capable to fit the specificity of SITS data. Our framework also integrates a pretraining strategy that allows to exploit specific domain knowledge, shaped as hierarchy over the set of land cover classes, to guide the model training. Thorough experimental evaluations, involving several competitive approaches were conducted on two study sites, namely the Reunion island and a part of the Senegalese groundnut basin. Classification results, 79\% of global accuracy on the Reunion island and 90\% on the Senegalese site, respectively, have demonstrated the suitability of the proposal.},
	number = {17},
	journal = {Remote Sensing},
	author = {Gbodjo, Y J E and Ienco, D and Leroux, L and Interdonato, R and Gaetano, R and Ndao, B},
	year = {2020},
}

@article{lembrechts_soiltemp_2020,
	title = {{SoilTemp}: {A} global database of near-surface temperature},
	volume = {26},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.15123},
	doi = {10.1111/gcb.15123},
	abstract = {Abstract Current analyses and predictions of spatially explicit patterns and processes in ecology most often rely on climate data interpolated from standardized weather stations. This interpolated climate data represents long-term average thermal conditions at coarse spatial resolutions only. Hence, many climate-forcing factors that operate at fine spatiotemporal resolutions are overlooked. This is particularly important in relation to effects of observation height (e.g. vegetation, snow and soil characteristics) and in habitats varying in their exposure to radiation, moisture and wind (e.g. topography, radiative forcing or cold-air pooling). Since organisms living close to the ground relate more strongly to these microclimatic conditions than to free-air temperatures, microclimatic ground and near-surface data are needed to provide realistic forecasts of the fate of such organisms under anthropogenic climate change, as well as of the functioning of the ecosystems they live in. To fill this critical gap, we highlight a call for temperature time series submissions to SoilTemp, a geospatial database initiative compiling soil and near-surface temperature data from all over the world. Currently, this database contains time series from 7,538 temperature sensors from 51 countries across all key biomes. The database will pave the way toward an improved global understanding of microclimate and bridge the gap between the available climate data and the climate at fine spatiotemporal resolutions relevant to most organisms and ecosystem processes.},
	number = {11},
	journal = {Global Change Biology},
	author = {Lembrechts, Jonas J and Aalto, Juha and Ashcroft, Michael B and De Frenne, Pieter and Kopecký, Martin and Lenoir, Jonathan and Luoto, Miska and Maclean, Ilya M D and Roupsard, Olivier and Fuentes-Lillo, Eduardo and García, Rafael A and Pellissier, Loïc and Pitteloud, Camille and Alatalo, Juha M and Smith, Stuart W and Björk, Robert G and Muffler, Lena and Ratier Backes, Amanda and Cesarz, Simone and Gottschall, Felix and Okello, Joseph and Urban, Josef and Plichta, Roman and Svátek, Martin and Phartyal, Shyam S and Wipf, Sonja and Eisenhauer, Nico and Pușcaș, Mihai and Turtureanu, Pavel D and Varlagin, Andrej and Dimarco, Romina D and Jump, Alistair S and Randall, Krystal and Dorrepaal, Ellen and Larson, Keith and Walz, Josefine and Vitale, Luca and Svoboda, Miroslav and Finger Higgens, Rebecca and Halbritter, Aud H and Curasi, Salvatore R and Klupar, Ian and Koontz, Austin and Pearse, William D and Simpson, Elizabeth and Stemkovski, Michael and Jessen Graae, Bente and Vedel Sørensen, Mia and Høye, Toke T and Fernández Calzado, M Rosa and Lorite, Juan and Carbognani, Michele and Tomaselli, Marcello and Forte, T'ai G W and Petraglia, Alessandro and Haesen, Stef and Somers, Ben and Van Meerbeek, Koenraad and Björkman, Mats P and Hylander, Kristoffer and Merinero, Sonia and Gharun, Mana and Buchmann, Nina and Dolezal, Jiri and Matula, Radim and Thomas, Andrew D and Bailey, Joseph J and Ghosn, Dany and Kazakis, George and de Pablo, Miguel A and Kemppinen, Julia and Niittynen, Pekka and Rew, Lisa and Seipel, Tim and Larson, Christian and Speed, James D M and Ardö, Jonas and Cannone, Nicoletta and Guglielmin, Mauro and Malfasi, Francesco and Bader, Maaike Y and Canessa, Rafaella and Stanisci, Angela and Kreyling, Juergen and Schmeddes, Jonas and Teuber, Laurenz and Aschero, Valeria and Čiliak, Marek and Máliš, František and De Smedt, Pallieter and Govaert, Sanne and Meeussen, Camille and Vangansbeke, Pieter and Gigauri, Khatuna and Lamprecht, Andrea and Pauli, Harald and Steinbauer, Klaus and Winkler, Manuela and Ueyama, Masahito and Nuñez, Martin A and Ursu, Tudor-Mihai and Haider, Sylvia and Wedegärtner, Ronja E M and Smiljanic, Marko and Trouillier, Mario and Wilmking, Martin and Altman, Jan and Brůna, Josef and Hederová, Lucia and Macek, Martin and Man, Matěj and Wild, Jan and Vittoz, Pascal and Pärtel, Meelis and Barančok, Peter and Kanka, Róbert and Kollár, Jozef and Palaj, Andrej and Barros, Agustina and Mazzolari, Ana C and Bauters, Marijn and Boeckx, Pascal and Benito Alonso, José-Luis and Zong, Shengwei and Di Cecco, Valter and Sitková, Zuzana and Tielbörger, Katja and van den Brink, Liesbeth and Weigel, Robert and Homeier, Jürgen and Dahlberg, C Johan and Medinets, Sergiy and Medinets, Volodymyr and De Boeck, Hans J and Portillo-Estrada, Miguel and Verryckt, Lore T and Milbau, Ann and Daskalova, Gergana N and Thomas, Haydn J D and Myers-Smith, Isla H and Blonder, Benjamin and Stephan, Jörg G and Descombes, Patrice and Zellweger, Florian and Frei, Esther R and Heinesch, Bernard and Andrews, Christopher and Dick, Jan and Siebicke, Lukas and Rocha, Adrian and Senior, Rebecca A and Rixen, Christian and Jimenez, Juan J and Boike, Julia and Pauchard, Aníbal and Scholten, Thomas and Scheffers, Brett and Klinges, David and Basham, Edmund W and Zhang, Jian and Zhang, Zhaochen and Géron, Charly and Fazlioglu, Fatih and Candan, Onur and Sallo Bravo, Jhonatan and Hrbacek, Filip and Laska, Kamil and Cremonese, Edoardo and Haase, Peter and Moyano, Fernando E and Rossi, Christian and Nijs, Ivan},
	year = {2020},
	pages = {6616--6629},
}

@article{roupsard_how_2020,
	title = {How far does the tree affect the crop in agroforestry? {New} spatial analysis methods in a {Faidherbia} parkland},
	volume = {296},
	doi = {10.1016/J.AGEE.2020.106928},
	abstract = {The trees in agroforestry plots create spatial heterogeneity of high interest for adaptation, mitigation, and the provision of ecosystem services. But to what distance, exactly, from the tree? We tested a novel approach, based upon geostatistics and Unmanned Aerial Vehicle (UAV) sensing, to infer the distance at which a single agroforestry tree affects the surrounding under-crop, to map yield, litter (i.e. stover) and compute crop-partial Land Equivalent Ratio (LERcp) at the whole-plot level. In an agro-silvo-pastoral parkland of semi-arid western Africa dominated by the multi-purpose tree Faidherbia albida, we harvested the pearl-millet under-crop at the whole-plot scale (ca. 1 ha) and also in subplot transects, at three distances from the trunks. We observed that the yield was three times higher below the tree crown (135.6 g m−2) than at a distance of five tree-crown radii from the trunk (47.7 g m−2). Through geostatistical analysis of multi-spectral, centimetric-resolution images obtained from an UAV overflight of the entire plot, we determined that the ‘Range’ parameter of the semi-variogram (assumed to be the distance of influence of the trees on the Normalized difference vegetation index (NDVI)) was 17 m. We correlated the yield (r2 = 0.41; RRMSE = 48 \%) and litter production (r2 = 0.46; RRMSE = 35 \%) in subplots with NDVI, and generated yield and litter maps at the whole-plot scale. The measured whole-plot yield (0.73 t ha-1) differed from the one estimated via the UAV mapping by only 20 \%, thereby validating the overall approach. The litter was estimated similarly at 1.05 tC ha-1 yr-1 and mapped. Using a geostatistical proxy for the sole crop, LERcp was estimated 1.16, despite the low tree density. This new method to handle heterogeneity in agroforestry systems is a first application. We also propose strategies for extension to the landscape level.},
	journal = {Agriculture, Ecosystems \& Environment},
	author = {Roupsard, Olivier and Audebert, Alain and Ndour, Adama P. and Clermont-Dauphin, Cathy and Agbohessou, Yelognissè and Sanou, Josias and Koala, Jonas and Faye, Emile and Sambakhe, Diaretou and Jourdan, Christophe and le Maire, Guerric and Tall, Laure and Sanogo, Diaminatou and Seghieri, Josiane and Cournac, Laurent and Leroux, Louise},
	month = jul,
	year = {2020},
	note = {Publisher: Elsevier},
	keywords = {Geostatistics, Distance of influence, Land Equivalent Ratio (LER), Spectral indices, Unmanned Aerial Vehicle (UAV)},
	pages = {106928--106928},
}

@article{diawara_monitoring_2022,
	title = {Monitoring herbaceous vegetation in {Sahel} rangelands over the dry season at {Hombori}, {Mali}: {A} digital photograph approach},
	volume = {60},
	issn = {0141-6707},
	url = {https://doi.org/10.1111/aje.13031},
	doi = {10.1111/aje.13031},
	number = {4},
	urldate = {2025-01-09},
	journal = {African Journal of Ecology},
	author = {Diawara, Mamadou Oumar and Mougin, Eric and Ba, Alassane and Hiernaux, Pierre and Sissoko, Sory and Diakité, Hawa Salif and Soumaguel, Nogmana and Dembélé, Pacôme and Coulibaly, Fanta},
	month = dec,
	year = {2022},
	note = {Publisher: John Wiley \& Sons, Ltd},
	pages = {1368--1373},
}

@article{ha_gnss-r_2023,
	title = {{GNSS}-{R} monitoring of soil moisture dynamics in areas of severe drought: example of {Dahra} in the {Sahelian} climatic zone ({Senegal})},
	volume = {56},
	issn = {null},
	url = {https://doi.org/10.1080/22797254.2022.2156931},
	doi = {10.1080/22797254.2022.2156931},
	number = {1},
	journal = {European Journal of Remote Sensing},
	author = {Ha, Minh-Cuong and Darrozes, José and Llubes, Muriel and Grippa, Manuela and Ramillien, Guillaume and Frappart, Frédéric and Baup, Frédéric and Tagesson, Håkan Torbern and Mougin, Eric and Guiro, Idrissa and Kergoat, Laurent and Nguyen, Huu Duy and Seoane, Lucia and Dufrechou, Gregory and Vu, Phuong-Lan},
	month = dec,
	year = {2023},
	note = {Publisher: Taylor \& Francis},
	pages = {2156931},
}

@article{delon_nitrogen_2022,
	title = {Nitrogen budget and critical load determination at a {Sahelian} grazed grassland site},
	volume = {124},
	issn = {1573-0867},
	url = {https://doi.org/10.1007/s10705-022-10220-6},
	doi = {10.1007/s10705-022-10220-6},
	abstract = {Based on rare and original in situ measurements together with published data, we estimate a complete nitrogen (N) budget for a semi-arid Sahelian grazed grassland located in Dahra (Senegal) in 2014 and 2017. Nitrogen inputs include biological fixation, dry and wet atmospheric deposition, and input from livestock manure. Nitrogen outputs include nitric oxide (NO) and nitrous oxide (N2O) emissions from soils, NO and ammonia (NH3) emissions from biomass burning, NH3 volatilization from manure, ingestion from livestock grazing, uptake by trees and soil leaching. Nitrogen inputs ranged between 11.7 ± 0.5 and 34.4 ± 0.5 kg N ha−1 yr−1 for low and high estimates respectively, and N outputs ranged between 16.4 ± 1.5 and 45.7 ± 1.5 kg N ha−1 yr−1 for low and high estimates respectively, on average for both years. Nitrogen depletion was estimated between 4.7 ± 2.0 and 11.3 ± 2.0 kg N ha−1 yr−1, which involves N mining from soils. The budget is dominated by the impact of livestock through grazing (63\% of the outputs), NH3 volatilization (15\% of the outputs), manure (68\% of the inputs) and atmospheric deposition (19\% of the inputs). The N critical load (Steady State Mass Balance method) ranged from 16.7 ± 0.8 to 47.5 ± 1.7 kg N ha−1 yr−1, showing that the grazed grassland of Dahra was not yet threatened by an excess of N. The assessment of the critical load in Sahelian landscapes depends heavily on livestock participation to the ecosystem equilibrium.},
	number = {1},
	journal = {Nutrient Cycling in Agroecosystems},
	author = {Delon, Claire and Galy-Lacaux, Corinne and Barret, Blandine and Ndiaye, Ousmane and Serça, Dominique and Guérin, Frédéric and Gardrat, Eric and Mougin, Eric and Agbohessou, Yélognissè F. and Probst, Anne},
	month = sep,
	year = {2022},
	pages = {17--34},
}

@inproceedings{mamadou_turbulent_2024,
	address = {Cham},
	title = {Turbulent {Kinetic} {Energy} and {Turbulence} {Dispersion} {Characteristics} {Over} a {Mixed} {Crop} {Area} in {Benin}},
	isbn = {978-3-031-53525-3},
	abstract = {In this study, we analyze turbulent kinetic energy and turbulent dispersion characteristics of four 15-day periods selected in the year 2008. Data were acquired using the eddy covariance method above a mixed crop area located in the northern Benin. The Monin Obukhov Similarity (MOS) theory was used to examine the relationship between the turbulent dispersion characteristics and stability parameters for the four periods investigated. It has been found that the turbulent kinetic energy, friction velocity and turbulent dispersion characteristics showed distinctive variations during the selected periods. During unstable atmospheric conditions, the normalized ratios of lateral, horizontal and vertical wind speeds are larger with respect to those obtained in stable stratification of the atmosphere. The results demonstrate also that the normalized standard deviations of wind speed components follow MOS theory under unstable atmospheric conditions.},
	booktitle = {Advances in {Air} {Quality} {Research} in {Africa}},
	publisher = {Springer Nature Switzerland},
	author = {Mamadou, Ossénatou and Hounsinou, Miriam and Kounouhéwa, Basile},
	editor = {Fomba, Khanneh Wadinga and Tchanche Fankam, Bertrand and Mellouki, Abdelwahid and Westervelt, Daniel M. and Giordano, Michael R.},
	year = {2024},
	keywords = {AMMA-CATCH},
	pages = {89--92},
}

@article{fitts_using_2025,
	title = {Using {PlanetScope} {NDVI} time series to detect the phenology of individual trees in the {Sahel}},
	volume = {321},
	issn = {0034-4257},
	url = {https://www.sciencedirect.com/science/article/pii/S0034425725000549},
	doi = {10.1016/j.rse.2025.114650},
	abstract = {New advancements in satellite technology enable more accurate observation of woody population dynamics, providing greater insights into the underlying processes that influence their change. In this study, we evaluate the use of PlanetScope NDVI time series to track the phenology of individual trees in the Sahel, where ground-based environmental surveys are scarce. Five-year NDVI time series were produced for 398 trees with known species recorded in Mali, Senegal, and Niger. Clouds and high aerosol contamination were filtered using MODIS products and focused on the dry season to minimize the influence of background NDVI directly (through crown influence) or indirectly (through adjacency effects). Each NDVI time series profile was fitted with a spline model to obtain the minimum NDVI day of year during the dry season. PlanetScope NDVI time series accurately captured the photosynthetic phenology of individual tree crowns in the Sahel, with discernable differences between individuals and species. When species were grouped based on four phenology types, deciduous and inverse deciduous species exhibited a relatively consistent phenological pattern across all sites. The phenology of semi-evergreen species and evergreen species, which include species with few leaves, was more heterogeneous. Intra-species variation was relatively modest between sites, and most species maintained a similar NDVI profile, with shifts in leaf phenology events correlating with the timing of the wet season in each site. Overlap between the different phenology groups indicates that transitions between phenology types and species are not clear-cut, and even individuals of the same species can demonstrate plasticity. Furthermore, NDVI profiles were extracted for 500 randomly selected tree samples within eight 10 km2 clip boxes distributed along the West African rainfall gradient from 9.9° to 16.6° latitude at −1.6° longitude. This analysis showed a strong relationship between the phenology of woody plants and the timing and distribution of rainfall at each latitude. Green-up of woody vegetation before herbaceous vegetation was marked in the more southern Sahelo-Sudanian latitudes. Additionally, despite the prolonged dry season in the more northern semi-arid latitudes, trees retained their greenness remarkably late into the dry season. Increased air temperature and dryness as a result of climate change could impact tree function in this region and needs individual-based monitoring.},
	journal = {Remote Sensing of Environment},
	author = {Fitts, Yasmin and Tucker, Compton and Hiernaux, Pierre and Auda, Yves and Kergoat, Laurent},
	month = may,
	year = {2025},
	keywords = {Sahel, AMMA-CATCH, Trees, Phenology, PlanetScope},
	pages = {114650},
}

@article{daouda_boukary_contribution_2023,
	title = {Contribution of assisted natural regeneration ({ANR}) to climate change mitigation and diversification of ecosystem services in {Dan} saga village ({Maradi}-{Niger})},
	volume = {18},
	issn = {25819615},
	url = {https://wjarr.com/content/contribution-assisted-natural-regeneration-anr-climate-change-mitigation-and-diversification},
	doi = {10.30574/wjarr.2023.18.1.0688},
	abstract = {As an agro-ecological intensification technique, assisted natural regeneration (ANR) protects agrosystems and guarantees cereal production in a Sahelian context of high demographic pressure and climate variability. This study aims to assess the local perception of assisted natural regeneration in mitigating the effects of drought and climate change and its impacts on soil fertility and crop production. Surveys, based on a participatory approach of individual and collective consultations, were conducted with stakeholders. The water profile and bulk density of areas under ANR and outside ANR were determined from soil samples taken in the rainy and dry seasons at different depths (0 - 200 cm). Vegetative growth and yield components were monitored on 100 plots of 100 m2 (10x10m) with 50 plots in ANR and 50 in non-ANR areas. The results showed that both zones had the same species composition for the dominant woody species, but their average densities were higher in the areas under assisted natural regeneration than in the areas without. Density is lower in the aureoles close to the village than those far from it in any zone. Soil moisture content is higher in the ANR and non-ANR areas than in the non-ANR area in the shallow horizons. However, in the deep horizons down to 200 cm, the volume moisture is higher in the Non-NAR and Uncovered NAR zones respectively than in the Under-Cover NAR zone. Apart from the seedling density, all agronomic performance parameters are significantly higher in the RNA zone than in the non-RAN zone. In terms of farmers' perception, the practice of ANR attenuates the impacts on natural resources (water, land, vegetation) and on production systems. More than 92.2\% of the respondents reported that increased dust winds, increased night time temperature, decreased rainfall events as well as their amounts in height are the impacts experienced before the practice of ANR. The practice of ANR contributes to the mitigation of climate variability, improvement of soil structure and carbon sequestration.},
	number = {1},
	urldate = {2025-08-24},
	journal = {World Journal of Advanced Research and Reviews},
	author = {{Daouda Boukary} and {Hassimiou Halidou Djabri} and {Karimou Harouna Boureima} and {Hassane Bil-Assanou Issoufou} and {Alzouma Mayaki Zoubeirou}},
	month = apr,
	year = {2023},
	pages = {1186--1196},
	file = {Texte intégral:C\:\\Users\\cohardj\\Zotero\\storage\\LAG6NBK6\\Daouda Boukary et al. - 2023 - Contribution of assisted natural regeneration (ANR) to climate change mitigation and diversification.pdf:application/pdf},
}

@article{noauthor_notitle_nodate,
}

@article{chavezespinoza_sensitivity_2025,
	title = {Sensitivity of {Stable} {Isotope} {Dynamics} to {Parametric} and {Conceptual} {Choices} in {Critical} {Zone} {Hydrological} {Modelling}—{A} {Case} {Study} in {Tropical} {Africa}},
	volume = {39},
	issn = {0885-6087, 1099-1085},
	url = {https://onlinelibrary.wiley.com/doi/10.1002/hyp.70337},
	doi = {10.1002/hyp.70337},
	abstract = {ABSTRACT
            
              Tracer‐enabled hydrological models are increasingly used to investigate water pathways by integrating hydrometric and stable isotope data. While quantifying the sensitivity of model outputs to global parameters is a common practice, structural sensitivity to empirical evaporative fractionation models is rarely explored, despite its critical influence on isotopic signatures, especially in evapotranspiration‐dominated basins. In this study, we build upon the process‐based distributed model EcH
              2
              O‐iso to quantify both types of isotopic sensitivities—conceptual, from changing the Craig and Gordon formulation used to quantify soil evaporative fractionation, widely applied in tracer‐enabled hydrology, and parametric, from varying classical non‐isotopic hydrodynamics parameters—in a tropical savanna basin in northern Benin with mixed land cover (fallow and forest). Looking at five locations and hydrological compartments, covering both local and basin scales, our results show that both types of sensitivities are of similar magnitude and significance, leading to changes in
              δ
              18
              O outputs by several per mil. We further show that the choice of conceptual fractionation framework influences parametric sensitivities, especially locally, while at basin scales, sensitivities decrease as mixing may dominate over fractionation processes. Additionally, we highlight how vegetation‐dependent root uptake further modulates the impact of modelling choices on tracer sensitivity. The differentiated relationships between inputs (parametric and conceptual) and outputs (isotopic time series) not only demonstrate the leverage of isotopic information to identify model configurations but also benchmark how evaporation fractionation formulations may alter the propagation of this information for estimating parameters controlling water storage and fluxes.},
	language = {en},
	number = {11},
	urldate = {2026-01-17},
	journal = {Hydrological Processes},
	author = {Chávez‐Espinoza, Diego and Kuppel, Sylvain and Peugeot, Christophe and Yoshimura, Kei and Vallet‐Coulomb, Christine},
	month = nov,
	year = {2025},
	pages = {e70337},
}

@article{ibrahim_flood_2025,
	title = {Flood risk assessment in a {West} {African} city: case study of {Gounti} {Yena} \textit{kori} in {Niamey}},
	volume = {70},
	issn = {0262-6667, 2150-3435},
	shorttitle = {Flood risk assessment in a {West} {African} city},
	url = {https://www.tandfonline.com/doi/full/10.1080/02626667.2025.2498666},
	doi = {10.1080/02626667.2025.2498666},
	language = {en},
	number = {10},
	urldate = {2026-01-17},
	journal = {Hydrological Sciences Journal},
	author = {Ibrahim, Boubacar and Bouzed, Bouzed Himed and Kumar, Navneet and Nazoumou, Yahaya and Verleysdonk, Sarah and Tischbein, Bernhard and Adamou, Rabani},
	month = jul,
	year = {2025},
	pages = {1602--1618},
}

@article{abdou_mahaman_hydrogeological_2025,
	title = {Hydrogeological dynamics of a large alluvial aquifer in the dryland {Iullemmeden} {Basin} of {Niger}},
	volume = {70},
	issn = {0262-6667, 2150-3435},
	url = {https://www.tandfonline.com/doi/full/10.1080/02626667.2025.2542476},
	doi = {10.1080/02626667.2025.2542476},
	language = {en},
	number = {14},
	urldate = {2026-01-17},
	journal = {Hydrological Sciences Journal},
	author = {Abdou Mahaman, Rabilou and Nazoumou, Yahaya and Favreau, Guillaume and Issoufou Ousmane, Boukari and Boucher, Marie and Abdou Babaye, Maman Sani and Sorensen, James P. R. and Macdonald, Alan M. and Taylor, Richard G.},
	month = oct,
	year = {2025},
	pages = {2465--2478},
}

@article{mant_monitoring_2025,
	title = {Monitoring bacterial contamination of {West} {African} surface waters using {Earth} observation data and machine learning methods},
	volume = {22},
	issn = {26667657},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S2666765725000699},
	doi = {10.1016/j.envadv.2025.100678},
	language = {en},
	urldate = {2026-01-17},
	journal = {Environmental Advances},
	author = {Mant, Marc-Antoine and Robert, Elodie and Nikiema, Hedwige and Boubacar-Moussa, Moussa and Abdourhamane-Toure, Amadou and Funatsu, Beatriz M. and Grippa, Manuela and Kergoat, Laurent and Perez-Saez, Javier and Pradalier, Hugo and Rochelle-Newall, Emma and Robin, Marc},
	month = dec,
	year = {2025},
	keywords = {ressources},
	pages = {100678},
}

@article{alexandre_what_2025,
	title = {What {Does} the {Triple} {Isotopic} {Composition} of {Oxygen} in {Precipitation}, {Groundwater}, {Soil} {Water}, {Plant} {Water}, and {Phytoliths} {Reveal} {About} {Current} and {Past} {Hydrological} {Cycles}?},
	volume = {130},
	issn = {2169-8953, 2169-8961},
	url = {https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024JG008615},
	doi = {10.1029/2024JG008615},
	abstract = {Abstract
            
              Quantitative data are needed to constrain the feedback loops between vegetation and hydroclimate. In this study, the amplitudes of variations in the triple oxygen isotope composition of water at the soil‐plant‐atmosphere interface are measured in savanna and dry forest contexts in West Africa (Benin and Senegal). Comparison of in situ data and model estimates reveals the following: (a) The value of
              17
              O‐excess for reconstructing climate archives is confirmed, given its small variability in precipitation (a few per meg) compared to the very large magnitude of change in the
              17
              O‐excess of phytoliths (hundreds of per meg) in response to RH changes. (b) At the beginning of the dry season, the
              17
              O‐excess in soil water is lower than that of precipitation by only 30 per meg in the sandy‐loam soils and 50 per meg in the sandy soil. This shows the limited contribution of evaporated water to bulk soil water and provides clues to constrain the complex hydrological functioning of soils; (c) The regression line connecting the triple oxygen isotope composition of water in the stems and leaves of grasses and trees can be used to determine the origin of the water absorbed by the roots. Semi‐evergreen trees draw their water from the water table during the dry season, whereas grasses and semi‐evergreen trees use surface water during the wet season. These original data open up new perspectives for the use of the triple oxygen isotope composition of water and phytoliths to better understand current and past hydrological cycles.
            
          , 
            Plain Language Summary
            
              In this study, we examine the triple oxygen isotope composition of water at the soil‐plant‐atmosphere interface and of plant silica (phytoliths), at three instrumented sites in West Africa (Senegal and Benin). By using in situ measurements and a simple mechanistic model, we show that the
              17
              O‐excess, which is a new isotopic marker, varies little in annual precipitation, slightly more in soil water, and significantly in plant water and phytoliths, in link with changes in atmospheric relative humidity. This demonstrates the relevance of using the
              17
              O‐excess of phytoliths for climate reconstructions. Our results additionally show that evaporation affects only a small portion of the water in the soil, even at the very beginning of the rainy season when atmospheric humidity is still low. Finally, we present how the triple isotopic composition of plant water (from grasses and trees) can provide information about the origin of water pumped by the roots: groundwater or surface water. The triple isotopic composition of oxygen is a powerful tool for understanding current and past water cycles.
            
          , 
            Key Points
            
              
                
                  
                    Variability of
                    17
                    O‐excess in precipitation is small compared to that of phytoliths in response to RH change
                  
                
                
                  The triple oxygen isotope composition of water is a powerful tracer of evaporation and mixing in soil and plant waters
                
                
                  The triple oxygen isotope composition of plant water can be used to trace the origin of water taken up by the plants},
	language = {en},
	number = {10},
	urldate = {2026-01-17},
	journal = {Journal of Geophysical Research: Biogeosciences},
	author = {Alexandre, Anne and Outrequin, Clement and Vallet‐Coulomb, Christine and Peugeot, Christophe and Grippa, Manuela and Aleman, Julie and Voigt, Claudia and Landais, Amaelle and Mougin, Eric and Ndiaye, Ousmane and Sonzogni, Corinne and Yang, David Au and Mazur, Jean‐Charles and Couapel, Martine and Ogée, Jérôme and Ouani, Theodore and Afouda, Simon and Wubda, Maxime and Soumaguel, Nogmana and Houngnon, Alfred and Tagesson, Torbern and Fensholt, Rasmus},
	month = oct,
	year = {2025},
	pages = {e2024JG008615},
}

@article{harouna_infiltrability_2025,
	title = {Infiltrability {Variations} on {Surface} {Features} of {Sahelian} {Soils} around {Niamey} ({Southwestern} {Niger})},
	volume = {13},
	issn = {2327-4336, 2327-4344},
	url = {https://www.scirp.org/journal/doi.aspx?doi=10.4236/gep.2025.138017},
	doi = {10.4236/gep.2025.138017},
	number = {08},
	urldate = {2026-01-17},
	journal = {Journal of Geoscience and Environment Protection},
	author = {Harouna, Harouna Amadou and Toure, Amadou Abdourhamane and Moussa, Moussa Boubacar and Grippa, Manuela and Adamou, Salifou Noma and Hassane, Bouba and Ide, Issoufou},
	year = {2025},
	pages = {321--352},
}

@article{girard_performance_2025,
	title = {Performance of the {Surface} {Water} and {Ocean} {Topography} ({SWOT}) {Mission} for {Monitoring} {Small} {Lakes} in {West} {Africa}},
	volume = {18},
	copyright = {https://creativecommons.org/licenses/by/4.0/legalcode},
	issn = {1939-1404, 2151-1535},
	url = {https://ieeexplore.ieee.org/document/11006264/},
	doi = {10.1109/JSTARS.2025.3570859},
	urldate = {2026-01-17},
	journal = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing},
	author = {Girard, Félix and Kergoat, Laurent and Mainassara, Ibrahim and Wubda, Maxime and Nikièma, Edwige Dayangnéwendé and Touré, Amadou Abdourhamane and Renou, Julien and Vayre, Maxime and Taburet, Nicolas and Picot, Nicolas and Grippa, Manuela},
	year = {2025},
	pages = {14855--14869},
}

@article{boubacar_moussa_escherichia_2025,
	title = {Escherichia coli in the {Niger} {River}: {Links} to environmental variables and anthropogenic activities in {Niamey} city, {Niger}},
	volume = {59},
	issn = {22145818},
	shorttitle = {Escherichia coli in the {Niger} {River}},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S2214581825001521},
	doi = {10.1016/j.ejrh.2025.102328},
	language = {en},
	urldate = {2026-01-17},
	journal = {Journal of Hydrology: Regional Studies},
	author = {Boubacar Moussa, Moussa and Abdourhamane Touré, Amadou and Lartiges, Bruno and Kergoat, Laurent and Robert, Elodie and Mamane, Aliko and Ribolzi, Olivier and Rochelle-Newall, Emma and Grippa, Manuela},
	month = jun,
	year = {2025},
	pages = {102328},
}

@article{wang_surface_2025,
	title = {The {Surface} {Water} and {Ocean} {Topography} {Mission} ({SWOT}) {Prior} {Lake} {Database} ({PLD}): {Lake} {Mask} and {Operational} {Auxiliaries}},
	volume = {61},
	issn = {0043-1397, 1944-7973},
	shorttitle = {The {Surface} {Water} and {Ocean} {Topography} {Mission} ({SWOT}) {Prior} {Lake} {Database} ({PLD})},
	url = {https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023WR036896},
	doi = {10.1029/2023WR036896},
	abstract = {Abstract
            Lakes are among the most prevalent and predominant water repositories on the Earth's land surface. A primary objective of the Surface Water and Ocean Topography (SWOT) satellite mission is to monitor surface water elevation, area, and storage change in lakes globally. To meet this objective, prior information on lakes, such as locations and benchmark extents, is required to organize SWOT's KaRIn observations for computing lake storage variation over time. Here, we present the SWOT mission Prior Lake Database (PLD) to fulfill this requirement. This paper emphasizes the development of the “operational PLD,” which consists of (a) a high‐resolution mask encompassing approximately 6 million lakes and reservoirs that meet the minimum size criterion of 1 ha, as defined in SWOT’s lake observation science goals, and (b) multiple operational auxiliaries that support the lake mask in generating SWOT's standard lake vector data products. We built the prior lake mask by harmonizing the UCLA Circa‐2015 Global Lake Dataset and several state‐of‐the‐art reservoir databases. Operational auxiliaries were produced from multi‐theme geospatial data to provide essential information for PLD functionality, including lake catchments and influence areas, ice phenology, relationship with SWOT prior rivers, and spatiotemporal coverage by SWOT overpasses. Globally, over three quarters of the prior lakes are smaller than 10 ha. About 97\% of the lakes, constituting half of the global lake area, are fully observed at least once per orbit cycle. The PLD will be recursively improved throughout the mission lifetime and serves as a critical framework for organizing, processing, and interpreting SWOT observations over lacustrine environments with fundamental significance to lake system science.
          , 
            Key Points
            
              
                
                  Surface Water and Ocean Topography (SWOT) Prior Lake Database (PLD) provides the foundation for generating SWOT lake vector products including area, height, and storage change
                
                
                  PLD inventories ∼6 million lakes with a 1‐ha minimum size, 76\% of which are smaller than 10 ha and 97\% are fully observed per orbit cycle
                
                
                  PLD contains multiple operational auxiliaries to ease lake assignment, storage change computation, and lake vector data product distribution},
	language = {en},
	number = {3},
	urldate = {2026-01-17},
	journal = {Water Resources Research},
	author = {Wang, Jida and Pottier, Claire and Cazals, Cécile and Battude, Marjorie and Sheng, Yongwei and Song, Chunqiao and Sikder, Md Safat and Yang, Xiao and Ke, Linghong and Delhoume, Manon and Gosset, Marielle and Oliveira, Rafael Reis Alencar and Grippa, Manuela and Girard, Félix and Allen, George H. and Xu, Xiangtao and Zhu, Xiaolin and Biancamaria, Sylvain and Smith, Laurence C. and Crétaux, Jean‐François and Pavelsky, Tamlin M.},
	month = mar,
	year = {2025},
	keywords = {satellite, ressources},
	pages = {e2023WR036896},
	file = {Full Text PDF:C\:\\Users\\cohardj\\Zotero\\storage\\KCLCYGRH\\Wang et al. - 2025 - The Surface Water and Ocean Topography Mission (SWOT) Prior Lake Database (PLD) Lake Mask and Opera.pdf:application/pdf},
}

@article{girard_comparison_2025,
	title = {Comparison of {Methods} to {Derive} the {Height}‐{Area} {Relationship} of {Shallow} {Lakes} in {West} {Africa} {Using} {Remote} {Sensing}},
	volume = {61},
	issn = {0043-1397, 1944-7973},
	url = {https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024WR037411},
	doi = {10.1029/2024WR037411},
	abstract = {Abstract
            In West Africa, lakes and reservoirs play a vital role as they are critical resources for drinking water, livestock, irrigation, and fisheries. Given the scarcity of in‐situ data, satellite remote sensing is an important tool for monitoring lake volume changes in this region. Several methods have been developed to do this using water height‐area‐volume relationships, but few publications have compared their performances over small and medium‐sized shallow lakes. In this work we compare four methods based on recent data from high‐resolution optical imagery and radar and lidar altimetry over 16 lakes in the Central Sahel, with areas between 0.22  and 21 . All methods show consistent results and are generally in good agreement with in‐situ data in terms of accuracy (Root Mean Squared Error below 0.42 m for heights and Normalized Root Mean Squared Error below 13\% for volumes). The precision of the estimated water height is about 0.20 m for Pleiades Digital Surface Models (DSMs) and less than 0.13 m for the other methods. Inherent limitations such as DSM quality, temporal coverage of DSM and lidar data, and spatial coverage of radar altimetry data are identified. Overall, fine shape patterns are consistently observed over small height amplitudes, highlighting the ability to monitor shallow lakes with non‐linear height‐area relationship. Finally, we show that combining lidar and radar altimetry‐based methods provides estimates of volume changes over the different water bodies of the study region accurate enough to monitor seasonal, interannual, and long‐term variability.
          , 
            Key Points
            
              
                
                  Height‐area‐volume relationships of small and medium‐sized shallow lakes are estimated using recent remote sensing data based methods
                
                
                  Radar and lidar altimetry coupled to Sentinel‐2 imagery, and Pleiades Digital Surface Models perform well against in‐situ data
                
                
                  Inherent limits, spatio‐temporal coverage, and data accessibility of each method are identified and discussed},
	language = {en},
	number = {2},
	urldate = {2026-01-17},
	journal = {Water Resources Research},
	author = {Girard, F. and Kergoat, L. and Nikiema, H. and Wubda, M. and Yonaba, R. and Fowé, T. and Touré, A. Abdourhamane and Mainassara, I. and De Fleury, M. and Grippa, M.},
	month = feb,
	year = {2025},
	pages = {e2024WR037411},
	file = {Full Text PDF:C\:\\Users\\cohardj\\Zotero\\storage\\J9H3BUT9\\Girard et al. - 2025 - Comparison of Methods to Derive the Height‐Area Relationship of Shallow Lakes in West Africa Using R.pdf:application/pdf},
}

@article{de_fleury_highly_2025,
	title = {Highly turbid and eutrophic small water bodies in {West} {Africa} well identified by a {CNN} {U}-{Net} algorithm},
	volume = {37},
	issn = {23529385},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S2352938524002763},
	doi = {10.1016/j.rsase.2024.101412},
	language = {en},
	urldate = {2026-01-17},
	journal = {Remote Sensing Applications: Society and Environment},
	author = {De Fleury, Mathilde and Grippa, Manuela and Brandt, Martin and Fensholt, Rasmus and Reiner, Florian and Kovacs, Gyula Maté and Kergoat, Laurent},
	month = jan,
	year = {2025},
	pages = {101412},
}

@article{farhani_spatially_2025,
	title = {Spatially remotely sensed evapotranspiration estimates in {Sahel} region using an ensemble contextual model with automated heterogeneity assessment},
	volume = {11},
	issn = {26660172},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S2666017225000355},
	doi = {10.1016/j.srs.2025.100229},
	language = {en},
	urldate = {2026-01-17},
	journal = {Science of Remote Sensing},
	author = {Farhani, Nesrine and Etchanchu, Jordi and Boulet, Gilles and Gamet, Philippe and Olioso, Albert and Dezetter, Alain and Bodian, Ansoumana and Chahinian, Nanée and Mallick, Kanishka and Ollivier, Chloé and Roupsard, Olivier and Allies, Aubin and Demarty, Jérôme},
	month = jun,
	year = {2025},
	pages = {100229},
}

@article{sauzedde_compound-event_2025,
	title = {Compound-event analysis in non-stationary hydrological hazards: a case study of the {Niger} {River} in {Niamey}},
	volume = {70},
	issn = {0262-6667, 2150-3435},
	shorttitle = {Compound-event analysis in non-stationary hydrological hazards},
	url = {https://www.tandfonline.com/doi/full/10.1080/02626667.2024.2435534},
	doi = {10.1080/02626667.2024.2435534},
	language = {en},
	number = {3},
	urldate = {2026-01-17},
	journal = {Hydrological Sciences Journal},
	author = {Sauzedde, Elisa and Vischel, Théo and Panthou, Gérémy and Tarchiani, Vieri and Massazza, Giovanni and Housseini Ibrahim, Mohamed},
	month = feb,
	year = {2025},
	keywords = {tendances},
	pages = {406--421},
}

@article{akponi_using_2025,
	title = {Using an {Artificial} {Neural} {Network} to {Assess} {Several} {Rainfall} {Estimation} {Algorithms} {Based} on {X}-{Band} {Polarimetric} {Variables} in {West} {Africa}},
	volume = {16},
	issn = {2073-4433},
	url = {https://www.mdpi.com/2073-4433/16/4/371},
	doi = {10.3390/atmos16040371},
	abstract = {Quantitative precipitation estimation using polarimetric radar in attenuation-prone frequency (X-band) in tropical regions characterized by convective rain systems with high intensities is a major challenge due to strong attenuations that can lead to total signal extinction over short distances. However, some authors have addressed this issue in Benin since 2006 in the framework of the African Monsoon Multidisciplinary Analysis program. Thus, with an experimental setup consisting of an X-band polarimetric weather radar (Xport) and a network of rain gauges, investigations have started on the subject with the aim of improving rainfall estimates. Based on simulated polarimetric variables and using a Multilayer Perceptron artificial neural network, several bi-variable and tri-variable algorithms were assessed in this study. The data used in this study are of two categories: (i) simulated polarimetric variables (Rayleigh reflectivity Z, horizontal attenuation Ah, horizontal reflectivity Zh, differential reflectivity Zdr, and specific differential phase Kdp) and rainfall intensity (R) obtained from Rain Drop Size Distribution (DSD) measurements used for algorithm evaluation (training and testing); (ii) polarimetric variables measured by the Xport radar and rainfall intensity measured by rain gauges used for algorithm validation. The simulations are performed using the T-matrix code, which leverages the scattering properties of spheroidal particles. The DSD measurements taken in northwest Benin were used as input for this code. For each spectrum, the T-matrix code simulates multiple variables. The simulated data (first category) were divided into two parts: one for training and one for testing. Subsequently, the best algorithms were validated with the second category of data. The performance of the algorithms during training, testing, and validation was evaluated using metrics. The best selected algorithms are A1:R(Z,Kdp) and A12:R(Zdr,Kdp) (among the bi-variable); B2:R(Zh,Zdr,Kdp) and B3:R(Ah,Zdr,Kdp) (among the tri-variable). Tri-variable algorithms outperform bi-variable algorithms. Validation with observation data (Xport measurements and rain gauge network) showed that the algorithm B3:R(Ah,Zdr,Kdp) performs better than B2:R(Zh,Zdr,Kdp).},
	language = {en},
	number = {4},
	urldate = {2026-01-17},
	journal = {Atmosphere},
	author = {Akponi, Fulgence Payot and Moumouni, Sounmaïla and Zahiri, Eric-Pascal and Kacou, Modeste and Gosset, Marielle},
	month = mar,
	year = {2025},
	pages = {371},
	file = {Full Text PDF:C\:\\Users\\cohardj\\Zotero\\storage\\PDD5TN6C\\Akponi et al. - 2025 - Using an Artificial Neural Network to Assess Several Rainfall Estimation Algorithms Based on X-Band.pdf:application/pdf},
}

@article{le_roux_hydrological_2026,
	title = {Hydrological regime shifts in {Sahelian} watersheds: an investigation with a simple dynamical model driven by annual precipitation},
	volume = {30},
	issn = {1607-7938},
	url = {https://hess.copernicus.org/articles/30/929/2026/},
	doi = {10.5194/hess-30-929-2026},
	number = {4},
	journal = {Hydrol. Earth Syst. Sci.},
	author = {Le Roux, E. and Wendling, V. and Panthou, G. and Dubas, O. and Vandervaere, J.-P. and Hector, B. and Favreau, G. and Cohard, J.-M. and Pierre, C. and Descroix, L. and Mougin, E. and Grippa, M. and Kergoat, L. and Demarty, J. and Rouche, N. and Etchanchu, J. and Peugeot, C.},
	month = feb,
	year = {2026},
	note = {Publisher: Copernicus Publications},
	pages = {929--944},
}

@article{paolini_prism_2024,
	title = {{PrISM} at {Operational} {Scale}: {Monitoring} {Irrigation} {District} {Water} {Use} during {Droughts}},
	volume = {16},
	issn = {2072-4292},
	doi = {10.3390/rs16071116},
	abstract = {Efficient water management strategies are of utmost importance in drought-prone regions, given the fundamental role irrigation plays in avoiding yield losses and food shortages. Traditional methodologies for estimating irrigation amounts face limitations in terms of overall precision and operational scalability. This study proposes to estimate irrigation amounts from soil moisture (SM) data by adapting the PrISM (Precipitation Inferred from Soil Moisture) methodology. The PrISM assimilates SM into a simple Antecedent Precipitation Index (API) model using a particle filter approach, which allows the creation and estimation of irrigation events. The methodology is applied in a semi-arid region in the Ebro basin, located in the north-east of Spain (Catalonia), from 2016 to 2023. Multi-year drought, which started in 2020, particularly affected the region starting from the spring of 2023, which led to significant reductions in irrigation district water allocations in some of the areas of the region. This study demonstrates that the PrISM approach can correctly identify areas where water restrictions were adopted in 2023, and monitor the water usage with good performances and reliable results. When compared with in situ data for 8 consecutive years, PrISM showed a significant person’s correlation between 0.58 and 0.76 and a cumulative weekly root mean squared error (rmse) between 7 and 11 mm. Additionally, PrISM was applied to three irrigation districts with different levels of modernization, due to the different predominant irrigation systems: flood, sprinkler, and drip. This analysis underlined the strengths and limitations of PrISM depending on the irrigation techniques monitored. PrISM has good performances in areas irrigated by sprinkler and flood systems, while difficulties are present over drip irrigated areas, where the very localized and limited irrigation amounts could not be detected from SM observations.},
	number = {7},
	journal = {Remote Sensing},
	author = {Paolini, Giovanni and Escorihuela, Maria J. and Bellvert, Joaquim and Merlin, Olivier and Pellarin, Thierry},
	year = {2024},
	keywords = {remote sensing, soil moisture, data assimilation, PrISM, irrigation estimates},
	pages = {1116},
}

@article{peugeot_evidence_2026,
	title = {Evidence of hydrological regime shifts associated with a major decades-long drought in {West} {Africa}},
	issn = {2041-1723},
	url = {https://www.nature.com/articles/s41467-026-72648-6},
	doi = {10.1038/s41467-026-72648-6},
	language = {en},
	urldate = {2026-06-18},
	journal = {Nature Communications},
	author = {Peugeot, Christophe and Wendling, Valentin and Le Roux, Erwan and Panthou, Gérémy and Hector, Basile and Rouché, Nathalie and Crespin-Boucaud, Arthur and Favreau, Guillaume and Boubé Dobi, Farida and Cohard, Jean-Martial and Demarty, Jerôme and Descroix, Luc and Etchanchu, Jordi and Grippa, Manuela and Hiernaux, Pierre and Ingatan Warzagan, Aghali and Kergoat, Laurent and Malam Abdou, Moussa and Mougin, Eric and Pierre, Caroline and Rajot, Jean-Louis and Vandervaere, Jean-Pierre and Vischel, Théo and Lebel, Thierry},
	month = may,
	year = {2026},
}

@article{tabsoba_how_2026,
	title = {How sustainable land management practices may impact water resources in the {Sahel}: {Insights} from an integrated critical zone modelling approach},
	volume = {66},
	issn = {22145818},
	shorttitle = {How sustainable land management practices may impact water resources in the {Sahel}},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S2214581826005318},
	doi = {10.1016/j.ejrh.2026.103633},
	language = {en},
	urldate = {2026-06-18},
	journal = {Journal of Hydrology: Regional Studies},
	author = {Tabsoba, Mahamadi and Hector, Basile and Cohard, Jean-Martial and Vandervaere, Jean-Pierre and Ingatan Warzagan, Aghali and Peugeot, Christophe and Lawin, Agnidé Emmanuel},
	month = aug,
	year = {2026},
	pages = {103633},
}

@article{ba_drivers_2026,
	title = {Drivers and vertical {CO}$_{\textrm{2}}$ flux balances in a {Sahelian} agroforestry system: {Insights} from high frequency measurements},
	volume = {12},
	copyright = {https://creativecommons.org/licenses/by/4.0/},
	issn = {2199-398X},
	shorttitle = {Drivers and vertical {CO}$_{\textrm{2}}$ flux balances in a {Sahelian} agroforestry system},
	url = {https://soil.copernicus.org/articles/12/471/2026/},
	doi = {10.5194/soil-12-471-2026},
	abstract = {Abstract. Agroforestry systems – combining trees with crops and/or livestock – are increasingly promoted as sustainable and climate-resilient land-use strategies. Despite their widespread presence in the Sahel, experimental data on their potential as carbon sinks are scarce. This study presents a full-year, high-frequency dataset of CO2 fluxes in a Sahelian agro-silvo-pastoral parkland dominated by Faidherbia albida, located in Senegal's groundnut basin. CO2 fluxes were continuously measured using automated dynamic chambers, allowing the quantification of soil and crop respiration (Rch), gross primary production (GPPch), and net carbon exchange (FCO2ch) under both full sun and shaded (under tree canopies) environments. Seasonal patterns of CO2 fluxes were similar in both environments, with peaks during the rainy season. Rch and GPPch were significantly higher under tree canopies, indicating a “fertile island” effect. CO2 flux variability was primarily driven by soil moisture and leaf area index. Chamber-based GPP estimates closely matched those from Eddy Covariance measurements. On an annual scale, F. albida trees contributed approximately 23 \% of total ecosystem GPP, with a carbon use efficiency of 0.48. Net annual vertical CO2 exchange was estimated at −1.4 ± 0.46 and −1.8 ± 0.17 Mg C-CO2 ha−1 using chamber and Eddy Covariance methods, respectively. These findings underscore the role of F. albida-based agroforestry systems as effective carbon sinks in Sahelian landscapes, supporting their potential contribution to climate change mitigation.},
	language = {en},
	number = {1},
	urldate = {2026-07-02},
	journal = {SOIL},
	author = {Ba, Seydina M. and Roupsard, Olivier and Chapuis-Lardy, Lydie and Bouvery, Frédéric and Agbohessou, Yélognissè and Duthoit, Maxime and Wieckowski, Aleksander and Tagesson, Torbern and Assouma, Mohamed H. and Gaglo, Espoir K. and Delon, Claire and Sambou, Bienvenu and Serça, Dominique},
	month = apr,
	year = {2026},
	pages = {471--495},
	file = {Texte intégral:C\:\\Users\\cohardj\\Zotero\\storage\\SISUDDMN\\Ba et al. - 2026 - Drivers and vertical CO2 flux balances in a Sahelian agroforestry system Insights from h.pdf:application/pdf},
}

@article{gaglo_sensitivity_2025,
	title = {Sensitivity of a {Sahelian} groundwater-based agroforestry system to tree density and water availability using the land surface model {ORCHIDEE} (r7949)},
	volume = {18},
	copyright = {https://creativecommons.org/licenses/by/4.0/},
	issn = {1991-9603},
	url = {https://gmd.copernicus.org/articles/18/9541/2025/},
	doi = {10.5194/gmd-18-9541-2025},
	abstract = {Abstract. The Sahel region is characterized by its semi-arid climate and open-canopy agroforestry systems, which play an important role in global carbon dynamics. Parkland agroforestry has the potential to sequester carbon at an average rate of 0.4 tC ha−1 yr−1, which, if expanded to its maximum potential extent, would correspond to an additional carbon stock of approximately 558 TgC compared to treeless croplands. However, land surface models (LSM) used in global climate modeling struggle to represent carbon dynamics in these ecosystems due to the inadequate representation of deep-roots tapping groundwater during dry periods, key environmental control for many agroforestry systems such as the widespread parklands based on the phreatophytic species Faidherbia albida. This study explores the sensitivity of Faidherbia albida parklands to tree density and water availability (rainfall and soil water content in the capillary fringe of the groundwater table) using a new configuration of the ORCHIDEE LSM. To this aim, the ORCHIDEE LSM was modified to simulate the growth of Faidherbia albida by simulating its inverted phenology based on forced temporal series of soil water content of soil layers between 4 and 5 m and water saturation below 5 m and by adjusting the photosynthesis and carbon allocation parameters for Faidherbia albida and associated crops. The model was evaluated against independent eddy covariance and meteorological data from the Niakhar agroforestry site in Senegal. Simulation outputs were analyzed in terms of leaf area index (LAI), gross primary productivity (GPP), latent heat (LE), sensible heat (H) and net radiation (Rn). The model simulated tree GPP of 4.08 ± 0.21 tC ha−1 yr−1 compared to observed GPP of 5.06 ± 0.49 tC ha−1 yr−1. For croplands, the model produced GPP of 7.97 ± 0.89 tC ha−1 yr−1 compared to observed values of 7.78 ± 1.75 tC ha−1 yr−1. Simulations revealed that tree density positively influenced annual carbon uptake but reduced crop harvest at highest tree densities, indicating a trade-off between carbon sequestration and crop yield. Sensitivity analyses showed that interannual variability in soil water content in the capillary fringe of the groundwater table and rainfall influenced differently crop, tree and ecosystem carbon and energy fluxes. Despite its strengths, the model exhibited limited responsiveness of tree productivity to soil water content variability in the capillary fringe of the groundwater table, highlighting the need for enhanced representation of water uptake by tree roots in the model. These findings emphasize the importance of accurately modeling both surface soil water and groundwater dynamics and phenology to predict the responses of semi-arid agroforestry systems to climate variability. This study enhances our understanding of carbon and energy flux partitioning in complex, water-stressed and groundwater dependent agroforestry systems.},
	language = {en},
	number = {23},
	urldate = {2026-07-02},
	journal = {Geoscientific Model Development},
	author = {Gaglo, Espoir Koudjo and Chaste, Emeline and Luyssaert, Sebastiaan and Roupsard, Olivier and Jourdan, Christophe and Sow, Sidy and Vandewalle, Nadeige and Do, Frédéric C. and Ngom, Daouda and Valade, Aude},
	month = dec,
	year = {2025},
	pages = {9541--9563},
	file = {Texte intégral:C\:\\Users\\cohardj\\Zotero\\storage\\N5BY6NFN\\Gaglo et al. - 2025 - Sensitivity of a Sahelian groundwater-based agroforestry system to tree density and water availabili.pdf:application/pdf},
}

@article{issoufou_ousmane_groundwater_2023,
	title = {Groundwater quality and its implications for domestic and agricultural water supplies in a semi-arid river basin of {Niger}},
	volume = {82},
	issn = {1866-6299},
	url = {https://doi.org/10.1007/s12665-023-11016-9},
	doi = {10.1007/s12665-023-11016-9},
	abstract = {In the River Goulbi Maradi Basin (RGMB), groundwater is a vital source of drinking water and plays a central role in the region’s socio-economic development. The quality and suitability of groundwater for irrigation and drinking-water remain inadequately understood. We examine hydrochemical analyses of 35 groundwater samples from the shallow alluvial (17) and underlying Continental Hamadien (CH) sandstone (18) aquifers and evaluate these against standard measures of their suitability for drinking water (World Health Organization (WHO) guideline values) and irrigation (i.e., sodium adsorption ratio, sodium percentage, and the residual sodium carbonate). Hydrochemical facies are principally of Na–HCO3 and Na–Cl types. Bivariate plots combined with saturation indices and electrical conductivity monitoring suggest that the main hydrogeochemical processes influencing groundwater quality are cation exchange in the CH aquifer and solute leaching from soils during focused recharge in the alluvial aquifer. 76\% (13/17) of groundwater samples from the alluvial aquifer were suitable for irrigation compared to 38\% (6/16) of the samples from the CH. The identification of high fluoride concentrations exceeding the WHO drinking-water guideline value ({\textgreater} 1.5 mg/L) in 33\% (6/18) of samples from the CH aquifer and 18\% (3/17) in the alluvial aquifer, and their respective attribution to the release of fluoride of geogenic origin through cation exchange and local use of fluorapatite fertilisers, provide valuable insight into efforts to address the on-going challenge of fluorosis in the Maradi region of Niger and more widely across African drylands. The health consequences of the widespread observation of Mn in concentrations exceeding the new WHO guideline value (0.08 mg/L) in the alluvial aquifer (6/9 samples), often alongside elevated Fe concentrations, are unclear.},
	number = {13},
	journal = {Environmental Earth Sciences},
	author = {Issoufou Ousmane, Boukari and Nazoumou, Yahaya and Favreau, Guillaume and Abdou Babaye, Maman Sani and Abdou Mahaman, Rabilou and Boucher, Marie and Sorensen, James P. R. and MacDonald, Alan M. and Taylor, Richard Graham},
	month = jun,
	year = {2023},
	pages = {329},
}