Model representation of the Sudanian hydrological processes: Application on the Donga catchment (Benin) M. Le Lay a,c, * , G.-M. Saulnier b,c , S. Galle c , L. Seguis d , M. Me´tadier d , Ch. Peugeot d a EDF-DTG, Centre Hydrome´te´orologique Alpes, 41 av. de l’Europe, BP41, 38040 Grenoble cedex 09, France b EDYTEM, UMR 5204, Universite´ de Savoie, FR-73376 Le Bourget du Lac Cedex, France c LTHE, UMR 5564 (CNRS, UJF, INPG, IRD), Domaine Universitaire, BP 53, 38041 Grenoble Cedex 9, France d Hydrosciences Montpellier, UMR 5569, 34095 Montpellier Cedex 5, France Received 22 February 2008; received in revised form 17 September 2008; accepted 28 September 2008 KEYWORDS Hydrological modelling; West Africa; Multi-criteria evaluation Summary During the AMMA (African Monsoon Multidisciplinary Analysis) program, inten- sive field experiments were conducted on the Donga catchment (586 km 2 ), which is part of the Oue´me´ surveyed hydrological watershed (14,400 km 2 ). Based on these studies, a num- ber of general hydrological assumptions were derived to explain the hydrological function- ing 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 param- eterization of evapotranspiration was added to the model. This paper details this modeli- sation 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 repre- sentation 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 0022-1694/$ - see front matter ª 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.jhydrol.2008.09.006 * Corresponding author. Present address: EDF-DTG, Centre Hydrome´te´orologique Alpes, 41 av. de l’Europe, BP41, 38040 Grenoble cedex 09, France. Tel.: +33 4 76 20 23 54. E-mail address: matthieu.le-lay@edf.fr (M. Le Lay). Journal of Hydrology (2008) 363, 32– 41 available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/jhydrol