The objective of this study is to better understand the functioning of a river system in the context of sustainable management of water resources. To better understand this functioning, hydrogeological modelling of the watershed of White Bandama is necessary. The methodological approach is derived from a process comprising two steps. The results are derived from a process comprising two steps. The first step consists in the mapping of the physical descriptors of the watershed that affect hydrological processes, such as topography, drainage patterns, land cover and soil type. Using PHYSITEL and a Digital Elevation Model (DEM), slope and orientation maps of the facets are derived and then coupled to the water system for the characterization of the internal hydrographic structure of the watershed. Supervised classification of Landsat TM dating from 1987 to 1993 led to the mapping of land use. The second step consists in combination of established thematic maps. The combination of these thematic maps is used to determine with HYDROTEL the dominant type of soil and land use by Relatively Homogeneous Hydrological Units (RHHU) representing small sub-watersheds.