The precise estimation of surface runoff from rainfall is critical for water resource management. In the recent past, remote sensing and Geographic Information System (GIS) technologies have been widely used in the estimation of surface runoff from watersheds, and from agricultural fields in particular. This is due to the inherent ability of remote sensing to capture spatial heterogeneity of surface parameters such as land use and land cover. This could lead to better performances of surface runoff simulation models.

In the Senegal river floodplain, irrigated agriculture and traditional flood recession crops (mainly sorghum) coexist. The latter depends upon the extent of the annual flood, which is partly a function of the amount of water released from the upstream Manantali reservoir. Even though recession sorghum yield is clearly smaller than that of irrigated rice, this production system, because it covers a large area, is a major contributor to total food production in Podor and Matam departments. It is therefore important to quantify areas and yields.