Deadline for manuscript submissions: 30 September 2024.
The Kayanga-Anambé watershed, located in Haute-Casamance (Senegal), is a strategic area for national food security, yet remains exposed to recurrent flooding that threatens hydro-agricultural developments. This study aims to map flood-susceptibility zones using an integrated approach combining Geographic Information Systems (GIS) with a multi-criteria model built on seven (7) parameters: Flow Accumulation, Rainfall Intensity, Land Use, Geology, Slope, Terrain Elevation, and Distance to drainage (FIGUSED). The methodology relies essentially on cross-referencing morphometric factors (slope, drainage density), climatic factors (rainfall intensity), and anthropogenic factors (land use, infrastructure). Data derived from digital elevation models and Sentinel-2 imagery were processed through an Analytic Hierarchy Process (AHP) to weight the influence of each parameter. The results highlight a strong susceptibility of the Anambé basin, exacerbated by gentle slopes and the rapid saturation of hydromorphic soils during monsoon peaks. The high-susceptibility zone (high and very high classes) totals 40.64% of the watershed area, that is 1257.46 km2, corresponding geographically to the Anambé basin and the floodplain of the Kayanga and its tributaries. The most represented class is high susceptibility, at nearly 28%, closely followed by moderate susceptibility at 25.52% of the total area, indicating an overall heightened susceptibility of the watershed to inundation. The resulting susceptibility map thus constitutes an essential decision-support tool for planning agricultural campaigns through SODAGRI and for protecting human settlements in tropical rural areas.