CARACTERISATION DES ZONES A RISQUE D’INONDATION DANS LA COMMUNE D’ATHIEME (SUD-OUEST BENIN)

Abstract

In recent decades, the world has been confronted with a phenomenon of climatic variability marked by cyclical floods that threaten populations and property. Like the large municipalities of Benin, the municipality of Athiémé suffers from flooding due to extreme rainfall and especially from the overflow of the Mono River. The objective of this study is to map the areas at risk of flooding in the municipality of Athiémé. The methodological approach consisted of integrating into a geographic information system (GIS), data interpreted from Landsat OLI images, hydro-climatic data and products derived from a digital elevation model (DTM). The cartographic processing was done using the ArcGis 10.4 software. The reclassification and combination of the various factors related to the floods made it possible to obtain the hazard and vulnerability maps. These maps have four classes ranging from low to very high risk of flooding. The results of the flood risk mapping show that the low and medium risk areas cover 24.27% and 24.48% of the Municipality respectively, the high-risk areas occupy 30.54% of the total area of the Municipality. The very high-risk areas are located in the immediate vicinity of watercourses and occupy 20.70% of the municipality. This risk map is a useful decision-making tool to prevent and effectively manage the risk of flooding in the Commune of Athiémé (South-West Benin).