Community-Level Flood Risk Assessment and Mapping in the Lower Ouémé River Basin, Benin

Understanding and mapping community vulnerability to hydroclimatic risks are critical prerequisites for effective flood disaster management and resilience planning. This study applies the IPCC AR5 framework to assess and map flood risk across 86 villages in the Lower Ouémé Valley (BVO), Benin, with the goal of spatializing risk levels to better inform local adaptation and decision-making. An integrated approach combining participatory diagnosis and spatial modeling was adopted. Data were collected at the community level using KoboCollect, and a set of indicators representing the three components of risk—hazard, exposure, and vulnerability were developed, normalized, and weighted according to the AR5 framework. Thematic maps were then generated in QGIS to visualize spatial variations in risk. The results indicate that approximately 72% of the villages face medium to very high levels of flood risk, reflecting significant disparities associated with flood duration, water depth, population density, and poverty index. The most affected zones require priority attention for the implementation of early warning systems and adaptive response strategies. Only 10% of the surveyed villages currently possess hydrological monitoring devices, while local risk perception remains predominantly based on indigenous knowledge. These findings emphasize the need for territorialized climate risk governance grounded in participatory and scientifically validated mapping approaches. The study proposes a replicable methodology for spatial flood risk assessment that operationalizes the IPCC AR5 conceptual framework at the local scale. Future work could enhance this approach through dynamic risk modeling and the integration of high-resolution satellite data to improve the spatial and temporal accuracy of flood risk prediction.