Assessment and Mapping of Multi-Hazard Risk for Decision Support in the Kedougou Region, Senegal (1995–2024)

The Kedougou region (Senegal) is facing a resurgence of major climatic hazards (droughts, floods, forest fires, and extreme heat) that threaten its population, ecosystems, and sustainable development. This study proposes an integrated method for multi-risk assessment and mapping, combining large-scale analysis of satellite data (Landsat, MODIS, and SRTM) via Google Earth Engine (GEE) with a hierarchical multi-criteria approach (AHP). The method is supported by participatory surveys conducted with key local institutions to reflect local priorities and territorial expertise. Hazards were mapped over three periods (1995–2004, 2005–2014, and 2015–2024) using specific spectral indices: NBR for forest fires, VHI for drought, MNDWI for floods, and LST for extreme heat. Vulnerability is quantified using socio-economic (population density, cultivated areas), environmental (forests), and physical (urbanisation, topography) indicators. Individual risks, calculated as the product of normalised recurrent hazards and normalised vulnerability, were aggregated into a weighted multi-hazard map validated by a Consistency Ratio (CR) of 0.08. The results reveal that 2908.2 km2 (17.2% of the Kedougou region) are exposed to multi-hazard risk, affecting approximately 33,889 people (13.5% of the population of Kedougou) and 18.9 km2 of agricultural land. High-risk zones cover 76.1 km2 and are concentrated in the Saraya department, where mining and population growth exacerbate exposure. Forest fires and floods are identified as the most critical risks. Publication on the MapX platform provides a proactive decision support tool aligned with SDGs 2, 11, 13, and 15. This methodology is adaptable to other semi-arid Sahelian regions facing similar challenges.