Flash flood hazard in Zambia: a data-Driven approach to identifying vulnerable sub-basins

Flash floods pose an increasing threat to lives, infrastructure, and livelihoods in Zambia. This study presents the development of a Flash Flood Prone Areas Map. Using geomorphological, hydrological, and environmental indicators, the research evaluates flash flood hazards across 2,236 sub-basins, in the Kafue, Kariba, Luangwa and Tete basins in Zambia based on data from HydroATLAS-Zambia, the Zambian Soil Map, SRTM DEM, and ESA WorldCover, among others. A Flash Flood Hazard Index (FFHI) was developed through a weighted scoring system informed by expert pairwise ranking from institutions such as the Zambia Agricultural Research Institute, the Water Resources Management Authority, the Disaster Management and Mitigation Unit, and the University of Zambia. Key factors include land cover, slope, basin relief, rock type, soil erosion, and drainage density. The final map serves as a critical tool for disaster risk management, enabling early warning systems, strategic planning, and targeted interventions in high-risk areas.