Assessment of Flash-Flood Hazard in Arid Watersheds of Jordan

Abstract

Flash flood hazard initiated by heavy rainstorms is common in arid Jordan, and often has induced immense damage to life and infrastructures. The current study presents a flash flood assessment for Wadi Rajil (northern Jordan) and Wadi Wuheida (southern Jordan) watersheds using ASTER DEM, GIS, and geomorphic field observation. A total of 23 morphometric parameters of paramount relation to flash flood risk estimation were extracted and calculated using ASTER DEM, GIS, and mathematical formulae developed for this purpose. Two methods were employed to assess flash floods and to generate flooding risk susceptibility maps. The first method is El-Shamy's approach, and the second is the morphometric hazard degree assessment method. Consequently , sub-basins with high and extreme flooding susceptibility were de-marcated and displayed spatially using GIS. The maps so produced are meant to help planners and decision makers to devise appropriate plans to mitigate harmful flooding impacts, and to deal with flooding hazards.