Hydrological analysis and flood mitigation at Wadi Hadramawt, Yemen

The current research aims at studying the runoff of Wadi Hadramawt employing mathematical models which comprise several methodologies. Moreover, flood damage mitigation structure was designed in accordance with the study outputs in order to mitigate flood risks. To achieve the research aims, data on precipitation, geological map, soil type, and land use were collected from the Yemen General Authority for Meteorology and Yemen Surveying Authority. A digital elevation model (DEM) is used for topographic maps. Frequency analysis techniques for maximum 25-, 50- and 100 years return period rainfall probability for Wadi Hadramawt were determined. The watershed modelling system (WMS) software package was used to delineate Wadi Hadramawt catchment and divide the catchment into eight sub-catchments. HEC-HMS software package was used to estimate the flood hydrographs for the eight sub-catchments. From the hydrological studies, dam structures at two sub-catchments were found essential to mitigate the flood risks in Hadramawt zone.