Morphometric analysis is vital to prioritize sub-watershed for flood hazard assessment in drainage basins for proper planning and management of natural resources for sustainable development. The present study was aimed to assess flash flood hazards and prioritize sub-watersheds in the Heliopolis basin, East Cairo, Egypt. Shuttle Radar Topographic Mission (SRTM) with 90 m resolution DEM has been used to generate drainage networks and delineation of sub-watersheds. This basin has been classified into ten sub-watersheds; three groups of morphometric parameters: basic, derived, and shape parameters were measured and calculated quantitatively using Arc GIS and WMS10.1 package. The morphometric hazard degree assessment method has been employed to generate a flooding risk susceptibility map. Results reveal that W. Al-Nasory Al-Kabir constituting 24.74% of the total area has a “high hazard degree”, and thus represents dangerous sub-basins with high flooding susceptibility, whereas the susceptibility of the other sub-watersheds has been found as “moderate” [W. El Forn trunk, W. Al-Aqabia, W. El-Halazony, W. Al-Debah, W. Al-Yahmoum, and W. Al-Monaqee (62.03%)], and “slight hazard” [W. Abu Dorma, W. El-Daltan, and W. Elwiat El-Widian (13.23%)]. Ten morphometric parameters have been selected and used for ranking and prioritizing sub-watersheds to detect the most vulnerable sub-watershed to soil erosion and to generate a flooding priority map. In this regard, W. Al-Aqabia, El -Forn trunk, W. El-Halazony, W. Al-Yahmoum, W. Al-Nasory Al-Kabir, and W. Al-Debah sub-watersheds have been catego rized into higher priorities. Therefore, these sub-watersheds are relatively affected by runoff and soil erosion. The obtained results can help decision-makers to understand flooding risk susceptibility in the different sub-watersheds in the study area and this led to better management to avoid flood risk disasters. |
