Flood Risk Analysis in the Sub-Basins of Wadi Al-Qattara Using Morphometric and Hydrological Indices

Abstract

This study analyzed flood risks in the sub-basins of Wadi Al-Qattara Basin through the integration of morphometric and hydrological indicators, aiming to analyze basin characteristics, estimate surface runoff and discharge, and classify flood risk levels. The study adopted a historical approach to analyze annual rainfall at Benina Station during the period 1980–2000, a comparative approach to examine the areal, geometric, and relief characteristics of the basins, in addition to quantitative analytical, statistical, and cartographic methods using ArcMap 10.8. The results revealed significant variations in the hydrological response among the sub-basins. The time of concentration ranged from 2.54 to 11.83 hours, with the Qattara Basin recording the highest value and the Sidr Basin the lowest, indicating differences in the response time of the basins to surface runoff. The lag time ranged from 1.52 to 7.10 hours, while the average discharge ranged from 491.10 to 2,178.31 m³/s, with the Sidr Basin recording the highest value and Bousheiwa Basin the lowest. Drainage density also varied considerably, ranging from 3.67 to 26.30, reflecting differences in surface characteristics and drainage-network development, and consequently variations in flood risk levels among the sub-basins.