Application of Geographic Information Systems in Reducing The Risk of Flash Floods. Case Study Wadi Ghareb, Gulf of Suez, Egypt

Egypt faces a deficit in water resources, making the efficient utilization of rainfall water essential. The country is frequently subjected to flash floods due to climate change, which, while causing damage to infrastructure, property, and loss of life, also presents an opportunity for harvesting runoff from these floods. This study employs GIS software to analyze various layers, including Digital Elevation Models (DEM), landforms, geological settings, watershed characteristics, slope, flow directions, and flow accumulation. Ras Ghareb City has experienced significant rainfall storms recently, including notable events in December 2010 (60.48 mm), October 2016 (38.9 mm), and January 2022 (39.8 mm). The December 2010 storm, which resulted in extensive damage in the area, has been selected for analysis. The runoff volume for Wadi Ghareb reached approximately 7035.7 *1000m ³ . The return period for such storms is estimated to be 72 years, with a probability of occurrence of 1.35%. To mitigate the hazards associated with flash floods, several storm water management strategies are recommended, including the installation of culverts beneath asphalt roads to provide protection, the construction of detention dams to reduce flood velocities and facilitate shallow aquifer replenishment, and the use of boulder dams built without cement to allow water to flow naturally.