Mapping flood vulnerability using hydrologic modeling and GIS-based morphometric analysis

The most frequent kind of natural disasters is flash flooding, which happens when too much water floods normally dry areas. Flash Floods can inflict extensive destruction, including loss of life, damage to private property, and destruction of vital infrastructure. Therefore, this scientific research aims to study all the factors that affect these floods and conduct the necessary hydrological studies of Wadi El Assiuti depending on hydrological indicators and morphometric analysis to assess flash flood risk. Thirty-six parameters are calculated and are put into four categories (drainage texture, drainage network, relief characteristics, and basin geometry). The following ten indices are chosen: Precipitation (P), Elevation (ELEV), Slope (SL), Drainage density (Dd), Terrain Ruggedness Index (TRI), Stream Power Index (SPI), Sediment Transport Index (STI), Topographic Wetness Index (TWI), Topographic Position Index (TPI), and Normalized Difference Vegetation Index (NDVI). According to each index's proportional importance, it is weighted by applying the Analytical Hierarchy Process (AHP) technique. The Wadi El Assiuti occupies an area of (6045.57 Km2). The wadi, which consists of 926 streams having 3326.82 kilometers in length, is associated with the 6th order. After the map is created, it explains that nearly 45.5% of the wadi is ranked as regions of high and very high danger, and 30.3% as regions of moderate danger. While almost 24.1% of the Wadi is classified as low and very low. This study can be beneficial for decision-makers and local authorities who want to implement mitigation measures to alleviate the danger of flash floods, like the floods of Darinka village on November 2, 1994.