Multi-criteria decision-making for the analysis of flash floods: A case study of Awlad Toq-Sherq, Southeast Sohag, Egypt

Abstract

The multi-criteria method is a widely used technique to study and analyze the impact and causes of natural hazards. Our study area, that forms a part of the governorate of Sohag, lies in Southeast Sohag and is one of the most flash flood prone regions of Egypt's Eastern Desert. In the last decades, this area of Sohag has suffered from frequent flash floods, with some flood events resulting in human casualties. In our study, we use a multi-criteria process combined with geographical information system (GIS) and remotely sensed data to produce a flash flood susceptibility map. In addition, we discuss the various factors related to flash flooding such as elevation, slope, drainage network, lithology, topographic wetness index, as well as land use, and reclassify these based on their contribution and their effect on flood probability. To calculate the weighted factor for each raster, a pairwise matrix was constructed. Results from our multi-criteria analysis for flash flooding indicate that approximately 5% of the total study area is at a very high risk of flooding, 10% at a high risk, and 25% at a moderate flood risk. Furthermore, our results highlight the areas at risk of flooding and the need for the development of relevant warning systems. Our results also indicate that the southeastern part of the study area is most susceptible to flash floods and we suggest that the necessary focus be given to this region as well as the implementation of a flood warning system. A consistency index was used to determine the accuracy of our model and was calculated to be 0.058, indicating a well-performing model.