Assessing the Safety of Settlements from Flood Risk

Abstract

The fact that Egypt falls within the arid and semi-arid areas, makes it always vulnerable to sudden storms, which have increased significantly during the past ten years. Climate change is one of the factors that cause the increasing of the sudden storms frequency, intensity and expansion to cover new areas. During three days, from November 11 to 13, 2021, a severe storm hit the city of Aswan and its suburbs, leaving behind extensive property damage and loss of life. Where heavy rains, fell in a short time, on the Eastern Desert Mountains led to torrential rains (flash flood) that flowed to the plains through the paths of the valleys, causing severe damage to several villages, which are located in the hydrologically active valleys (Al-Heita, Al-Kimab, Umm Buirat and Abu Al-Rish Qebli). In this paper, the November 2021 storm will be analyzed using Global Precipitation Measurement (GPM) data, with temporal and special resolution of 30 minutes and 0.1° respectively. The data will give a distribution of the storm for each 1 hour during the storm for three days. The amount of water and its velocity will also be simulated using the (HEC-HMS) hydrological model. In addition, the (HEC-RAC) model is used in order to simulate the distribution and expansion of the flood during the storm time step. The results provide an actual simulation of what happened during the 2021 storm. In addition, this model is applied again with the highest values to produce the worst scenario. The final part of this paper highlights the value of this model as a supportive tool for urban planning to achieve sustainability. So, both results of the simulation and the worst scenario were compared to the development plan of the study area. Then, the suitable planning recommendations were accordingly suggested for the areas at risk to ensure sustainable future development.