Delineating flood hazards using the interpreted structural setting and GIS in Attaif, western Saudi Arabia

Attaif is one of the most flooded areas in the Kingdom of Saudi Arabia due to its topography, being located at the eastern coast of the Red Sea. In the present study, we used the aeromagnetic data and the GIS techniques in order to understand the behaviour of the flood and its relation to geological structures. The aeromagnetic data can be used for mapping tectonic features, geologic contacts, and structures of the buried basement terrain. The structural lineaments (e.g. faults, which cause the formation of major basins) were deduced from magnetic maps. The basin trends reflect the structural elements that control the drainage of flood towards the basins and sub-basins. In the study, a direct relationship between the lineament features and the drainage streams was found. Besides, the database of the geological features was built using GIS capabilities. The geomorphic characteristics of a drainage basin represent a significant function in controlling the basin’s hydrology. The hydrologic data was extracted from the DEM data by using the flow accumulation grid tool. Moreover, the spatial distribution of drainage basins and the morphometric analysis was achieved by using the ArcGIS software. Besides, the evaluation of different morphometric parameters represented the land’s topographic expression. The results revealed that Attaif is crossed by three major flood basins, which are controlled by deep geological structures.