dataset, converting AutoCAD files to GIS shapefiles, unifying the spatial reference frames for all datasets, performing statistical
and spatial analyses, and flood computations (Al-Ghamdi et al. 2012b). The Arc GIS software has been used to obtain
several shapefiles describing the geomorphology of the study area. These shapefiles include: the main basins and the subbasins of each main catchment, along with drainage network using the Strahler method (a simple widely utilized network order method), and the longest stream path in each catchment. The second stage of the developedmethodology is based on the flood assessment method developed by the NRCS, formerly known as the Soil Conservation Service. Processing steps, and hence attained results, have been performed for past (1990), present (2010), and future (2030) scenarios.