Detailed morphometric characteristics of the catchment area were derived from the analysis of the 30 m resolution ASTER DEM (ASTER GDEM Validation Team 2011). ArcGIS-10, Arc-Hydro (ESRI Inc. 2012), and the correlated Topographic Parameterization Program (TOPAZ) of WMS-8.3 (2010) were used for the integrated analysis of the catchment involving the correlation and verification of topographic maps and DEM. These analyses were carried out to determine the spatially distributed time-area zones of the catchment to simulate the runoff hydrographs under different projected return periods for future storms over the long term. Various methods for channel network delineation and characterization were conducted, including DEM reconditioning, flow accumulation, flow direction, stream definition, sub-catchment definition, DEM slope, and others (Figures 4(a)–4(f)). The raw DEM sinks were removed before being used in hydrological modeling (Mark 1984; Wise 2000). The flow direction was computed by calculating the steepest slope towards the surrounding cells. This flow direction was used to generate the flow accumulation map, which was used to delineate the stream networks to the outlets of the basin. Different threshold values proposed by Djokic et al. (1997) were examined to correct the generated flow lines with the actual network using the Landsat-8 and SPOT-5 images verification. The fourth order of the main wadi trunk was computed to attain the hydrologic analysis of the main basin (Figure 4(f)), while the morphometric parameters of the third order sub-basins were estimated to assess the flooding potentialities at this order level, since several small retardation dams could be proposed (Table 1 and Figure 4(g)).