Analyzing urban watersheds morphometric in arid and semiarid regions using the complementarity of RST and GIS

Abstract

Water is the lifeblood, and additionally is a vital significant strategic resource for human life. However, it has become a rare element menacing human lives at its present state as well as its future eras. The disparity of water distribution leads to a water surplus in several regions and a deficit in others. Therefore, water resources have a precious element that needs to be managed wisely due to benefits for humanity. This study employed the digital elevation model (DEM) of the shuttle radar topography mission (SRTM) for analyzing the Riyadh metropolitan area morphometric parameters (MPs). Generally, the present work covered the various morphometric analysis aspects, which involve linear, areal, and relief parameters. The morphometric analysis (MORA) findings exposed that the main basin delineated into 40 watersheds and has an eighth order with total area 8500 km2. The statistical analysis revealed that there is a negative relationship between stream order and stream number with a coefficient of determination (R2 = 99%). Meanwhile, there is a direct relationship between stream order and cumulative stream length with the same R2 value. Furthermore, most watersheds have a high bifurcation ratio, referring to have impermeable rocks with a steeper slope. Thus, the bifurcation ratio value is in conformity with a high drainage density value of the main basin (1.57 km/km2) and confirm the subsurface material impermeability and mountainous relief. The main basin hypsometric integral (HI) is 38%, while the erosion integral (EI) value is 62%, where both values indicate that the basin is at a mature stage.