Morphometric Analysis of the Western Wadi Al-Boun Basin in Amran Governorate and its Hydrological Indicators Using Geographic Information Systems

Abstract

The study aimed at analysis the morphometric characteristics of the Western Wadi Al-Boun Basin and highlighting its hydrological indicators. As well as building a digital database using Geographic Information Systems and relying on the Digital Elevation Model and standard mathematical equations The Western Wadi Al-Boun Basin is one of the seasonal runoff valleys that are famous for agriculture in the Amran Governorate, covering an area of approximately (193km²). Through hydrological analysis of the study area within a (GIS) environment and the application of morphometric mathematical equations, the study concluded that the basin tends to have a rectangular shape with an asymmetrical perimeter. The circularity ratio, elongation ratio, form factor, and compactness coefficient were found to be (0.40, 0.63, 0.32, 1.57) respectively, indicating hydrologically a medium surface runoff velocity and high water loss, which reduces the significance of flooding in the region. The basin is characterized by high slope and ruggedness, with a ruggedness index of (25.10 m/km). The hypsometric integral and ruggedness values suggest that the basin is in the early stages of its erosional cycle. The analysis of the drainage network indicated that the basin is of the fifth order, consisting of (395) streams with a total length of (349.3 km). The bifurcation ratio was (3.44), indicating a low drainage density. The values for linear drainage density, stream frequency, and stream maintenance were (1.80 km/km², 2.04 streams/km², 0.55 km²/km) respectively, reflecting the influence of climatic factors, rock type, and vegetation cover on the basin's morphometric characteristics