Global Research Journal of Geography

ISSN 2360-8005

Morphometric analysis of Gojeb river sub basin around South Western part of Ethiopia by using GIS and remote sensing


Abstract: Morphometry is the science of measuring and analyzing the patterns and dimensions of landforms on the Earth's surface. By conducting a morphometric analysis of a river basin, one can obtain a quantitative description of its drainage system, which is crucial for understanding and characterizing the basin. This study employed ARCGIS and image processing techniques to identify and analyse the morphological features and basin characteristics of the Gojeb watershed. By using GIS hydrology tools, watersheds were delineated and analysed based on DEM data. The analysis revealed several important drainage parameters: The largest stream order is five, with a bifurcation ratio of 4.62. The total stream length is 191.9 km, and the drainage pattern is dendritic. The basin covers an area of 4405.5 km2, with a form factor of 0.74, indicating an elongated shape. The circularity ratio is 0.25, and the drainage density is 0.04, suggesting porous lithology with high infiltration capacity. Additionally, the stream frequency is 0.12, indicating high humidity, and the overland flow value is 11.5, indicating a very coarse drainage texture. Consequently, the basin is susceptible to groundwater pollution through infiltration and percolation. The morphometric parameters suggest low runoff rates and very high infiltration rates, which indicate the presence of geological structures such as faults, fractures, and porosity that facilitate infiltration and percolation.

 

Keyword: GIS, Gojeb River, morphometric parameter, remote sensing