MORPHOMETRIC ANALYSIS OF WATERSHEDS FOR SOIL EROSION MANAGEMENT IN UPPER GIBE CATCHMENT

Abstract

Watershed prioritization in light of morphometric analysis has picked up significance in soil and water conservation. Morphometric investigation has been generally connected to prioritization of watershed. GIS are ended up being a successful device for prioritization of sub-basin through morphometric analysis. The upper Gibe catchment is located western parts of Ethiopia, in oromia regional state with total area of 33620 sq.km. The watershed have been divided into 61 sub-basins for taking prioritization. This study has been an endeavor to do point by point examination of linear and shape morphometric parameters like stream length, stream order, drainage density, stream frequency, bifurcation ratio, Length of overland flow, basin perimeter, form factor, compactness coefficient, elongation ratio. The morphometric analyses of sub-basins have been accomplished through the measurement of linear and shape parameters by using ArcGIS-9.3 software. The morphometric parameters which impact the soil erodibility have been considered to organize the sub-basins and relegated positions on the premise of association with erodibility so as to arrive at a compound parameter (Cp) esteem for the last positioning of each sub-basin. Based on the value of Cp the sub-basin with the lowest Cp value has been given the highest priority and then categorized the sub-basins into three classes as high, medium and low in terms of priority. The examination reveals that high priority zone comprises 11 sub-basins, medium 19 and low 31 sub-basins. The sub-basins which are falling under high priority were a great deal more defenseless to soil disintegration and ought to be given high need for land preservation measures.