Morphometric analysis and prioritization of watersheds for soil erosion management in Upper Gibe catchment

Abstract

As morphometric investigation is connected to prioritization of watershed, morphometric analysis has got a significance role in light of soil and water conservation. In this study, an endeavour for the examination of point by point morphometric analyses of sub-basins was accomplished through the measurement of linear and shape parameters by using ArcGIS-9.3 software. Specifically, 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 has been considered. The SRTM DEM (30 x 30 m) is processed for the delineation resulting in 61 sub-basins. The morphometric parameters which affect the soil erodibility are considered to organize the sub-basins and relegate positions on the premise of their association with erodibility to get compound parameter (Cp) esteem. Based on the value of Cp the sub-basin with the lowest Cp value was given the highest priority and then categorized the sub-basins into three classes as high, medium and low in terms of priority. Accordingly, 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 defenceless to soil disintegration and ought to be given high need for land preservation measures.