A Geographic Information System Based Soil Loss and Sediment Estimation in Zingin Watershed for Conservation Planning, Highlands of Ethiopia

Abstract

Zingin watershed is one of the most erosion-prone watersheds in the highlands of Ethiopia which received little attention. This study was, therefore, carried out to spatially predict the soil loss rate of the watershed with a Geographic Information System (GIS) and Remote Sensing (RS). Revised Universal Soil Loss Equation (RUSLE) adapted to Ethiopian conditions was used to estimate potential soil losses by utilizing information on rainfall erosivity (R) using interpolation of rainfall data, soil erodibility (K) using soil map, vegetation cover (C) using satellite images, topography (LS) using Digital Elevation Model (DEM) and conservation practices (P ) using satellite images. Based on the analysis, the total annual soil loss potential of the study watershed Based on the analysis, the mean and total annual soil loss potential of the study watershed was 9.10 ton tons/yr and 57750.15 t/yr, respectively. About 78.31% (4969.63 ha) of the watershed was categorized none to slight class which under SLT values ranging from 5 to 11 tons ha-1yr-1. The remaining 21.69% (1376.48 ha) of land was classified under moderate to high class about several times the maximum tolerable soil loss (11 tons ha-1 y-1). The study demonstrates that the RUSLE together with GIS provide a good estimate soil loss rate over areas.