IMPACT OF LAND USE/LAND COVER CHANGE ON SOIL EROSION AND SEDIMENT YIELD IN BORKENA SUB-BASIN, AWASH RIVER BASIN, ETHIOPIA

Abstract

There is a growing global focus on the impacts of land-use land-cover (LULC) change on soil resources, particularly due to its significant impact. Soil erosion, a crucial environmental issue of great magnitude, is particularly severe in developing nations. This study aimed to assess the impact of land use/land cover change on soil loss and sediment yield using the Revised Universal Soil Loss Equation (RUSLE) within a Geographic Information System (GIS) environment in Borkena watershed, Awash river basin, Ethiopia. The study used Land Use Land Cover (LULC) maps of 2010 and 2020 to evaluat the impact of land use land cover change on soil loss and sediment yield. Various factors, such as rainfall erosivity, soil erodibility, slope length and steepness, cover management, and conservation practices were considered to calculate soil erosion potential between 2010 and 2020. The integration of the RUSLE and GIS was used to analyze the impact of LULC change on soil erosion and sedimentation. The mean annual soil loss from the watershed was estimated to be 8.13 t/ha/yr in 2010 and 10.34 t/ha/yr in 2020 . Cultivated lands produced the highest rates of soil loss and sediment yield, followed by bare land and grass land areas, when compared to other land uses/covers. The mean annual sediment yield was estimated to be 2.61 t/ha/yr in 2010 and 2.87 t/ha/yr in 2020. The sediment delivery ratio (SDR) of the watershed ranged between 0 and 0.549. The implications of this study's findings emphasize the need for immediate action to address soil erosion and sedimentation issues in the Borkena watershed. By implementing targeted soil and water conservation measures, integrating land use planning with conservation efforts, rehabilitating degraded lands, and formulating supportive policies, it is possible to mitigate the adverse impacts of land use/land cover change and promote sustainable land and water resource management in the watershed.