A STUDY ON LAND USE AND LAND COVER CHANGE AND ITS IMPACT ON SOIL EROSION BY INTEGRATING GEOSPATIAL TECHNOLOGY WITH RUSLE MODEL: THE CASE OF ADAMA DISTRICT, CENTRAL RIFT VALLEY ETHIOPIA

Abstract

The impact of Land Use and Land Cover (LULC) change on soil resources is getting global attention. The LULC change directly causes soil erosion due to different agents. In the study area soil erosion by water was considered as a main agent. The aim of this study was to assess the impacts of land use land cover change on soil erosion. Four study periods (1990, 2000, 2010, and 2020) of satellite imageries were used for the purpose of land use land cover change detection. Five factors such as rainfall erosivity (R), soil erodibility (K), topographic factor (LS), and vegetation cover (C), and conservation practice (P) were computed to estimate soil loss. The result shows that bare land, shrub land and grass land were decreased all over 30 years due to the expansion of cultivated land and built-up area. The present finding shows the increment of cultivated land and built-up land over 30 years in the study areas. This result indicated the expansion of cultivated land and built-up area at the expense of forest, shrub land, and grass land. The average annual soil loss of the study areas were estimated 35.53ton/ha/yr, 28.71ton/ha/yr, 36.09ton/ha/yr, and 35.66ton/ha/yr in 1990, 2000, 2010, and 2020 respectively. According to the result, 55.9% of the land area falls into very low to low soil erosion risk, and 16.01%, 8.94%, 11.11%, and 8.05% of the areas falls into moderate, high, very high and severe soil erosion risk classes respectively over 30 years. Cultivated land and built up area were the main cause of the soil erosion in the study areas. It can be recommended that the areas fall into moderate to severe soil erosion risk needs strong conservation practice by Adama Woreda Office of Agriculture, NGO’s and farmers to rehabilitate the areas prone to erosion to rehabilitate areas prone to erosion.