Assessing the impact of land use/land cover change on soil erosion risk in Gulu district

Abstract

The impact of land use land cover change on soil resources remains a global issue, with soil erosion being one of the critical environmental challenges worldwide. This study aimed to determine the effect land use and cover change had on soil erosion risk in Gulu district from 1990 to 2022. The Revised Universal Soil Loss Equation model (RUSLE) was integrated with a Geographic Information System (GIS) to estimate the impacts of land use land cover conversion on the mean annual soil loss in Gulu district. In this study, land use land cover change of Gulu district was assessed from 1990 to 2022 by using Landsat Thematic Mapper (TM), Enhanced Thematic Mapper Plus (ETM+) and Operational Land Imager sensor (OLI) images and classified using supervised maximum likelihood classification algorithms. Findings revealed significant land use land cover changes in Gulu district, with built-up areas expanding from 11.63% in 1990 to 60.41% in 2022 and vegetation cover decreasing from 66.45% in 1990 to 12.33% in 2022. Mildly eroded areas increased from 83.36% to 94.31%, while more severe erosion areas declined suggesting improvements in land management practices. The highest soil erosion rates of 0.84 tons/ha and 0.47 tons/ha were realized in the conversion of land cover into bare land and built up, respectively. Results further indicated that the conversion of forests to bare lands was the primary contributor to increased soil erosion. Therefore, rapid urbanization and vegetation loss in Gulu district have significantly increased the risk of soil erosion over the past three decades.