Soil erosion dynamics in response to watershed management practices in Urago micro-watershed, central highland of Ethiopia

Abstract

Water-induced soil erosion poses a significant threat to agricultural productivity and soil quality in the Ethiopian highlands, including the Urago micro-watershed. Despite the implementation of watershed management practices (WMPs), their effectiveness at the watershed scale has not been thoroughly studied. This research utilized the Revised Universal Soil Loss Equation (RUSLE) integrated with Geographic Information Systems (GIS) to assess soil erosion dynamics in 2005 and 2021, following the government-led WMPs initiated in 2010. Erosion rates were analysed using data on rainfall, soil properties, land use, topography, and conservation practices. The findings revealed that the annual soil erosion rate ranged from 0 to 486 t ha⁻1 year⁻1 in 2005 and increased to 0 to 667 t ha⁻1 year⁻1 in 2021, reflecting a 37% rise. Notably, soil erosion rates decreased by 13%, 0.64%, and 16% in the slight, moderate, and severe erosion risk classes, respectively, while the high erosion risk class experienced a 29% increase between 2005 and 2021. Additionally, significant reductions in soil erosion were observed in moderately steep (10%) and steep slope categories (30%), as well as in areas with moderate cover (29%). These improvements are likely due to the targeted implementation of WMPs in the upper sections of the watershed. In conclusion, the strategic application of WMPs in specific areas of the Urago micro-watershed has effectively reduced soil erosion rates, particularly in regions previously identified as high-risk. These findings highlight the importance of localized and targeted watershed management strategies in mitigating soil erosion and promoting sustainable land use.