Trends in soil loss influenced by climate, land use, and land cover change in the Upper Awash Subbasin, Ethiopia

Soil erosion is a global environmental challenge that affects ecological sustainability and land productivity, highlighting the need for evidence-based land management strategies. The problem is particularly severe in the Ethiopian highlands, where rapid land use/land cover (LULC) change and climate variability accelerate soil erosion. This study assessed historical and future soil loss trends under the combined influence of climate and LULC dynamics in the Upper Awash Subbasin. The LULC maps were classified using Landsat imagery, and future LULC was simulated using a Cellular Automata–Artificial Neural Network (CA-ANN) model. The support practice (P) and cover management (C) factors were derived from the classified LULC classes. The rainfall-runoff erosivity (R) factor was estimated using observed rainfall records and projected CMIP6 data under shared socioeconomic pathways (SSPs) scenarios. The Revised Universal Soil Loss Equation (RUSLE), integrated with geographic information system (GIS), was applied to estimate soil loss for the historical and projected periods. The results indicate a declining rainfall trend during the historical period, followed by substantial increases in projections at most stations and scenarios. Cultivated land and settlement areas expanded considerably, while natural vegetation declined, except for a temporary increase in forest cover between 2000 and 2020. Mean annual soil loss was estimated at 12.34, 9.65, and 14.8 t ha −1 yr −1 for 1980, 2000, and 2020, respectively, and is projected to increase to 19.78–33.11 t ha −1 yr −1 by 2060 under different SSP climate change scenarios and a CA-ANN-based LULC trajectory. The combined effects of the projected increase in rainfall and LULC dynamics will likely intensify soil erosion, which is expected to affect ecosystem sustainability, agricultural productivity, and consequently the livelihoods of local communities. The findings highlight the urgent need for collaborative planning and implementation of ecologically sound, sustainable land management strategies to mitigate soil erosion.