Investigating soil erosion processes from source-to-sink to prioritise erosion hotspots in the Ethiopian highlands
Haftu Yemane Hadush, Berhane Grum, Jantiene Baartman, Kebede Wolka, Niguse Abebe Hagos, Ton Hoitink & Martine van der Ploeg
https://doi.org/10.1016/j.envc.2025.101173
Existing erosion prediction models are often compared solely to sediment outflow at catchment outlets without explicitly assessing the dominant erosion processes in the catchment. This study combined the unit stream power erosion deposition (USPED) model and gully erosion indices with a spatial-validation approach to assess sediment redistribution patterns of a sub-humid catchment in the Ethiopian highlands. Sediment measurements from a plot and a sub-watershed, along with delta development at a reservoir inlet, were used for spatial model evaluations. The main findings indicated that the dominant soil erosion processes vary by spatial scale, emphasising the need for scale-aware modelling, with distinct erosion processes involved. Besides, just 18 % of the catchment area contributed approximately 69 % of the total soil erosion. In conclusion, the USPED model, combined with gully erosion indices, effectively captures the dominant erosion processes at various scales and identifies hotspots for targeted conservation amid land use and climate changes.
Environmental Fluid Mechanics 