Impact evaluation of sustainable land management interventions on soil loss reduction and sediment retention in Ethiopia

Abstract

Agricultural sector is the backbone of the national economy of Ethiopia. The sector provides raw materials for industries and offers employment opportunities to a significant portion of population. The highland part is known for farming practices; however, it faces severe soil erosion. As a response, the government of Ethiopia implemented sustainable land management (SLM) practices for long time. The aim of this study was to assess the impacts of SLM works for soil erosion reduction from 2003 to 2022, because previously available studies focus on the watershed level. The data was collected from national meteorological stations, field data, and Landsat images (Landsat 7 and 8 imageries). Land use and land cover (LULC) changes were produced to compute soil erosion and sedimentation. The soil loss was estimated using the integrated valuation of ecosystem services and trade-offs (InVEST) sediment delivery model. The findings showed that SLM intervention contributed to increased vegetation cover. The mean soil loss declined from 52.1 tons ha −1 (95% confidence interval (CI) of 30.7–73.51 ha −1 yr −1 ), in 2003 to 16.1 tons ha −1 (95% CI of 9.67–22.44 ha −1 yr −1 ) in 2022. The sediment export was also reduced from 12.3 to 3.4 tons ha −1 (95% CI of 9.67–22.44 ha −1 yr −1 ) from 2003 to 2022. The soil loss was reduced from 468.9 to 144.5 tons yr −1 from a land size of 483,810 hectares. In conclusion, the SLM interventions help to reduce soil loss. As a result, it has a valuable effect on increasing soil-related ecosystem services and soil formation.