Assessment of soil erosion response to climate change in the Sululta catchment, Abbay Basin, Ethiopia

Abstract

This study aimed to assess the response of soil erosion to climate change in the Sululta catchment using the Revised Universal Soil Loss Equation (RUSLE) integrated with the geographic information system (GIS). The current rainfall erosivity factor (R) was computed from the current rainfall data (1989–2018). Regional climate models (RCMs) under representative concentration pathways RCP4.5 and RCP8.5 were used for future rainfall projection (2021–2080) to determine projected rainfall R factor. Rainfall data, soil map, digital elevation model and land use/land cover data were used to evaluate RUSLE factors in the ArcGIS environment. The results of this study showed that the current average annual soil loss rate was found to be 5.03 tons/ha/year. The average annual soil loss may decrease by 2.78 and 0.80% in 2021–2050 and 2051–2080, respectively, under the RCP4.5 scenario compared to the current average annual soil loss. Under the RCP8.5 scenario, the average annual soil loss may increase by 7.75 and 2.98% in 2021–2050 and 2051–2080, respectively, from the current average annual soil loss. The result reveals that the average annual soil loss decreases in both time periods under RCP4.5 and increases in both time periods under RCP8.5. HIGHLIGHTS Performing bias correction for RCM data.; Projection of future precipitation.; Determining RUSLE factors.; Determining rainfall erosivity factor under RCP4.5 and RCP8.5.; Evaluating the impact of current and future climate change on soil erosion.;

Keywords

• changing climate
• climate model
• erosivity factor
• rcp scenario
• rusle
• soil erosion