Projection of Rainfall Erosivity under Climate Change in Northeast China Using a High-Resolution Regional Model

Soil erosion is an important factor affecting the ecological environment and agricultural production globally. The three northeastern provinces of China have an area of 793300 km², accounting for 9.3％ of its total land area. These provinces are among the four black soil regions in the world and an important commodity grain base. Soil erosion in Northeast China and its future risks are still unclear given climate change. The main meteorological factor affecting soil erosivity is heavy precipitation. Based on this relationship, the observational precipitation data of CN05.1 and APHRODITE were used to reveal the characteristics of rainfall erosivity in Northeast China. In terms of the mean climate, rainfall erosivity is the strongest in the southeast of Northeast China. The rainfall erosivity shows an evident annual cycle. Rainfall erosivity in summer (June–July–August) contributes to over 80% of the annual total. Based on the observational analysis, the RegCM4 dynamic downscaling model is evaluated and bias-corrected. The future changes in the rainfall erosivity in Northeast China under different shared socioeconomic pathways (SSP1-2.6 and SSP5-8.5) are subsequently examined. With future global warming, the mean rainfall erosivity in Northeast China will increase by 9.90% and 26.70%, respectively, by the end of the 21st century. Under the high-emission scenario (SSP5-8.5), a higher risk of rainfall erosion is expected, with a rainfall erosivity 2.7 times greater than that under the SSP1-2.6 scenario, and 77.69% area is projected to experience more severe rainfall erosivity. Therefore, it is of great significance to deploy effective emission reduction measures and follow sustainable development to reduce the soil erosion risk of black land in Northeast China and ensure food security.