Background Guishui River Basin is an important water conservation area and significant ecological barrier in Beijing, and it is also one of the host sites of the 2022 Winter Olympics. Therefore, it is of great practical significance to explore the influence of vegetation cover on soil erosion in the Guishui River Basin for effective soil erosion control and ecological environment improvement to ensure the smooth preparation of the Winter Olympics.

Methods In this study, the soil erosion intensity and soil erosion control index in the Guishui River Basin from 2000 to 2018 were estimated based on RUSLE model. The influence law of vegetation cover change on soil erosion control efficiency in the Guishui River Basin was revealed.

Results 1) The soil erosion intensity in Guishui River Basin showed a downward trend from 2000 to 2008, and increased significantly in 2013, then decreased slightly in 2018, which was not only related to the ecological restoration policies in the basin, but also affected by the inter-annual difference of rainfall intensity. It showed that the spatial variation of vegetation cover in the Guishui River Basin was obvious. The area with high coverage was mainly the natural forestland in the northwest and the eastern edge of the basin, while the coverage in the middle part of the basin was low. What is more, the vegetation coverage improved significantly from 2000 to 2018. 2) Analysis on the efficiency of soil erosion control showed that it was high in Guishui River Basin, and the average value of soil erosion control index from 2000 to 2018 was over than 0.92. It firstly showed a rising trend from 2000 to 2013, reaching the maximum in 2013, but there was a downward trend in 2018. Among them, the control efficiency was high in the northwest mountain area and the central plain area, and low in other areas. 3) The vegetation coverage had a significant impact on the efficiency of soil erosion control, which had negative relationship in few areas with cropland converted into forestland and grassland, but positive in most other areas. When the coverage of forestland was 30%-70%, that of grassland 20%-50%, and that of cropland and orchard 25%-50%, the quadratic function can better represent the relationship between the soil erosion control index and vegetation coverage. In addition, the control efficiency increased with the increase of vegetation coverage.

Conclusions These results can provide an important reference for soil and water conservation, ecological environment construction and vegetation restoration in Guishui River Basin. Vegetation coverage improvement is an effective way to control soil erosion. In the process of land use type conversion, attention should be paid for the environmental protection so as to avoid intense soil erosion in the short term.