[Analysis and Prediction of Soil Erosion Under Different Land Use Change Scenarios in Kuye River Basin Based on PLUS-CSLE Model].

Abstract

The distribution of land use types is a comprehensive reflection of natural conditions and human activities, which affects the process of runoff and sediment transport by changing the surface morphology, and then affects the process of soil erosion. Based on the land use data in the Kuye River Basin from 2010 to 2020, this study uses the PLUS model to predict the land use distribution in 2025 under three scenarios and evaluates the soil erosion intensity from 2010 to 2025 on CSLE model, so as to explore the impact of land use change on soil erosion. The results showed that： ① From 2010 to 2020, the land use distribution in the Kuye River Basin was dominated by grassland and farmland. The area of farmland and grassland decreased, while the construction land and unused land increased. The expansion of farmland and grassland was mainly affected by elevation, rainfall, and population, and the expansion of construction land was mainly because of human activities. ② The soil erosion intensities in 2010, 2015, and 2020 were 25.91, 22.82, and 27.58 t·（hm²·a）^-1, respectively, showing a trend of first weakening and then rebounding. ③ The soil erosion intensities under the simulated natural development, ecological protection, and economic growth scenarios in 2025 were 25.62, 24.60, and 27.41 t·（hm²·a）^-1. The ecological protection scenario was better for controlling the soil erosion. ④ The areas with the most soil erosion in the basin were mainly the grassland and farmland in the loess gully in the central and southern parts, as well as the degraded land around some industrial/mining concentration parts. To effectively reduce the soil erosion, increasing forest and grassland while reducing the farmland and industrial/mining zones is suggested. Notably, focus should be on bolstering the upkeep and preserving terraced farmlands.