Effects of land-use management on soil erosion: A case study in a typical watershed of the hilly and gully region on the Loess Plateau of China

Abstract

The effect of land use on erosion over space and time is relevant. In this study, two types of land-use management practices, the gully land consolidation (GLC) project and the land consolidation (LC) project, were applied on the Loess Plateau. Based on the soil erosion that occurred from 2010 to 2019, the spatial distribution, spatiotemporal evolution and susceptibility map of soil erosion were analyzed by geospatial analysis, statistical methods and frequency ratio (FR) models. The results showed that the implementation of the GLC project can have two effects on soil erosion. Firstly, a large amount of slope erosion was caused by slope excavation in the GLC watershed; secondly, the amount and scale of gully erosion were effectively controlled by hydraulic engineering. In addition, the unreasonable hydraulic engineering of the LC project can cause large areas of soil erosion. The influencing factors of gully erosion can be ranked as follows: reservoir > elevation > dam land > flow length > geology > LS. Three aspects of engineering optimization measures for the GLC project were proposed: 1. Slope excavation should be reduced, and diverse slope protections should be implemented in this project, especially for the bottom of the slope, which should adopt different measures than the top of the slope. 2. For trenches within 1.2 km of the gully head, more attention should focus on soil and water conservation measures than on land leveling. 3. Hydraulic engineering and irrigation and drainage engineering should effectively cooperate with leveling projects and adjust the applied measures to the local conditions and the natural shape of the original rivers. As a new land-use management approach, our results highlight that little is known about the effect of the GLC project on soil erosion, and our results can provide specific guidance for the next step of project implementation.