Tracking Soil Erosion Changes in an Easily-Eroded Watershed of the Chinese Loess Plateau

Soil erosion is one of the most important environmental concerns in the hilly and gully region of the Chinese Loess Plateau. In this study, a distributed soil erosion model considering the shallow gully erosion (ephemeral gully erosion) was used to simulate and track soil erosion changes in an easily-eroded watershed from 1985 to 2010. Results indicate that: 1) The distributed soil erosion model based on the RUSLE is suitable for the hilly and gully region of the Loess Plateau and can better improve modeling capabilities for future study of sediment and pollution. 2) The overall soil erosion intensity in the southeast and central parts of the watershed is higher than that of the northwest. The spatiotemporal variations of soil erosion in the whole watershed are largely related to rainfall erosion distribution and land use layout. 3) Effects of returning farmland measures on soil erosion in the Yanhe River upstream are remarkable, and the Panlong River basin needs to further strengthen soil and water conservation measures, and the Yanhe downstream cannot also be ignored in future watershed management planning. 4) Dry land is the critical source area before and after returning farmland in the watershed. The implementation of soil and water conservation measures of dry land is a top priority for soil erosion prevention and control of the watershed. Results may provide scientific reference for erosion identification of critical source areas and land use planning in the loess hilly and gully region.