Spatiotemporal patterns of soil erosion and its relationship with environmental changes in the Binchang mining areas on the Loess Plateau of China

The mining areas of Loess Plateau accounts for over 70% of the total coal production in China, while large-scale coal mining activities have led to seriousecological degradation and intensified soil erosion. However, few studies have quantitatively investigated the spatial pattern of soil erosion rates in mining areas and its relationship with environmental change, largely constraining the implementation of land reclamation and ecological restoration in coal mining areas. In order to provide a theoretical guidance for the eco-environmental management in coal mining areas, this study, taking the Binchang mining area as a study area, derived soil erosion rates of the whole mining area between 2003 and 2019 and the subsidence area between 2014 and 2019, respectively, using the revised universal soil loss equation (RUSLE). We also investigated the spatial pattern of soil erosion rates for the whole mine area and the subsidence area and quantitatively studied the effects of precipitation, topography and vegetation cover on soil erosion rates. Results showed that: 1) During 2003-2019, soil erosion rates in the Binchang mining area showed a significant upward trend (P<0.05), with the highest and lowest rates of 85.56 and 15.54 t/(hm²·a) emerging in 2003 and 2009 respectively. Slight and light erosion was mainly distributed in flat areas such as urban areas, loess tableland and river terraces, with a consistent spatial distribution, while other levels of soil erosion intensity were mainly distributed in the coal mining area, gully areas and areas around river channels and were of high spatial hetergeneous. 2) During 2014-2019, soil erosion rates of the whole mining area and the subsidence area changed between seasons. Slight and light erosion mostly occurred in spring and autumn, while erosion rate in winter was close to 0, and highest erosion rates occurred in summer . This demonstrated that soil erosion control should be primarily undertaken in Summer in the Binchang mining area. 3) Erosion rates in the Binchang mining area were significantly positively correlated with precipitation (P<0.01), while that in the subsidence area was significantly positively correlated with precipitation, height of subsidence, and vegetation cover (P<0.01). Precipitation was the main influencing factor of soil erosion in the Binchang mining area, while the surface subsidence caused by coal mining exacerbated soil erosion. Erosion rates also varied with changes in height of subsidence. This study revealed that the spatial pattern of erosion rates in the coal mining area and its relation with environmental change, which provided a useful reference for erosion control and ecological restoration in the coal mining area of the Loess Plateau.