Modelling and mapping soil erosion potential in China
TENG Hong-fen1, 2, HU Jie1, ZHOU Yue1, ZHOU Lian-qing1, SHI Zhou1
1 College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, P.R.China 2 State Key Laboratory of Soil and Sustainable Agriculture, Chinese Academy of Sciences, Nanjing 210008, P.R.China
Soil erosion is an important environmental threat in China. However, quantitative estimates of soil erosion in China have rarely been reported in the literature. In this study, soil loss potential in China was estimated by integrating satellite images, field samples, and ground observations based on the Revised Universal Soil Loss Equation (RUSLE). The rainfall erosivity factor was estimated from merged rainfall data using Collocated CoKriging (ColCOK) and downscaled by geographically weighted regression (GWR). The Random Forest (RF) regression approach was used as a tool for understanding and predicting the relationship between the soil erodibility factor and a set of environment factors. Our results show that the average erosion rate in China is 1.44 t ha–1 yr–1. More than 60% of the territory in China is influenced by soil erosion limitedly, with an average potential erosion rate less than 0.1 t ha–1 yr–1. Other unused land and other forested woodlands showed the highest erosion risk. Our estimates are comparable to those of runoff plot studies. Our results provide a useful tool for soil loss assessments and ecological environment protections.
Fund: This work was supported by the National Natural Science Foundation of China (41461063 and 41571339), the China Postdoctoral Science Foundation (2018M630682), the Research Fund of State Key Laboratory of Soil and Sustainable Agriculture, Nanjing Institute of Soil Science, the Chinese Academy of Sciences (Y412201430).