1. College of Environment & Safety Engineering, Fuzhou University, Fuzhou 350116, China
2. Fujian Provincial Engineering Research Centre for Monitoring and Assessing Terrestrial Disasters, Fujian Normal University, Fuzhou 350007, China
3. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling District, Xianyang 712100, China
4. Institute of Soil and Water Conservation, Chinese Academy of Sciences & Ministry of Water Resources, 26 Xinong Road, Yangling District, Xianyang 712100, China