1. College of Urban and Environmental Sciences, Central China Normal University, Wuhan, PR China
2. Hubei Provincial Key Laboratory for Geographical Process Analysis and Simulation, Central China Normal University, Wuhan, PR China
3. School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan, PR China
4. Department of Geography, University of California Santa Barbara, Santa Barbara, CA, USA
5. Department of Land Surveying and Geo-Informatics, The Hong Kong Polytechnic University, Kowloon, Hong Kong
6. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, PR China