1. Key Laboratory of Land Resources Survey and Planning of Qinghai Province, School of Politics and Public Administration, Qinghai Minzu University, Xining 810007, China
2. State Key Laboratory of Soil Erosion and Dry Land Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, China
3. Key Laboratory of the Soil and Water Conservation on the Loess Plateau of Ministry of Water Resources, Yellow River Institute of Hydraulic Research, Yellow River Conservancy Commission of Ministry of Water Resources, Zhengzhou 450003, China
4. Medical Education, Lanzhou University, Lanzhou 730000, China
5. School of Automation, Northwestern Polytechnical University, Xi’an 710072, China