1. School of Economics, Shandong University of Finance and Economics, Jinan 250000, China
2. Key Lab. of Water Cycle & Related Land Surface Processes, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100000, China
3. Qinghai Key Laboratory of Basin Water Cycle and Ecology, Qinghai Institute of Water Resources and Hydropower, Xining 810000, China
4. China Program, The Nature Conservation, Beijing 100000, China
5. Department of Political Science, Lund University, 22100 Lund, Sweden