1. School of Water Resources and Electric Power, Qinghai University, Xining 810016, China
2. State Key Laboratory of Hydroscience & Engineering, Tsinghua University, Beijing 100084, China
3. College of Water Resources & Civil Engineering, China Agricultural University, Beijing 100083, China
4. State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining 810016, China