1. Sinohydro Engineering Bureau 4 Co., Ltd., Chengdu 610031, China
2. College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China
3. S.C.I. Energy, Future Energy Research Institute, Seidengasse 17, 8706 Zurich, Switzerland
4. State Key Laboratory of Hydroscience and Engineering, Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China