[Li, Zhi-wei] Changsha Univ Sci & Technol, Sch Hydraul Engn, Changsha, Hunan, Peoples R China.^[Yu, Guo-an] Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Beijing, Peoples R China.^[Zhang, Chen-di] Tsinghua Univ, State Key Lab Hydrosci & Engn, Beijing, Peoples R China.