1. Department of Water Resources and Environment; Sun Yat-sen University; Guangzhou 510275 China
2. School of Earth Sciences and Engineering; Suzhou University; Anhui 234000 China
3. Key Laboratory of Water Cycle and Water Security in South China of Guangdong High Education Institute; Sun Yat-sen University; Guangzhou 510275 China
4. Department of Geography and Resource Management; The Chinese University of Hong Kong; China
5. Department of Biological & Agricultural Engineering; Texas A & M University; College Station TX 77843-2117 USA
6. Department of Civil and Environmental Engineering; Texas A & M University; College Station TX 77843-2117 USA
7. Nanjing Hydraulic Research Institute; Nanjing 210029 China