1. Ph.D. Student, College of Hydrology and Water Resources, Hohai Univ., Nanjing 210098, China; Senior Engineer, Huaihe River Basin Meteorological Center, Bengbu 233040, China (corresponding author).
2. Ph.D. Student, Nanjing Univ. of Information Science and Technology, Nanjing 210044, China.
3. Professor, College of Hydrology and Water Resources, Hohai Univ., Nanjing 210098, China.