1. Water Resource Engineer, South Carolina Dept. of Natural Resources, Columbia, SC 29201. E-mail: aregaf@dnr.gov; formerly NRC Research Associate, U.S. Environmental Protection Agency, Athens, GA 30605.
2. Professor, Dept. of Civil Engineering, Univ. of Hong Kong, Pokfulam, Hong Kong. E-mail: hreclhw@hkucc.hku.hk
3. Professor, College of Water Conservancy and Hydropower Engineering, Hohai Univ., Nanjing 210098, China.