1. Assistant Professor, Dept. of Civil and Environmental Engineering, The Hong Kong Univ. of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
2. Professor Emeritus, Dept. of Civil and Environmental Engineering, Univ. of Illinois at Urbana–Champaign, 205 N. Mathews Ave., Urbana, IL 61801.
3. Professor, Dept. of Civil and Environmental Engineering, Univ. of Illinois at Urbana–Champaign, 205 N. Mathews Ave., Urbana, IL 61801 (corresponding author).
4. Professor Emeritus, Dept. of Agricultural and Consumer Economics, Univ. of Illinois at Urbana–Champaign, 1301 W. Gregory Dr., Urbana, IL 61801.
5. Head, Center for Watershed Science, Illinois State Water Survey-Prairie Research Institute, Univ. of Illinois, 2204 Griffith Dr., Champaign, IL 61820-7495.