1. Assistant Professor of Hydrology, Dept. of Earth and Environmental Science, New Mexico Inst. of Mining and Technology, 801 Leroy Place, MSEC 244, Socorro, NM 87801.
2. Graduate Research Assistant, Dept. of Civil and Environmental Engineering, Massachusetts Inst. of Technology, 77 Massachusetts Ave., Room 48-212, Cambridge, MA 02139.
3. Professor, Dept. of Civil and Environmental Engineering, Massachusetts Inst. of Technology, 77 Massachusetts Ave., Room 48-211, Cambridge, MA 02139.
4. Professor, Dept. of Civil and Environmental Engineering, Massachusetts Inst. of Technology, 77 Massachusetts Ave., Room 48-331, Cambridge, MA 02139.