1. Ph.D. Candidate, Dept. of Civil and Environmental Engineering, Univ. of Alberta, Edmonton AB, Canada T6G 2W2.
2. Assistant Professor, Dept. of Irrigation and Reclamation Engineering, Univ. College of Agriculture and Natural Resources, Univ. of Tehran, P. O. Box 4111, Karaj, 31587-77871, Iran.
3. Emeritus Professor, Dept. of Civil and Environmental Engineering, Univ. of Alberta, Edmonton AB, Canada T6G 2W2 (corresponding author).