1. Professional Engineer, MWH Soft., 300 North Lake Ave., Suite 1200, Pasadena, CA 91101; formerly, PhD Candidate, Dept. of Civil Engineering, Univ. of Toronto, Toronto, ON, Canada M5S 1A4.
2. Professor, Dept. of Civil Engineering, Univ. of Toronto, Toronto, ON, Canada M5S 1A4 (corresponding author).