1. PhD Candidate, Dept. of Civil and Environmental Engineering, Univ. of Houston, Houston, TX 77204-4003.
2. Associate Professor, Dept. of Civil and Environmental Engineering, Univ. of Houston, 4800 Calhoun, N107 Engineering Building 1, Houston, TX 77204-4003 (corresponding author). E-mail: rifai@uh.edu
3. Researcher, Dept. of Civil and Environmental Engineering, Univ. of Houston, Houston, TX 77204-4003.
4. Project Manager, Texas Commission on Environmental Quality, 12100 Park 35 Circle, Austin, TX 78753.