1. Professor, Dept. of Civil and Environmental Engineering, Univ. of Maryland, College Park, MD 20742 (corresponding author).
2. Professor, Dept. of Civil and Environmental Engineering, Villanova Univ., 800 Lancaster Ave., Villanova, PA 19085.
3. Associate Professor and Extension Specialist, Dept. of Biological and Agricultural Engineering, North Carolina State Univ., Campus Box 7625, Raleigh, NC 27695-7625.
4. Graduate Research Assistant, Dept. of Biological and Agricultural Engineering, North Carolina State Univ., Campus Box 7625, Raleigh, North Carolina 27695-7625.
5. Graduate Student, Dept. of Civil and Environmental Engineering, Villanova Univ., 800 Lancaster Ave., Villanova, PA 19085.
6. Graduate Student, Dept. of Civil and Environmental Engineering, Univ. of Maryland, College Park, MD 20742.