1. Senior Engineer, American Electric Power Inc., Columbus, OH.
2. Professor, Dept. of Civil and Environmental Engineering, and IIHR-Hydroscience & Engineering, The Univ. of Iowa, Iowa City, IA 52242 (corresponding author).
3. Research Engineer, Dept. of Civil and Environmental Engineering, and IIHR-Hydroscience & Engineering, The Univ. of Iowa, Iowa City, IA 52242.