1. Engineering Dept., George Fox Univ., 414 N. Meridian St., Newberg, OR 97132 (corresponding author).
2. Environmental Research Group, Civil Engineering Dept. and Institute for the Study of Earth, Oceans and Space, Univ. of New Hampshire, 248 Gregg Hall, Durham, NH 03824.
3. Dept. of Civil and Environmental Engineering, Michigan Technological Univ., 1400 Townsend Dr., Houghton, MI 49931.