1. Associate Professor, Dept. of Civil Engineering, Univ. of New Mexico, MSC 01 1070, Albuquerque, NM 87131.
2. Graduate Research Assistant, Dept. of Civil Engineering, Univ. of New Mexico, MSC 01 1070, Albuquerque, NM 87131 (corresponding author).
3. Engineer Specialist, A/O-NL-A, New Mexico Interstate Stream Commission, P.O. Box 25102, Santa Fe, NM 87504; formerly, Graduate Research Assistant, Dept. of Civil Engineering, Univ. of New Mexico, MSC 01 1070, Albuquerque, NM 87131.