1. Researcher, Office of Research and Development, Dept. of Royal Irrigation, Nonthaburi 11120, Thailand.
2. Research Assistant, Dept. of Civil, Environmental, and Architectural Engineering, Univ. of Colorado, 428 UCB, Boulder, CO 80309-0428.
3. Associate Professor, Dept. of Civil, Environmental, and Architectural Engineering, Univ. of Colorado, 428 UCB, Boulder, CO 80309-0428 (corresponding author). E-mail: keith.molenaar@colorado
4. Associate Professor, Dept. of Civil, Environmental, and Architectural Engineering; and Cooperative Institute for Research in Environmental Sciences (CIRES), Univ. of Colorado, 428 UCB, Boulder, CO 80309-0428.
5. Professor, Dept. of Civil, Environmental, and Architectural Engineering, Univ. of Colorado, 428 UCB, Boulder, CO 80309-0428.