1. Department of Civil and Environmental Engineering, University of Nevada, Reno, Nevada 89557-0258, United States
2. School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0355, United States
3. Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
4. Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, P.R. China
5. Department of Civil, Environmental, and Geo-Engineering, University of Minnesota, Minneapolis, Minnesota 55455-0116, United States