1. Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
2. Berkeley Water Center, University of California Berkeley, 410 O’Brien Hall, Berkeley, California 94720-1718, United States
3. Energy and Resources Group, College of Natural Resources, University of California Berkeley, 310 Barrows Hall, Berkeley, California 94720-3050, United States
4. Sino-French Institute for Earth System Science, Peking University, Beijing 100871, China