1. College of Environment and Civil Engineering Chengdu University of Technology Chengdu 610059, China
2. Faculty of Geosciences and Environmental Engineering Southwest Jiaotong University Chengdu 611756, China
3. Climate and Ecosystem Sciences Division Lawrence Berkeley National Laboratory Berkeley, CA 94720, U.S.A.
4. School of Water Conservancy and Environment University of Jinan Jinan 250022, China