1. Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environment Sciences, Lanzhou University, Lanzhou 730000, China.
2. Department of Geology and Geophysics, University of Minnesota, Minneapolis, MN 55455, USA.
3. College of Geography Science, Nanjing Normal University, Nanjing 210097, China.
4. Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
5. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China.