1. School of Geography and Tourism; Shaanxi Normal University; Xi'an China
2. State Key Laboratory of Cryospheric Sciences; Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences; Lanzhou China
3. College of Resources and Environment; University of the Chinese Academy of Sciences; Beijing China
4. College of Urban and Environmental Sciences; Northwest University; Xi'an China
5. Department of Earth Sciences; Indiana University-Purdue University Indianapolis; Indianapolis Indiana USA
6. College of Forestry; Inner Mongolia Agricultural University; Hohhot China
7. The Key Laboratory of Mountain Environment Evolution and Regulation; Institute of Mountain Hazards and Environment, Chinese Academy of Sciences; Chengdu China