1. Center for the Pan-third Pole Environment, Lanzhou University , Lanzhou 730000 , China
2. College of Earth and Environmental Sciences, Lanzhou University , Lanzhou 730000 , China
3. School of Geography, Nanjing Normal University , Nanjing 210023 , China
4. Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application , Nanjing 210023 , China
5. State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences , Beijing 100101 , China