Tao Che¹, Liyun Dai¹, Xiaodong Huang², Xiaohua Hao¹ and Xin Li³, (1)Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China, (2)Nanjing University of Information Science & Technology, Nanjing, China, (3)Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China