Qiang Wang¹, Haitao Wei¹, Farhad Khormali², Leibin Wang³, Hassan Azarmdel¹, Haichao Xie^1,4, Xin Wang¹, Wei Huang¹, Jianhui Chen¹ and Fahu Chen^1,5, (1)Lanzhou University, MOE Key Laboratory of West China's Environmental System, College of Earth and Environmental Sciences, Lanzhou, China, (2)Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran, (3)Guangzhou University, School of Geographical Sciences, Guangzhou, China, (4)ITP Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China, (5)Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China