1. School of Computer and Communication, Lanzhou University of Technology, Lanzhou, China
2. School of Life Sciences, Lanzhou University, Lanzhou, China
3. Key Laboratory of Remote Sensing of Gansu Province, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
4. National Tibetan Plateau Data Center, State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China