1. Faculty of Geomatics, Lanzhou Jiaotong University, Lanzhou, People’s Republic of China
2. Department of Geography, University of California, Santa Barbara, CA, USA
3. National-Local Joint Engineering Research Center of Technologies and Applications for National Geographic State Monitoring, Lanzhou, People’s Republic of China
4. Lanzhou Information Center, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, People’s Republic of China
5. Key Laboratory of Digital Earth Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, People’s Republic of China
6. Gansu Provincial Engineering Laboratory for National Geographic State Monitoring, Lanzhou, People’s Republic of China