1. School of Civil Engineering and Geomatics, Southwest Petroleum University, Chengdu, China
2. State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing, China
3. University of Chinese Academy of Sciences, Beijing, China
4. School of Geoscience and Technology, Southwest Petroleum University, Chengdu, China
5. School of Geographical Sciences, Northeast Normal University, Changchun, China