1. Academy of Ecological Civilization Development for JING-JIN-JI Megalopolis, Tianjin Normal University, Tianjin 300387, China
2. School of Earth Sciences and Engineering, College of Geography and Remote Sensing, Hohai University, Nanjing 210098, China
3. College of Resources, Environment and Tourism, Capital Normal University, Beijing 100048, China
4. College of Geomatics, Xi’an University of Science and Technology, Xi’an 710054, China