1. College of Geographical Science, Inner Mongolia Normal University, Hohhot 010022, China
2. Inner Mongolia Key Laboratory of Remote Sensing and Geographic Information Systems, Inner Mongolia Normal University, Hohhot 010022, China
3. Information Center, Inner Mongolia Normal University, Hohhot 010022, China
4. Department of Geography, School of Arts and Sciences, National University of Mongolia, Ulaanbaatar 14201, Mongolia
5. College of Computer Science and Technology, Inner Mongolian Normal University, Hohhot 010022, China