1. College of Geography and Remote Sensing Sciences, Xinjiang University, Urumqi 830046, China
2. College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China
3. College of Geographic Science and Tourism, Xinjiang Normal University, Urumqi 830054, China
4. GeoInformatic Unit, Geography Section, School of Humanities, Universiti Sains Malaysia, Penang 11800, Malaysia
5. Departments of Earth Sciences, The University of Memphis, Memphis, TN 38152, USA
6. Department of Social Sciences and Policy Studies, Education University of Hong Kong, Lo Ping Road, Tai Po, Hong Kong, China