1. Chinese Research Academy of Environmental Sciences, Beijing 100012, China
2. State Key Laboratory of Resources and Environmental Information Systems, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
3. College of Resources and Environment, University of Academy of Sciences, Beijing 100049, China
4. Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing 210023, China
5. Department of Urban Informatics, School of Architecture and Urban Planning, Shenzhen University, Shenzhen 518060, China