1. Urban Planning & Design Institute of Shenzhen; Shenzhen 518028 China; and School of Geography and Planning, Sun Yat-sen University, Guangzhou 510275, China
2. (Corresponding author) School of Geography and Planning, Sun Yat-sen University, Guangzhou 510275, China; and Guangdong Key Laboratory for Urbanization and Geo-simulation; Guangzhou 510275 China
3. Department of Geography; Kent State University; Kent OH 44242 USA