1. Center of Integrated Geographic Information Analysis, School of Geography and Planning; Sun Yat-sen University; Guangzhou China
2. Key Laboratory of Water Cycle and Water Security in Southern China of Guangdong High Education Institute; Sun Yat-sen University; Guangzhou China
3. School of Geographical Science; Center of GeoInformatics for Public Security, Guangzhou University; Guangzhou China
4. Department of Geography; University of Cincinnati; Cincinnati Ohio