1. Guangdong Open Laboratory of Geospatial Information Technology and Application, Guangzhou Institute of Geography, Guangdong Academy of Sciences, Guangzhou 510070, China
2. School of Geographical Sciences, South China Normal University, Guangzhou 510631, China
3. Department of Geography and Geology, Eastern Michigan University, Ypsilanti, MI 48197, USA
4. Guangdong Provincial Key Laboratory of Silviculture, Protection and Utilization, Guangdong Academy of Forestry, Guangzhou 510520, China