1. Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, School of Geographical Sciences, Fujian Normal University Cangsan Campus, Fuzhou 350007, China
2. School of Computing, University of the Fraser Valley, Abbotsford, BC V2S 7M7, Canada
3. Department of Geography and Planning, University of Toronto, Toronto, ON M5S 3G3, Canada