Xianwei Wang, Sun Yat-Sen University, Guangzhou, China, Hongjie Xie, University of Texas at San Antonio, San Antonio, TX, United States, Stephen F Ackley, UTSA, San Antonio, TX, United States, Huan Li, Peking University, Institute of Remote Sensing and GIS, School of Earth and Space Sciences, Beijing, China and Weixu Jiang Sr., Sun Yat-sen University, School of Geography and Planning, Guangzhou, China