1. Remote Sensing Information and Digital Earth Center, College of Computer Science and Technology, Qingdao University, Qingdao 266071, China
2. Key Laboratory of Digital Earth Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100094, China
3. Laboratory of Eremology and Combating Desertification, Institut des Regions Arides (IRA), Medenine 4119, Tunisia
4. Arba Minch Water Technology Institute, Water Resources Research Center, Arba Minch University, Arba Minch P.O. Box 21, Ethiopia
5. National Remote Sensing Center, Information and Research Institute of Meteorology, Hydrology and Environment (IRIMHE), Ulaanbaatar 15160, Mongolia