1. a College of Geography and Remote Sensing Science, Xinjiang University, Urumqi 830017, China
2. b Xinjiang Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi 830017, China
3. c State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China
4. d Research Center for Ecology and Environment of Central Asia, Chinese Academy of Sciences, Urumqi 830011, China
5. e University of Chinese Academy of Sciences, Beijing 10049, China