1. a College of Geographical Science, Inner Mongolia Normal University, Hohhot, Inner Mongolia 010022, China
2. b Key Laboratory of Remote Sensing and Geographic Information Systems, Inner Mongolia Normal University, Inner Mongolia, Hohhot 010022, China
3. c River and Lake Protection Center, Ordos Water Conservancy Bureau, Ordos, Inner Mongolia 017000, China
4. d Institute of Water Resources, Inner Mongolia Academy of Water Resources, Hohhot, Inner Mongolia 010010, China