1. Hefei University of Technology,School of Resources and Environmental Engineering,Hefei,China,230009
2. Beijing Normal University,State Key Laboratory of Remote Sensing Science, Faculty of Geographical Science,Beijing,China,100875
3. Northwest A&F University,College of Soil and Water Conservation Science and Engineering,Xian,China,712100
4. Hefei University of Technology,School of Civil Engineering,Hefei,China,230009
5. University of Zurich,Department of Geography,Zurich,Switzerland,8057