Abstract:

Glaciers and snow cover are indicators of global warming and important water resources for human survival and development in arid regions. Since 1900s,the glacier and snow area has generally been shrinking as global warming intensifies, which seriously affects people’s life, social and economic activities in the related areas. Particularly, in the surrounding areas of Mount Bogda which located in the arid area of northwest China, this kind of effects is much more significant. By strengthening the monitoring the change of glacier and snow cover, we can not only understand the characteristics and trends of glacier and snow change, but also reveal the response of glacier and snow to climate change, and thus to possibly predict future changes of glacier and snow. We chose Mount Bogda at Fukang County, Xinjiang, China as the research area and obtained remote sensing images of Landsat 5 and Landsat 8,DEM data and surrounding temperature and precipitation data from 1990 to 2016.Firstly，we employed the satellite images of Landsat 5 and Landsat 8 to calculate value of Normalized Difference Snow Index (NDSI),Normalized Difference Snow-Glacier Index (NDSII), Normalized Difference Principle Component Snow Index (NDPCSI) and Tasseled Cap Wetness transformation (WET) and to analyze the respective ability to detect glacier and snow. Secondly, we used WET with high accuracy to obtain glacier and snow cover data in 1990, 2000, 2010 and 2016 respectively and analyzed the changes of glacier and snow cover. Finally, combining with the temperature data and the terrain data of the study area, we explored the relationship between the change of snow and glacier area of Mount Bogda and the terrain and climate in this area. The results show as follows: (1) The WET index has a higher overall accuracy than the NDSI index, which can replace NDSI and NDSII to detect and monitor the glacier and snow area changes in Mount Bogda. (2) The area of snow and glacier continued to shrink in Mount Bogda. From 1990 to 2016, the snow and glacier area was reduced by 20.07%, and the annual reduction rate continues to increase. (3) The influence of temperature and slope on the change of snow and glacier area is strong, while the influence of mountain shadow and altitude is weak. And the rising temperatures is the main factor of the decreased area of snow and glacier. The research results could provide theoretical support and decision reference for accurate extraction of glacier and snow cover information in Mount Bogda area and for the sustainable economy development in the surrounding areas.

Key words: Times New Roman", ,serif, Landsat')">">Landsat, index, variations of glacier and snow, Mount Bogda