Analysis Of The Glacier Area Change And Climate Response In The Indus Basin Based On Satellite Remote Sensing

Glaciers are considered to be one of the key indicators of global change,and climate change can also cause changes in glacier accumulation and ablation,resulting in increase or decrease in glacier area.The long-term trend of glaciers in the Indus basin and the relationship between climate and glacier change are not only important scientific problems but also have a significant impact on the lack of water resources in the middle and lower reaches.This paper is supported by the Key Project of the International Cooperation Bureau of the Chinese Academy of Sciences,the 13thFive Year Plan Project of Chinese academy of sciences and and the Key Laboratory of Tibetan Environment Changes and Land Surface Processes.In this paper,through remote sensing and GIS techniques,Landsat TM,ETM+and OLI images were used as data sources to extract the glacier boundary in the upper reaches of the Indus River Basin from 1991 to 2014.First of all,by comparing several commonly used glacier extraction methods,the band ratio method was used to extract the glacier contours of the study area,and the five glacier data of 40 typical glaciers were obtained by artificial revision.This paper analyzes the variation characteristics of glacier area in Hingdu Kushi,Karakorum and western Himalayas in the Indus basin.In this paper,the spatial and temporal changes of glaciers in the Karakoram region are analyzed,and the variation rules of glaciers with different elevation and size are revealed.At the same time,combined with the meteorological data of Delaware University from 1991 to 2014,the change of glacier area and climate response were compared and analyzed in the Hingdu Kushi,Karakorum and western Himalayas of the Indus basin.The main conclusions are as follows:(1)Based on the analysis of glacier extraction from 1991 to 2014,it is found that the glaciers in the western part of Hindu Kushi and the western Himalayas show a tendency to retreat,and glaciers in the Karakorum area have an expansion phenomenon.The expansion phenomenon mainly occurs in the Shigar River Basin and Shijk River River Basin.(2)By analyzing the variation of glacier area with different elevation range and size in the Karakoram region,it is found that the glacier changes of different elevation range and scale have regularity.The glacier expansion in the study area occurred in glaciers with an elevation range of 5400?5600 m and an area of less than 10 km2.The glaciers at altitudes below 5000 m are relatively small and have the highest sensitivity to climate change.When the glaciers are at high altitudes and have a certain scale,the sensitivity to climate is reduced and the rate of glacier changes is slow.(3)By analyzing the characteristics of temperature and precipitation in the study area,it is found that the temperature and precipitation in the study area show a trend of increasing volatility,but only the annual average temperature in the Karakoram region is below 0?.The amount is higher than the summer.Precipitation in the western part of the Himalayas is mainly concentrated in the summer.The precipitation in the Karakoram region has two peaks in winter and summer,and the precipitation in winter is higher than that in summer.(4)The glacier expansion in the Karakoram region may be related to the following two reasons.First,the area affected by the westerly,winter precipitation is higher than the summer precipitation;Second,the annual average temperature of the Karakorum is below the freezing point.These make although the precipitation is increasing in the entire study area,only the precipitation in the Karakoram region can accumulate in the form of winter snowfall.