Monitoring Glacier Change On West Kunlun Shan Based On Multi-source Remote Sensing Data

West Kunlun Shan is one of the major area of modern glaciers in China,there being a large number of mountain glaciers.It is an important part of the Tibetan Plateau.Climate change and aggravated human activities will increase the uncertainty of water resources utilization and climate response in this area in the future.Glacier changes in size,length,velocity and mass balance are direct or delayed feedback of climate change.Monitoring these changes with remote sensing data,exploring their trend and driving mechanism can provide scientific basis and decision support for the sustainable development of of resources in this region.Sentinel-1 Level1 SLC(Single Look Complex)and Landsat8 OLI LIT multi-spectral data were used to identify clear glacier and debris-covered glacier in 2017 of West Kunlun Shan.Compared to GLIMS(Global Land Ice Measurements from Space Project)data,glacier area variation between 2010 and 2017 were analyzed.Sentinel-1 Level 1 GRD(Ground Range Detected)data were used to estimate glacier surface velocity from autumn of 2014 to autumn of 2017.MOD MOD10A1&MYD10A1 data were used to calculate the annual minimum albedo of glaciers.Normalized Difference Snow Index,coherence and slope were used to identify debris-covered glacier by means of rule based object-oriented image classification method.The result was well,and the area error was 5.32%,which verified the feasibility of using coherence calculated from microwave remote sensing data and optical data to extract debris-covered glacier.Glacier area was 3008.21 kilometer square(clear glacier was 2997.55 km2 and debris-covered glacier was 10.65 km2)in 2017.Compared to 2010,clear glacier increased by 1.11%,indicating that glacier area keeps stable in West Kunlun Shan.The area of debris-covered glacier increased a lot,which speeds up the melting of glaciers under.The Alakeshayi Glacier became a surging glacier,advanced 1245 meter in seven years.Based on Sentinel-IA TOPSAR image intensity,feature tracking was used to estimate the seasonal glacier surface velocity.The total mean error was 7.26 m/yr.Error was larger in summer.Glacier surface velocity was ranged from 10 to 400 m/yr.The annual average velocity of surging glaciers(>50 m/yr)were higher than that of normal glaciers(20-40 m/yr).Velocity of midstream was higher than other parts in normal glaciers,while velocity of glacier snout was higher in a surging glacier.The glacier surface velocity showed a decreasing trend from 2 015 to 2017.Velocity in summer was higher than velocity in other seasons by twenty-five percent.Surging glaciers showed a different temporal characteristic that velocity in winter was maximum.Results showed that annual minimum albedo of typical glaciers go downward slightly during 2002 and 2017,except for Chongce Glacier.It should be noted that the annual minimum albedo experiences a large fluctuation from 2004 to 2007.The spatial distribution of glacier albedo is very similar to that of glacier height,and glacier albedo increased with altitude.