This article reports modeled ice thickness distribution and total ice volume of the 65 selected glaciers(>0.5 km^2)of Chandra basin,located in the Western Himalayas.This is a first-of-its-kind study that gives deta...This article reports modeled ice thickness distribution and total ice volume of the 65 selected glaciers(>0.5 km^2)of Chandra basin,located in the Western Himalayas.This is a first-of-its-kind study that gives detailed insights about the current ice thickness distribution at an individual glacier level in the Western Himalayas.The estimates are obtained using an optimally parameterized Glab Top2_IITB[Glacier Bed Topography Indian Institute of Technology Bombay(IITB)version]model with highresolution Digital Elevation Model(DEM)as an input.The total estimated volume of all the 65 selected glaciers is about 55.32 km^3 covering a total area of about 591.03 km^2.Using hypsometric analysis,it is found that the maximum amount of ice volume,i.e.,about 12.79 km^3,is currently residing at the elevation range of 5200–5400 m a.s.l.Ice thickness estimates obtained in the current study are compared with the ensemble estimates obtained in the Global Glacier Thickness Initiative(G2TI)project for three large glaciers,namely,Bada Shigri,Samudra Tapu,and Gepang Gath glaciers.The obtained results indicate that the difference between both the studies is marginal in terms of mean ice thickness and maximum ice thickness estimates except Samudra Tapu glacier.Moreover,the uncertainty of the estimated glacier ice volume from this study is about±15%whereas,from the G2TI project,it is about 25%.The main reasons for the difference could be the quality of the inputs used,model structure,model parameterization as well as the time stamp of the input used.The obtained results from this study indicate that the use of appropriate shape factor and better DEM would result in more reliable glacier ice thickness estimates even by using a simple slopedependent model like Glab Top2_IITB.展开更多
冰川物质平衡作为气候变化的敏感指标,对于区域水资源管理,冰川灾害防治以及全球海平面变化预测具有重要意义。随着全球变暖加剧,自2000年来祁连山西段冰川消融加速,然而近年来该地区尤其是老虎沟12号冰川的年际物质平衡变化仍知之甚少...冰川物质平衡作为气候变化的敏感指标,对于区域水资源管理,冰川灾害防治以及全球海平面变化预测具有重要意义。随着全球变暖加剧,自2000年来祁连山西段冰川消融加速,然而近年来该地区尤其是老虎沟12号冰川的年际物质平衡变化仍知之甚少。本文利用WorldView光学立体测绘、SRTM和TanDEM-X双站InSAR生成的多源DEM数据,采用DEM差分法分别获得了2013年—2014年、2014年—2015年祁连山西段年际冰厚变化速率和2000年—2015年平均冰厚变化速率,同时获得了相应时段的冰川物质平衡结果。在此基础上以老虎沟12号冰川为例,估算了2013年—2014年、2014年—2015年和2000年—2015等3个时间段的冰川物质平衡变化速率,并分析了降水和气温变化对物质平衡变化的影响。结果表明:2013年—2014年、2014年—2015年祁连山西段冰厚变化速率为-0.35±0.034 m和-0.028±0.004 m,物质平衡变化速率分别为-0.27±0.014 m w.e./a和-0.024±0.084 m w.e./a。2000年—2015年老虎沟12号冰川平均物质平衡为-0.013±0.02 m w.e./a,冰川处于消融状态。冰川亏损速率由2013年—2014年的-0.33±0.04 m w.e./a减缓至2014年—2015年的-0.036±0.09 m w.e./a,这主要与2015年降水增多有关。本文验证了高质量的光学立体测绘卫星DEM数据在求解山地冰川年际物质平衡的可行性。展开更多
基金the funding support provided by the Indian Institute of Technology Bombay,Centre of Excellence in Climate Studies(IITB-CECS)project of the Department of Science and Technology(DST),New Delhi,India。
文摘This article reports modeled ice thickness distribution and total ice volume of the 65 selected glaciers(>0.5 km^2)of Chandra basin,located in the Western Himalayas.This is a first-of-its-kind study that gives detailed insights about the current ice thickness distribution at an individual glacier level in the Western Himalayas.The estimates are obtained using an optimally parameterized Glab Top2_IITB[Glacier Bed Topography Indian Institute of Technology Bombay(IITB)version]model with highresolution Digital Elevation Model(DEM)as an input.The total estimated volume of all the 65 selected glaciers is about 55.32 km^3 covering a total area of about 591.03 km^2.Using hypsometric analysis,it is found that the maximum amount of ice volume,i.e.,about 12.79 km^3,is currently residing at the elevation range of 5200–5400 m a.s.l.Ice thickness estimates obtained in the current study are compared with the ensemble estimates obtained in the Global Glacier Thickness Initiative(G2TI)project for three large glaciers,namely,Bada Shigri,Samudra Tapu,and Gepang Gath glaciers.The obtained results indicate that the difference between both the studies is marginal in terms of mean ice thickness and maximum ice thickness estimates except Samudra Tapu glacier.Moreover,the uncertainty of the estimated glacier ice volume from this study is about±15%whereas,from the G2TI project,it is about 25%.The main reasons for the difference could be the quality of the inputs used,model structure,model parameterization as well as the time stamp of the input used.The obtained results from this study indicate that the use of appropriate shape factor and better DEM would result in more reliable glacier ice thickness estimates even by using a simple slopedependent model like Glab Top2_IITB.
文摘冰川物质平衡作为气候变化的敏感指标,对于区域水资源管理,冰川灾害防治以及全球海平面变化预测具有重要意义。随着全球变暖加剧,自2000年来祁连山西段冰川消融加速,然而近年来该地区尤其是老虎沟12号冰川的年际物质平衡变化仍知之甚少。本文利用WorldView光学立体测绘、SRTM和TanDEM-X双站InSAR生成的多源DEM数据,采用DEM差分法分别获得了2013年—2014年、2014年—2015年祁连山西段年际冰厚变化速率和2000年—2015年平均冰厚变化速率,同时获得了相应时段的冰川物质平衡结果。在此基础上以老虎沟12号冰川为例,估算了2013年—2014年、2014年—2015年和2000年—2015等3个时间段的冰川物质平衡变化速率,并分析了降水和气温变化对物质平衡变化的影响。结果表明:2013年—2014年、2014年—2015年祁连山西段冰厚变化速率为-0.35±0.034 m和-0.028±0.004 m,物质平衡变化速率分别为-0.27±0.014 m w.e./a和-0.024±0.084 m w.e./a。2000年—2015年老虎沟12号冰川平均物质平衡为-0.013±0.02 m w.e./a,冰川处于消融状态。冰川亏损速率由2013年—2014年的-0.33±0.04 m w.e./a减缓至2014年—2015年的-0.036±0.09 m w.e./a,这主要与2015年降水增多有关。本文验证了高质量的光学立体测绘卫星DEM数据在求解山地冰川年际物质平衡的可行性。
