1971-2014年慕士塔格-公格尔地区冰川高程变化数据集

A dataset of glacier elevation change in Muztag Ata and Kongur Tagh from 1971 to 2014

在气候变化的影响下,冰川变化将显著影响区域水循环和水资源,而冰川高程变化是反映该过程的关键指标。慕士塔格–公格尔地区位于东帕米尔高原,是我国重要冰川作用区之一。该区域不仅是目前国际冰川研究热点区域,而且是中巴经济走廊穿越区,其研究重要性日益增长。本文基于地形图、SRTM DEM和ASTER立体像对数据获取1971–2014年慕士塔格–公格尔地区冰川高程变化数据集。本数据集大致空间范围在38°N–39°N,74°40′E–75°40′E内,覆盖434条冰川,冰川总面积为998.8 km2,存储为GeoTIFF格式(32位浮点型),空间分辨率为30 m。为尽可能消除DEM空间匹配误差和由不同空间分辨率引起的误差,利用数据间的误差与地形因子之间的关系进行校正,同时估算了SRTM C波段对冰雪的穿透深度,提高了结果的精度。非冰川区残差统计分析表明,本数据集冰川高程变化误差为0.02~0.07 m a-1。本数据集可以作为帕米尔高原山地冰川冰量变化的本底调查资料,为该区域山地冰川物质平衡研究提供基础数据支撑。另外,本数据集与气候、水文等数据进行综合分析,可以揭示冰川–气候–水文之间的定量联系,深化冰川对气候变化响应机理及影响的科学认识,进一步了解该地区冰川变化的水资源效应。

While climate-driven glacier change significantly impacts regional water resources,particularly the hydrological cycle,glacier elevation change is a key indicator of climate change.As a major glacier region in eastern Pamir,China,the Muztag Ata and Kongur Tagh region is not only a hot area for glacier studies,but also a part of the China-Pakistan Economic Corridor.It shows growing importance in glacier research.In this study,glacier elevation changes were derived from topographic maps,SRTM DEM and ASTER images from 1971 to 2014.Within its spatial extent(38°N–39°N,74°40′E–75°40′E),the region covers 434 glaciers totaling an area of 998.8 km2.The resulted data,with a spatial resolution of 30 m,were stored in GeoTiff format in 32-bit floating point.To mitigate influences of the relative errors between DEMs from the generating procedures,we corrected these errors before estimating elevation change using the relation between error and terrain factor.We also evaluated the penetration depth of the C-band radar beam of SRTM into snow and ice.A statistical analysis of the residual error of elevation change in non-glacial areas indicates that the results have an overall accuracy of about 0.02~0.07 m a-1.The dataset can serve as the basis for investigating the region’s glacier volume change,providing statistical support for research on glacier mass balance.In addition,when used in combination with climatic and hydrological data,the dataset can help reveal the quantitative relationship between glaciers,climate and hydrology.It promotes a scientific understanding of the glaciers’responding mechanism to climate changes,and the region’s water effects of glacial changes.