Geodetic mass balance estimates of 49320 glaciers in the High Mountain Asia (2000-2018)

Glacier melt-water from the High Mountain Asia (HMA) is an important supply of freshwater resources for billions of humans in South and East Asia, and certainly contributes to sea level rise. However, the HMA glacier mass balance during recent decades remains debated. Geodetic method, which is based on a comparison of DEMs acquired in different times, has proven to be an effective method for estimating decade-average glacier mass balance in mountainous regions. By employing thousands of pairs of the Chinese ZY-3 stereo data and the SRTM-C DEM, we provided the geodetic estimates of glacier mass balances and glacier-wide mean surface elevation changes between 2000 and 2018 for 49320 glaciers in the HMA. Moreover, we have validated the estimated glacier mass balances by comparing our results to field measurements and previously published estimates. In the period 2000-2018, most glaciers (42410) experienced a mass loss during the studied period, whereas glacier mass gain was only extracted for 6910 glaciers. Basically, mass loss is more serious for glacier facing north than south. Moreover, glacier mass balance estimates in 1˚×1˚ grids revealed an eastward increase in glacier mass loss, which is probably related to the temporal trend in annual snowfall. Overall, total glacier mass loss of -29.3±2.6 Gt yr-1 was estimated for the entire HMA between 2000 and 2018.高亚洲地区（High Mountain Asia, HMA）的冰川融水是南亚与东亚数十亿人口重要的淡水资源供给来源，同时无疑也是海平面上升的贡献因素之一。然而近数十年来，高亚洲地区的冰川物质平衡状况仍存在诸多争议。基于不同时期获取的数字高程模型（Digital Elevation Model, DEM）比对的大地测量法，已被证实是估算山区十年尺度冰川物质平均平衡的有效手段。本研究利用数千景中国资源三号（ZY-3）立体影像对与航天飞机雷达地形测绘任务C波段数字高程模型（Shuttle Radar Topography Mission-C, SRTM-C DEM），针对高亚洲地区49320条冰川，估算得到2000年至2018年间的冰川物质平衡与全域平均表面高程变化量。此外，本研究通过将估算结果与实地观测数据及已发表的相关研究成果进行比对，完成了冰川物质平衡估算结果的验证工作。在2000至2018年的研究时段内，绝大多数冰川（42410条）表现为物质亏损，仅6910条冰川呈现物质增益。总体而言，朝向北坡的冰川物质亏损程度较南坡更为显著。此外，基于1°×1°网格的冰川物质平衡估算结果显示，冰川物质亏损程度呈向东递增的趋势，这可能与年降雪量的时间变化趋势存在关联。整体而言，2000年至2018年间整个高亚洲地区的冰川总物质亏损量估算为-29.3±2.6 吉吨每年（Gt yr⁻¹）。

搜集汇总

背景与挑战

背景概述

该数据集提供了2000年至2018年间高亚洲地区49320条冰川的大地测量质量平衡估计，使用中国ZY-3立体数据和SRTM-C DEM通过DEM比较方法计算。研究发现，大多数冰川（42410条）在此期间经历质量损失，总损失为-29.3±2.6 Gt yr-1，且损失趋势向东增加，可能与年降雪量的时间趋势相关。数据集具有10-100年的时间分辨率和10m-100m的空间分辨率，以开放访问方式提供，适用于冰川变化和气候研究。