Quantifying changes and trends in glacier area and volume in the Austrian Otztal Alps (1969-1997-2006)
Quantifying changes and trends in glacier area and volume in the Austrian Otztal Alps (1969-1997-2006)
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DOI：
10.5194/tc-3-205-2009
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发表时间：
2009-01-01
期刊：
影响因子：
5.2
通讯作者：
Kuhn, M.
中科院分区：
文献类型：
--
作者：
Abermann, J.;Lambrecht, A.;Kuhn, M.
在这项研究中，我们采用一种简单可靠的方法，利用 2006 年以来的高分辨率 LIDAR（光探测和测距）DEM（数字高程模型）来得出冰川面积和体积的最新变化。与两个现有的冰川清单（1969 年和 1997 年）一起，新数据集使我们能够量化过去 37 年在三个日期的面积和体积变化。奥茨塔尔阿尔卑斯山 (Otztal Alps) 的 81 座冰川（116 公里(2)）已完成此项工作，该冰川几乎占奥地利冰川面积的三分之一。冰川面积和体积急剧减少，各个尺寸等级之间存在显着差异。 1997 年至 2006 年间，总面积减少了 10.5 km(2)，即 8.2%。体积减少了 1.0 km(3)，平均厚度变化为 -8.2 m。三个可比清单的可用性允许对冰川变化进行全面的大小和海拔相关分析，但缺乏高时间分辨率。为了比较两个不同时期（1969年至1997年和1997年至2006年）之间的变化率，我们在本研究中提出了两种方法：a）估计平均总体变化率（包括提前期）和b）通过使用附加信息（长度变化和质量平衡测量）来提取净后退期。对由此产生的加速因子的分析表明，体积和平均厚度变化的回退速度明显大于面积变化的速度。
In this study we apply a simple and reliable method to derive recent changes in glacier area and volume by taking advantage of high resolution LIDAR (light detection and ranging) DEMs (digital elevation models) from the year 2006. Together with two existing glacier inventories (1969 and 1997) the new dataset enables us to quantify area and volume changes over the past 37 years at three dates. This has been done for 81 glaciers (116 km(2)) in the Otztal Alps which accounts for almost one third of Austria's glacier extent. Glacier area and volume have reduced drastically with significant differences within the individual size classes. Between 1997 and 2006 an overall area loss of 10.5 km(2) or 8.2% occurred. Volume has reduced by 1.0 km(3) which accounts for a mean thickness change of -8.2 m. The availability of three comparable inventories allows a comprehensive size and altitude dependent analysis of glacier changes but lacks a high temporal resolution. For the comparison of rates of changes between the two different periods (1969 to 1997 with 1997 to 2006) we propose two approaches in this study: a) to estimate mean overall rates of changes (including a period of advance) and b) to extract periods of net-retreat by using additional information (length change and mass balance measurements). Analysis of the resulting acceleration factors reveals that the retreat of volume and mean thickness changes has accelerated significantly more than that of area changes.