Contribution of glacier melt to stream runoff: if the climatically extreme summer of 2003 had happened in 1979…
Contribution of glacier melt to stream runoff: if the climatically extreme summer of 2003 had happened in 1979…
复制标题
冰川融化对河流径流的贡献：如果 2003 年气候极端的夏季发生在 1979 年……
作者：
G. Koboltschnig;W. Schöner;M. Zappa;H. Holzmann
摘要本文以奥地利阿尔卑斯山区一个小而高度冰川化的集水区为研究对象，模拟了2003年夏季极端干热条件下的径流，模拟了两个不同的冰川范围：2003年冰川范围和大29%的1979年冰川范围。采用高时间分辨率的水文水平衡模式PREVAH模拟径流。为此，基于数字高程模型和土地覆盖数据，将流域划分为水文响应单元。该模型是由位于集水区最高点（3106ma.s.l.）的Hoher Sonnblick天文台的气象数据驱动的。我们感兴趣的是冰川范围的变化对年和月水平衡以及每小时流量的水文曲线的影响。2003年的模拟结果和1979年的模拟结果显示，7 - 8月的径流主要不同，这取决于更高的融冰贡献。由于相同的气象输入，两种模拟计算的积雪和融雪量相同。1979年的年排放量将比2003年高出12%，每小时的径流量将比2003年高出35%。
Abstract This paper presents a comparative study at a small and highly glacierized catchment area in the Austrian Alps, where runoff under the extreme hot and dry conditions of summer 2003 was simulated based on two different glacier extents: the 2003 glacier extent and the 29% larger 1979 extent. Runoff was simulated applying the hydrological water balance model PREVAH at a high temporal resolution. For this purpose, the catchment area was subdivided into hydrological response units based on digital elevation model and land-cover data. The model was driven by meteorological data from the observatory at Hoher Sonnblick, situated at the highest point of the catchment area (3106ma.s.l.). We were interested in the effect the change in glacier extent would have on the annual and monthly water balance and the hydrograph of hourly discharges. Results of the 2003 and the hypothetical 1979 simulation show main differences in runoff for the period July–August depending on a higher ice-melt contribution. Due to the same meteorological input, both simulations calculate the same snow accumulation and snowmelt. Annual discharge in 1979 would have been 12% higher and hourly runoff up to 35% higher than in 2003.