Using Isotopic and Geochemical Tracers to Determine the Contribution of Glacier-Snow Meltwater to Streamflow in a Partly Glacierized Alpine-Gorge Catchment in Northeastern Qinghai-Tibet Plateau
Using Isotopic and Geochemical Tracers to Determine the Contribution of Glacier-Snow Meltwater to Streamflow in a Partly Glacierized Alpine-Gorge Catchment in Northeastern Qinghai-Tibet Plateau
复制标题
利用同位素和地球化学示踪剂确定青藏高原东北部部分冰川化高山峡谷流域冰川雪融水对径流的贡献
DOI：
10.1029/2018jd028683
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发表时间：
2018-09-27
影响因子：
4.4
通讯作者：
Liu, Yanguang
中科院分区：
文献类型：
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作者：
Chang, Qixin;Ma, Rui;Liu, Yanguang
与北极和亚北极流域相比，我们对青藏高原部分冰川化的高山峡谷源头地区冰川和多孔含水层水文功能的认识仍然有限。在这里，我们研究的影响冰川和地下水储存的变化暖季（6月至9月）排放葫芦沟流域，高山峡谷的河源，3%的冰川覆盖率，通过量化的时间和规模的贡献的冰川雪融水，基流，和雨水径流使用三分量过程线分离模型。据发现，基流是暖季径流的最大组成部分（55 +/- 2%），而冰川雪融水也有显着的贡献（30 +/- 10%），尽管非常低的冰川覆盖。我们认为，冰川流出的水主要是由融化的短期和中期储存（即，冰川上的雪），这导致了温暖季节融水对溪流的贡献很大，以及强降水事件后融水排放的高峰。皮埃蒙特平原的多孔含水层可能是暖季储存地下水的主要水库，这解释了暖季基流贡献的总体增加趋势。与此相反，在高山的冰碛石和岩屑沉积物，允许地下水通过他们迅速，因此是负责的基流贡献量强降雨事件的明显反应。研究结果表明，小型山地冰川和多孔含水层在青藏高原东北部高山峡谷流域的水文调节中可能发挥比预期更大的作用。
Compared with arctic and subarctic catchments, our knowledge about the hydrological functions of glaciers and porous aquifers is still limited for the partly glacierized alpine-gorge headwaters in the Qinghai-Tibet Plateau. Here we examine the impact of glacial and groundwater storage on the variability of warm-season (June to September) discharge from the Hulugou catchment, an alpine-gorge headwater with 3% glacial coverage, by quantifying the timing and magnitude of contributions of glacier-snow meltwater, baseflow, and rainwater to streamflow using a three-component hydrograph separation model. It is found that baseflow was the largest component (55 +/- 2%) of warm-season streamflow while glacier-snow meltwater also contributed significantly (30 +/- 10%) despite of the very low glacial coverage. We suggest that the water flowing out of glaciers was mainly supplied by the melting short- and intermediate-term storages (i.e., snow over glaciers), which led to the high meltwater contribution to streams during the warm season and the high peaks of meltwater discharge following heavy precipitation events. The porous aquifers in piedmont plain may serve as major reservoirs that store a growing body of groundwater during the warm season, which explains the general increasing trend of baseflow contribution during this period. The moraine and talus deposits in high mountains, by contrast, allow groundwater to pass through them quickly and therefore being responsible for the obvious responses of baseflow contribution amount to heavy rainfall events. Our findings suggest that small mountain glaciers and porous aquifers may play a greater role than expected in hydrological regulation in the alpine-gorge catchments of northeastern Qinghai-Tibet Plateau.