ABSTRACT The Mendoza River streamflow, South America (∼32 °S), derives almost exclusively from winter snow precipitation falling in the Andes. Almost 70% of the water feeding the river originates in the Cordillera Principal geological province. In addition to the snow that precipitates in this area, there are 951 cryoforms providing meltwater to the upper catchment. Given the high inter-annual variability of snowfall and the megadrought affecting the region since 2010, it is crucial to quantify the contribution from different water sources buffering the Mendoza River runoff. Combining instrumental records of streamflow from glaciers and rivers, meteorological data, remote sensing of snow-covered areas and ionic and stable isotope analysis of different water sources, this study attempts to understand the hydrological contribution of different water sources to the basin. We demonstrated for the first time the relevance of different water sources in addition to snow in a dry period. During the melting season, 65% of the streamwaters originated from the glaciers (i.e. 50 and 15% from glaciers and rock glaciers, respectively), representing a higher proportion compared to snowmelt (17%). Groundwater input showed relatively large contributions, averaging 18%. This work offers information to develop adaptation strategies for future climate change scenarios in the region.

中文翻译：

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使用稳定水同位素对门多萨河流域上游的初雪、冰川和地下水贡献进行量化

摘要 南美洲 (~32 °S) 的门多萨河水流几乎完全来自安第斯山脉的冬季降雪。几乎 70% 的河流水源来自科迪勒拉主要地质省。除了在该地区沉淀的雪外，还有 951 个冰冻形态为上流域提供融水。鉴于自 2010 年以来降雪的高年际变化和影响该地区的特大干旱，量化不同水源缓冲门多萨河径流的贡献至关重要。结合冰川和河流径流的仪器记录、气象数据、雪覆盖区遥感以及不同水源的离子和稳定同位素分析，本研究试图了解不同水源对流域的水文贡献。我们首次证明了干旱时期除雪外不同水源的相关性。在融化季节，65% 的河水来自冰川（即分别来自冰川和岩石冰川的 50% 和 15%），比融雪（17%）的比例更高。地下水输入贡献较大，平均为18%。这项工作为制定该地区未来气候变化情景的适应战略提供了信息。50% 和 15% 分别来自冰川和岩石冰川），与融雪 (17%) 相比，这一比例更高。地下水输入贡献较大，平均为18%。这项工作为制定该地区未来气候变化情景的适应战略提供了信息。50% 和 15% 分别来自冰川和岩石冰川），与融雪 (17%) 相比，这一比例更高。地下水输入贡献较大，平均为18%。这项工作为制定该地区未来气候变化情景的适应战略提供了信息。