BioGéosciences, UMR6282 CNRS/Université de Bourgogne Franche-Comté, Dijon, France.
Department of Geoscience and Remote Sensing, Delft University of Technology, Delft, The Netherlands.
Sci Rep. 2020 Jun 26;10(1):10420. doi: 10.1038/s41598-020-67379-7.
The Mont-Blanc massif, being iconic with its large glaciers and peaks of over 4,000 m, will experience a sharp increase in summer temperatures during the twenty-first century. By 2100, the impact of climate change on the cryosphere and hydrosphere in the Alps is expected to lead to a decrease in annual river discharge. In this work, we modelled the twenty-first century evolution of runoff in the Arve river, downstream of Mont-Blanc's French side. For the first time for this region, we have forced a hydrological model with output from an ice-dynamical glacier model and 16 downscaled climate projections, under RCP4.5 and RCP8.5 scenarios. By 2100, under RCP8.5 (high-emission scenario), the winter discharge of the Arve river remains low but is expected to increase by 80% when compared to the beginning of the century. By contrast, the summer season, currently the most important discharge period, will be marked by a runoff decrease of approximately 40%. These changes are almost similar according to a scenario with a lower warming (RCP4.5) and are mostly driven by glacier retreat. These shifts will have significant downstream impacts on water quantity and quality, affecting hydroelectric generation, agriculture, forestry, tourism and aquatic ecosystems.
勃朗峰山脉以其大型冰川和 4000 米以上的山峰而闻名，预计在 21 世纪夏季气温将大幅上升。到 2100 年，气候变化对阿尔卑斯山的冰冻圈和水圈的影响预计将导致年径流量减少。在这项工作中，我们模拟了勃朗峰法国一侧下游的阿尔沃河在二十一世纪的径流量演变。对于该地区来说，我们首次利用冰动力冰川模型的输出以及 16 个下推的气候预测，在 RCP4.5 和 RCP8.5 情景下对一个水文模型进行了强制。到 2100 年，在 RCP8.5（高排放情景）下，阿尔沃河的冬季流量仍然较低，但预计与本世纪初相比将增加 80%。相比之下，目前最重要的排放期夏季，径流量将减少约 40%。根据一个变暖程度较低的情景（RCP4.5），这些变化几乎是相似的，主要是由冰川后退驱动的。这些变化将对水量和水质产生重大的下游影响，影响水电、农业、林业、旅游业和水生生态系统。
