近日,加拿大达尔豪斯大学Kurylyk, Barret L团队,提出全球地下水变暖可以归因于气候变化这一新观点。相关论文于2024年6月4日发表在《自然—地球科学》杂志上。
据了解,含水层储存了最多的未冻结淡水,这使得地下水对地球上的生命生存至关重要。令人惊讶的是,人们对地下水在时空尺度上如何应对地表变暖知之甚少。
着眼于扩散热输运,研究人员模拟了全球范围内当前和预测的地下水温度。保守估计,在中等排放途径下,地下水位深处的地下水(不包括永久冻土区)预计在2000年至2100年之间平均变暖2.1°C。然而,由于气候变化和地下水位深度的空间变异性,区域浅层地下水变暖模式存在很大差异。
预计在山区(如安第斯山脉或落基山脉)比率最低。研究阐明了地下水温度的升高会影响河流的热状态、地下水依赖的生态系统、水生生物地球化学过程、地下水质量和地热潜力。结果表明,按照中等排放路径,到2100年,预计将有7700万至1.88亿人生活在,地下水温度超过任何国家设定的最高饮用水温度阈值的地区。
附:英文原文
Title: Global groundwater warming due to climate change
Author: Benz, Susanne A., Irvine, Dylan J., Rau, Gabriel C., Bayer, Peter, Menberg, Kathrin, Blum, Philipp, Jamieson, Rob C., Griebler, Christian, Kurylyk, Barret L.
Issue&Volume: 2024-06-04
Abstract: Aquifers contain the largest store of unfrozen freshwater, making groundwater critical for life on Earth. Surprisingly little is known about how groundwater responds to surface warming across spatial and temporal scales. Focusing on diffusive heat transport, we simulate current and projected groundwater temperatures at the global scale. We show that groundwater at the depth of the water table (excluding permafrost regions) is conservatively projected to warm on average by 2.1°C between 2000 and 2100 under a medium emissions pathway. However, regional shallow groundwater warming patterns vary substantially due to spatial variability in climate change and water table depth. The lowest rates are projected in mountain regions such as the Andes or the Rocky Mountains. We illustrate that increasing groundwater temperatures influences stream thermal regimes, groundwater-dependent ecosystems, aquatic biogeochemical processes, groundwater quality and the geothermal potential. Results indicate that by 2100 following a medium emissions pathway, between 77 million and 188 million people are projected to live in areas where groundwater exceeds the highest threshold for drinking water temperatures set by any country.
DOI: 10.1038/s41561-024-01453-x
Source: https://www.nature.com/articles/s41561-024-01453-x