Mellor Archaeological Trust, Stockport SK6, UK.
University of Salford, Manchester M5 4WT, UK.
Sci Total Environ. 2019 Mar 25;658:777-786. doi: 10.1016/j.scitotenv.2018.12.215. Epub 2018 Dec 18.
Climate change is significantly impacting lotic environments, through changes to hydrology, biodiversity and species distribution. Effects of climate change are greatest at high elevation and biota in and around glacier-fed rivers is likely, therefore, to be at great risk. How climate change influences hydrology will have great impact on river water temperature as glacier-fed rivers in Alpine environments are extremely sensitive to climatic change. This paper assesses five rivers: Four glacier-fed rivers (36.9-83.7% basin glacierisation) located in the Swiss Alps, and one located in an ice-free catchment in the Bernese Oberland, Switzerland. The aim was to assess the impact of basin characteristics on river water temperature. A distinct paradoxical relationship was identified whereby water temperature in some glacier-fed rivers was reduced during the time of highest incoming shortwave radiation receipts and high air temperature. Whether a summer cooling effect presented itself in all glacier-fed rivers within this study was researched. The key findings were that the identified summer cooling effect was not present in all rivers, despite percentage glacierisation. Percentage glacier cover has often been reported as they key determiner of water temperature in such rivers. More important was the stream dimensions, notably stream surface area. Understanding the controlling factors that influence water temperature of glacier-fed rivers will help river managers and planners in understanding how climate change will affect fisheries downstream of glaciers over the coming decades. This may allow plans to be introduced to try and mitigate warmer water temperature that will result, in some glacier-fed rivers, as the climate warms.
气候变化正在通过改变水文学、生物多样性和物种分布，对流水环境产生重大影响。气候变化的影响在高海拔地区最大，因此，冰川补给河流及其周围的生物群落在很大程度上处于危险之中。气候变化如何影响水文学将对河流水温产生重大影响，因为阿尔卑斯山环境中的冰川补给河流对气候变化极为敏感。本文评估了瑞士阿尔卑斯山的五条河流：四条冰川补给河流（流域冰川化率为 36.9-83.7%）和一条位于瑞士伯尔尼高地无冰流域的河流。目的是评估流域特征对河流水温的影响。研究发现，在一些冰川补给河流中，存在一种明显的矛盾关系，即在太阳短波辐射和高气温接收量最高的时期，河水温度反而降低。本研究调查了所有冰川补给河流是否都存在夏季降温效应。关键发现是，尽管存在冰川化率，但并非所有河流都存在所识别的夏季降温效应。冰川覆盖率通常被报道为这些河流水温的关键决定因素。更重要的是溪流的尺寸，特别是溪流的表面积。了解影响冰川补给河流水温的控制因素将有助于河流管理者和规划者了解在未来几十年中，气候变化将如何影响冰川下游的渔业。这可能会促使人们引入一些计划，试图缓解一些冰川补给河流因气候变暖而导致的水温升高问题。
