Influence of landscape and hydrological factors on stream-air temperature relationships at regional scale
Influence of landscape and hydrological factors on stream-air temperature relationships at regional scale
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DOI：
10.1002/hyp.13608
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发表时间：
2019-11-05
影响因子：
3.2
通讯作者：
Hannah, David M.
中科院分区：
文献类型：
--
作者：
Beaufort, Aurelien;Moatar, Florentina;Hannah, David M.
确定河流温度（Tw）变化的主要控制因素对于对气候和其他变化驱动因素敏感的目标河流非常重要。基于气温与温度的关系，可以用河流的热敏感性来定量分析河流对未来气候变化的敏感性。本研究旨在使用4年（2008-2012年）的每小时数据比较位于法国大型集水区（110，000 km（2））内的各种温带溪流的TS，并对具有相似热变率的站点进行聚类，从而确定在区域尺度上修改TS的环境关键驱动因素。进行了两个连续的分类：（a）第一个基于Ta-Tw关系度量，包括TS和（B）第二个建立一个选择的环境变量和集群的站之间的联系。根据每周的Ta-Tw关系，第一个分类确定了四个热制度与不同的年度Tw的幅度和振幅相比，Ta。第二种分类方法是基于分类和回归树的方法，成功地将每个热状况与不同的环境控制因素联系起来。受地下水流入和阴影影响的溪流是最温和的，TS最低，Tw的年振幅约为Ta年振幅的一半。相反，位于距水源距离较远且不（或轻微）受地下水流入或阴影影响的大型溪流上的站点显示出最高的TS，因此，它们对气候非常敏感。这些发现对指导流域管理者和其他利益相关者在气候变暖和全球变化的背景下实施热调节措施具有重要意义。
Identifying the main controlling factors of the stream temperature (Tw) variability is important to target streams sensitive to climate and other drivers of change. The thermal sensitivity (TS), based on relationship between air temperature (Ta) and Tw, of a given stream can be used for quantifying the streams sensitivity to future climate change. This study aims to compare TS for a wide range of temperate streams located within a large French catchment (110,000 km(2)) using 4 years of hourly data (2008-2012) and to cluster stations sharing similar thermal variabilities and thereby identify environmental key drivers that modify TS at the regional scale. Two successive classifications were carried out: (a) first based on Ta-Tw relationship metrics including TS and (b) second to establish a link between a selection of environmental variables and clusters of stations. Based on weekly Ta-Tw relationships, the first classification identified four thermal regimes with differing annual Tw in terms of magnitude and amplitudes in comparison with Ta. The second classification, based on classification and regression tree method, succeeded to link each thermal regime to different environmental controlling factors. Streams influenced by both groundwater inflows and shading are the most moderated with the lowest TS and an annual amplitude of Tw around half of the annual amplitude of Ta. Inversely, stations located on large streams with a high distance from source and not (or slightly) influenced by groundwater inflows nor shading showed the highest TS, and so, they are very climate sensitive. These findings have implications for guiding river basin managers and other stakeholders in implementing thermal moderation measures in the context of a warming climate and global change.