Geochemical and isotopic mass balances of kettle lakes in southern Quebec (Canada) as tools to document variations in groundwater quantity and quality

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• 作者：Marie Arnoux ; Florent Barbecot ; Elisabeth Gibert-Brunet…
• 关键词：Lakes ; Hydrological balance ; Groundwater ; surface water interactions ; Geochemical tracers
• 刊名：Environmental Earth Sciences
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：76
• 期：3
• 全文大小：
• 刊物类别：Earth and Environmental Science
• 刊物主题：Geology; Hydrology/Water Resources; Geochemistry; Environmental Science and Engineering; Terrestrial Pollution; Biogeosciences;
• 出版者：Springer Berlin Heidelberg
• ISSN：1866-6299
• 卷排序：76

文摘

Given increasing anthropogenic and climatic pressures on water resources, groundwater and surface water need to be better managed and preserved. As these two water stocks can be connected to each other, their evolutions are linked and need to be considered as such. However, interactions between lakes and groundwater are not well understood and, most of the time, are not taken into account. Therefore, establishing a comprehensive approach to quantify groundwater and lakes’ hydrogeochemical interactions in various settings is of foremost importance for assessing the sensitivity of lakes to groundwater evolution. In this study, small kettle lakes set in fluvioglacial deposits and that are most likely well connected to shallow unconfined aquifers are specifically targeted. Geochemistry and isotopic results highlight that groundwater flux to the lakes is generally the dominant parameter of the lake water budget. The 222Rn results in particular suggest that 38% of the studied lakes have a high proportion of groundwater in their balances. It appears that the different tracers are complementary: geochemistry is influenced by groundwater inflows, reflecting its quality and the local geology, whereas water stable isotopes correspond directly to the volumetric lake water budget, and both of these tracers are impacted by in-lake processes. Moreover, the third tracer considered, 222Rn, highlights the location of groundwater inputs in space and time. Finally, the studied kettle lakes are characterized by a short to medium flushing time by groundwater. As a result, these lakes can be highly sensitive to environmental and climate changes affecting groundwater.