Climate-change-driven deterioration of water quality in a mineralized watershed

Environmental Science & Technology
By: , and 

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Abstract

A unique 30-year streamwater chemistry data set from a mineralized alpine watershed with naturally acidic, metal-rich water displays dissolved concentrations of Zn and other metals of ecological concern increasing by 100–400% (400–2000 μg/L) during low-flow months, when metal concentrations are highest. SO4 and other major ions show similar increases. A lack of natural or anthropogenic land disturbances in the watershed during the study period suggests that climate change is the underlying cause. Local mean annual and mean summer air temperatures have increased at a rate of 0.2–1.2 °C/decade since the 1980s. Other climatic and hydrologic indices, including stream discharge during low-flow months, do not display statistically significant trends. Consideration of potential specific causal mechanisms driven by rising temperatures suggests that melting of permafrost and falling water tables (from decreased recharge) are probable explanations for the increasing concentrations. The prospect of future widespread increases in dissolved solutes from mineralized watersheds is concerning given likely negative impacts on downstream ecosystems and water resources, and complications created for the establishment of attainable remediation objectives at mine sites.

Publication type Article
Publication Subtype Journal Article
Title Climate-change-driven deterioration of water quality in a mineralized watershed
Series title Environmental Science & Technology
DOI 10.1021/es3020056
Volume 46
Issue 17
Year Published 2012
Language English
Publisher ACU Publications
Contributing office(s) Crustal Geophysics and Geochemistry Science Center
Description 9 p.
First page 9324
Last page 9332
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