Flood-related contamination in catchments affected by historical metal mining: an unexpected and emerging hazard of climate change.
Floods in catchments affected by historical metal mining result in the remobilisation of large quantities of contaminated sediment from floodplain soils and old mine workings. This poses a significant threat to agricultural production and is preventing many European river catchments achieving a 'good chemical and ecological status', as demanded by the Water Framework Directive. Analysis of overbank sediment following widespread flooding in west Wales in June 2012 showed that flood sediments were contaminated above guideline pollution thresholds, in some samples by a factor of 82. Most significantly, silage produced from flood affected fields was found to contain up to 1900 mg kg(-1) of sediment associated Pb, which caused cattle poisoning and mortality. As a consequence of climate related increases in flooding this problem is likely to continue and intensify. Management of contaminated catchments requires a geomorphological approach to understand the spatial and temporal cycling of metals through the fluvial system.
Centre for Catchment and Coastal Research and River Basin Dynamics and Hydrology Research Group, Department of Geography and Earth Sciences, Aberystwyth University, Ceredigion SY23 3DB, United Kingdom.
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Foulds
Centre for Catchment and Coastal Research and River Basin Dynamics and Hydrology Research Group, Department of Geography and Earth Sciences, Aberystwyth University, Ceredigion SY23 3DB, United Kingdom.
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Brewer
Centre for Catchment and Coastal Research and River Basin Dynamics and Hydrology Research Group, Department of Geography and Earth Sciences, Aberystwyth University, Ceredigion SY23 3DB, United Kingdom.
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Macklin
Institute of Biological, Environmental and Rural Sciences, Animal Systems Research Group, Aberystwyth University, Ceredigion SY23 3FG, United Kingdom.
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Haresign
Centre for Catchment and Coastal Research and River Basin Dynamics and Hydrology Research Group, Department of Geography and Earth Sciences, Aberystwyth University, Ceredigion SY23 3DB, United Kingdom.
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Betson
Centre for Catchment and Coastal Research and River Basin Dynamics and Hydrology Research Group, Department of Geography and Earth Sciences, Aberystwyth University, Ceredigion SY23 3DB, United Kingdom.
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Rassner
D000383:Agriculture; D057231:Climate Change; D004784:Environmental Monitoring; D004787:Environmental Pollution / Q000706:statistics & numerical data; D055868:Floods; D019015:Geologic Sediments / Q000737:chemistry; D008670:Metals / Q000032:analysis*; D008906:Mining; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis*; D014852:Wales; D014874:Water Pollutants, Chemical / Q000032:analysis
D008670:Metals; D012987:Soil; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical
Central Wales Orefield; Climate change; Contamination; Floods; Geomorphology; Metal mining