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Water quality and climate change. Dr Glenn Watts Evidence Directorate 19 March 2011. Structure. Drivers of change in water quality Possible impacts Modelling - scale and thresholds Implications for adaptation. Drivers – temperature. 2080s medium emissions Source UKCP09. Rainfall.
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Water quality and climate change Dr Glenn Watts Evidence Directorate 19 March 2011
Structure Drivers of change in water quality Possible impacts Modelling - scale and thresholds Implications for adaptation
Drivers – temperature 2080s medium emissions Source UKCP09
Rainfall 2080s, medium emissions Source UKCP09
Winter flows 2050s medium emissions, long term average changes Source CEH – Environment Agency “future flows”
Summer flows 2050s medium emissions, long term average changes Source CEH – Environment Agency “future flows”
Possible impacts of climate change on water quality Mobility and dilution of contaminants Chemical reaction rates Sediment mobilisation, transport and deposition
Impacts in Wales Urban discharges Flashy rivers Reduced dilution Agriculture Nutrient leaching Uplands Dissolved organic carbon and colour Sediment loads and deposition Acidification – from intense rainfall and droughts Lakes Temperature and eutrophication Mine waste mobilisation
Modelling questions: scale field catchment reach
Modelling questions:thresholds Do current approaches cope with changes of state? Empirical and conceptual models response State change threshold input
Climate change adaptation Uncertainty cascade Climate model Hydrological model Chemical model Ecosystem model
Approaches to adaptation Best estimate plus uncertainty Scenario planning – exploring risk tolerances Probabilistic approaches Climate sensitivity
Why examine the impact of climate change on water quality? To inform effective adaptation Understand possible impacts Evaluate different management responses Improve approaches to regulation
A strategy for adaptation Willows and Connell 2002
Further research Processes and responses Thresholds and climate sensitivity Links from field to catchment scale Possible adaptation measures Catchment scale management measures
Summary & conclusions Climate change affects flow and thermal regimes Water quality response complex Questions: field scale to catchment scale thresholds and climate sensitivity Do we understand adaptation measures?