River and lake water quality: future trends
Whitehead, P.G.; Battarbee, R.W.; Crossman, J.; Elliott, J.A.; Wilby, R.; Monteith, D.T.; Kernan, M.. 2012 River and lake water quality: future trends. NERC/Centre for Ecology & Hydrology. (UNSPECIFIED) (Unpublished)Before downloading, please read NORA policies.
It is now accepted that some human-induced climate change is unavoidable. Potential impacts on water supply have received much attention, but relatively little is known about the likely impacts on water quality. Projected changes in air temperature and rainfall will affect river flows and, hence, the mobility and dilution of nutrients and contaminants. Increased water temperatures will affect chemical reaction kinetics, lake stratification, in stream process and freshwater ecological status. With increased flows there will be changes in stream power, water depths, water velocity and sediment loads. These will alter the morphology of rivers and the transfer of sediments to lakes, thereby impacting water quality and freshwater habitats in both lake and stream systems. This paper reviews the potential impacts of climate change on rivers and lakes in the UK. Widely accepted climate change scenarios suggest more frequent droughts in summer, as well as flash-flooding, leading to uncontrolled discharges from urban areas to receiving water courses and lakes. Invasion by alien species is highly likely, as is migration of species within the UK adapting to changing temperatures and flow regimes. Lower flows and reduced velocities result in higher river and lake water residence times, which will enhance the potential for algal and cyanobacterial blooms and reduce dissolved oxygen levels. Upland streams and lakes could experience altered acidification status, as well as increased dissolved organic carbon and turbidity, requiring action at water treatment plants to prevent toxic by-products entering public water supplies. Storms that terminate drought periods will flush nutrients from urban and rural areas and may cause acid pulses in acidified upland catchments. Tables 1 and 2 provide concise summaries of the expected impacts of climate change on future river and lake water quality.
|Item Type:||Report (UNSPECIFIED)|
|Programmes:||CEH Topics & Objectives 2009 onwards > Water > WA Topic 3 - Science for Water Management > WA - 3.4 - Develop novel and improved methods to enable the sustainable management of freshwaters and wetlands|
|Additional Information:||Contribution and background document for the Water Climate Impacts Report Card|
|NORA Subject Terms:||Ecology and Environment|
|Date made live:||25 Jun 2012 15:01|
Actions (login required)