Climate change effects on indicators of high and low river flow across Great Britain. (May 2021)

• Record Type: Journal Article
• Authors: Kay, A.L.; Griffin, A.; Rudd, A.C.; Chapman, R.M.; Bell, V.A.; Arnell, N.W.
• Is Part Of: Advances in water resources. Volume 151(2021)
• Publication Date: 2021-05
• Subjects: Climate change -- Hydrological impacts -- Rainfall-runoff -- UKCP18 -- Flood -- Drought; Hydrology -- Periodicals; Hydrodynamics -- Periodicals; Hydraulic engineering -- Periodicals; 551.48
• DOI: 10.1016/j.advwatres.2021.103909
• Languages: English
• ISSNs: 0309-1708

Abstract

Highlights: Applied grid-based hydrological model and latest UK global and regional projections. Clustering applied to highlight typical changes in high and low flows. Generally decreases in low flows and increases in high flows to end of century. Significant variation in results for different regions of Great Britain. Abstract: Changes in river flows, especially extreme high and low flows, could be a particularly important impact of climate change in terms of the hazard to people and the environment. Here, a national-scale grid-based hydrological model is applied, with ensembles of global and regional climate projections from UK Climate Projections 2018, to investigate the potential future changes in both floods and droughts in a consistent way across the whole of Great Britain (gauged and ungauged locations). Using hydrological model outputs for the climate projection ensembles, a clustering technique is applied to highlight 'typical' sets of changes in individual indicators of floods or droughts, but also to look at concurrent changes in pairs of flood and drought indicators. The results for regions across the country generally indicate decreases in low flows combined with increases in high flows up to the end of the 21st century. There is significant variation in results for different regions, with those to the south/east tending to show greater decreases in low flows and a greater range of uncertainty in the projections for high flows. A grid-based cluster analysis also shows potentially important variation within regions, likely related to catchment properties. The potential future changes in derived climate hazards, such as the frequency or severity of floods and droughts, is a key piece of information required for adaptation planning, and the consideration of potential concurrent changes in a range of related hazards/risks, rather than viewing each in isolation, could be vital to avoid maladaptation.