Floods in future climates: a review

Abstract

At the global scale, the warming of the atmosphere will increase the capacity of the atmosphere to hold and accelerate the redistribution of water in the atmosphere. This suggests that flood-generating processes linked to the atmosphere are likely to increase. However, the Intergovernmental Panel on Climate Change projections of future floods involve extremely complex issues that defy simple generalisations. Warming will alter other aspects of the water cycle increasing evaporation, changing precipitation patterns and intensity, and also affecting the processes involved in surface storage of water, including snowpack generation, snowmelt, river ice break-up, and glacial melt. Many of these are active in flood generation, and changes may cause floods to decrease as well as increase. However, these processes take place not at the global scale but at relatively local scale, making generalisations about flooding in future climates difficult and uncertain. At the global scale, the role of land use is generally unresolved, but at a watershed scale, land-use effects can be as important as changes in the meteorological processes. This review shows that while meteorologically driven flooding is expected to increase in a changed climate, making a precise pronouncement regarding all floods is unwise, as many types of floods will respond differently to changing climate and that because floods are watershed scale events, these local effects will remain important. bs_bs_banner

Changes in floods and flood regimes in Canada

“…Email: dhburn@civmail.uwaterloo.ca Increases in intense precipitation are projected to occur since global air temperature increases are expected to be accompanied by the greater water-holding capacity of a warmer atmosphere; precipitation intensity increases imply increases in flooding potential (Meehl et al 2007;Kundzewicz et al 2014). Major river floods can be caused solely by intense precipitation but, generally, flood generation processes are more complex (Whitfield 2012). This is particularly true in Canada where natural factors influencing the magnitude of floods include snowmelt runoff and antecedent soil moisture; changes in these factors may cause flood magnitudes to either decrease or increase (Buttle et al 2015, this issue).…”

Rapid mapping of urban development from historic Ordnance Survey maps: An application for pluvial flood risk in Worcester

“…The increases in impervious surfaces and drainage pathways that result from urban development have shown to increase the peak discharge, volume, and frequency of river floods (e.g. Hejazi & Markus, 2009;Kázmierczak & Cavan, 2011;Villarini, Smith, Baeck, Smith, & Sturdevant-Rees, 2013;Whitfield, 2012). Similar changes are also likely to increase occurrences of pluvial flooding within the urban developments.…”

Estimating extreme river discharges in Europe through a Bayesian network

“…Available studies (Whitfield, 2012;Feyen et al, 2012; predict that the severity of floods will increase, due to changes in extreme precipitation and socio-economic development. Abundant availability of continental and global climate, land-use, and elevation data result in many studies analysing floods in a similarly large domain.…”