Local flood protection efforts inadequate to meet growing climate change threat
As extreme rain events become more frequent, European efforts to address the threat of river flooding should focus on adapting to impacts rather than trying to avoid them, according to a new study published in the journal Climatic Change.
The ressearch, led by scientists with European Commission Joint Research Centre, studied the benefits of four adaptation measures based on the increasing flood risk projected by climate models, including reduction of the peak flows through water retention, reduction of vulnerability and relocation to safer areas.
They concluded that the traditional approaches that aim to increase local flood protection are not sustainable in the long term. Future strategies should be viewed at the scale of river basins and not on independent actions in specific river reaches.
The most effective measures include relocation and vulnerability reduction. Reducing vulnerability includes early warning systems, dry and wet flood proofing, and floating buildings. Such strategies could reduce the effect of uncertainty and make societies more resilient to increasing climatic extremes.
Adaptation plans aimed at increasing flood protection can help reduce the impacts of repeated small floods, but are less effective at protecting lives and communities from catastrophic floods. Further adaptation measures to reduce the peak flow should make use of natural retention capacity upstream, while rising flood protections should be seen as last resort, to compensate for the residual risk in areas where other options cannot be implemented.
The study used the high-end climate RCP8.5 scenario of the Intergovernmental Panel on Climate Change (IPCC) which assumes high levels of greenhouse gas concentrations, and foresees a global temperature rise exceeding 4?C before the end of the century. The study takes the period 1976-2005 as baseline scenario, while the benefits of implementing adaptation measures are evaluated over 2006-2100.