Flood prevention measures need closer monitoring
Natural measures to manage river flooding can play a valuable role in flood prevention, but a lack of monitoring means their true potential remains unclear, researchers say.
A team of experts, including Professor Joseph Holden at the University of Leeds, has compiled the evidence on natural flood management in the UK, in order to better inform policy decisions and show where crucial gaps in knowledge lie.
The authors say natural measures have proved useful at preventing flooding after minor rainstorms, and can be a worthwhile component of a larger package of flood prevention measures. For measures such as tree planting which aim to change the way rainfall runs off the land, the evidence of the impact on flooding is mixed. Meanwhile, measures to restore natural floodplains by “making room for the river”, for example by removing flood walls and other obstacles, have been shown to reduce flood water levels.
Natural flood management is an area of increasing interest for policy makers, but its implementation can present a complex balancing act between the needs of different groups, including the public, farmers and land owners. Mixed messages about the efficacy and scalability of natural flood management measures add to the uncertainty surrounding their benefits.
Professor Holden, Director of water@leeds and leader of the Natural Environment Research Council’s Integrated Catchment Solutions Programme (iCASP) at the University’s School of Geography, said: “The 2015 Boxing Day floods proved yet again the cost and the danger of extreme floods in the UK. Reactionary measures to prevent flooding may not provide the defences needed as climate change continues to affect our weather and instances of extreme flooding increase.
“We need collaborative approaches to build knowledge and evidence to support the use of natural flood management as part of wider integrated solutions. Programmes like iCASP that involve joined-up thinking and planning across all aspects of river catchment systems will be invaluable in evaluating and establishing the best possible strategies for flood management.”
The review and assessment of scientific evidence about natural flood monitoring came from a variety of sources, ranging from field data to model projections and expert opinion. The findings are published today in Proceedings of the Royal Society.