Measuring flood risk impact

Mike Woolgar | 17 Apr 2015 | Comments

New data from the World Resources Institute has revealed (source) that by 2030, 54 million people could be exposed to river flooding. It goes without saying that as populations increase, and increasingly urbanise, the density of populations and assets generally increases. Given that most towns, as engines which convert resources into wealth through manufacture, trading, adding value, services etc, were originally established on rivers and/or at the coast, such increase in density of population and assets automatically implies – even in the absence of climate change and weather volatility – an increase in the risk of damage or loss through river and/or coastal flooding as well as pluvial flooding; eg when heavy rainfall overwhelms sewer and drainage systems and causes local flooding. When you add climate change, sea level rise and the likelihood of increased and/or more intense storms the risk is expected to increase with more people affected and more property damage.

We are doing work, in Africa principally, looking at the populations at risk from river flooding disasters in order to inform disaster risk reduction policies and measures. Risk in this case does not just mean death and injury, but also the short term and longer term impacts on displaced people’s health, the fragility of these people’s ability to generate and maintain livelihoods in the face of repeated, and potentially increasing, events. Our work on Future Proofing Cities had the role of policy development and design of measures as a core issue in helping to mitigate and reduce such impacts. As the WRI report says, it will be a long road to change direction from unconstrained urban growth to controlled, managed and sustainable development.

In the UK we are also looking at more closely assessing the impacts of flooding on the economy, taking account of Treasury Green Book rules but also extending these macro measures to examine more closely real impacts on local economies, such that Local Authorities and other stakeholders can help to formulate plans to reduce pluvial/fluvial flooding impacts and hence help to reduce impacts on people’s lives and livelihoods.