Climate change and urbanisation to drive huge global increase in river flood exposure

A new open data platform from the World Resources Institute reveals that by 2030, 54 million people could be exposed to river flooding.

The Analyzer's analysis of US flood risk

River flood exposure is on the rise and according to the newly released Aqueduct Global Flood Analyser, 21 million people and GDP of $96bn are currently at risk. By measuring the urban damage, affected GDP and affected population caused by river flood impacts, today and in the future, the online tool aims to raise awareness of flood risks and climate change impacts and help governments to develop cost effective flood protection systems.

"The Analyser estimates that India’s current $14 billion in GDP exposed annually could increase to $154 billion in 2030. Approximately 60 percent of that increase could be caused by socio-economic development."

Developing countries that are undergoing rapid urbanisation were found to be at highest risk with 15 such countries accounting for 80 per cent of the total exposed population. “Our analysis shows a clear trend across the world. In lower and middle-income countries, socio-economic development is expected to concentrate more people, buildings, infrastructure and other assets in vulnerable regions. So, the developing world is expected to see more GDP exposed to flood risks in 2030, driven largely by socio-economic change,” says Andrew Maddocks, communications lead for the WRI water programme.

India, for example, faces more potential change in exposed GDP than any other country. Using a middle-of-the road scenario, the Analyser estimates that India’s current $14 billion in GDP exposed annually could increase to $154 billion in 2030. Approximately 60 percent of that increase could be caused by socio-economic development.

In the developed world, Australia, Croatia, Finland, Portugal, and Israel are expected see more GDP exposed to floods in 2030, driven primarily by social-economic change. Countries like the Netherlands, Slovenia, Belgium, Ireland, and Switzerland will likely see increased GDP exposure driven primarily by climate change as the frequency and intensity of river flooding increases.

Other data to come from the Analyser includes estimates on the value of GDP protected through various levels of flood protection in three climate and socio-economic change scenarios. In the US for example assuming flood protection levels of 1 in 100 years and a medium risk change scenario, the annual affected GDP is $36.8bn with a huge $512.9bn in damage avoided thanks to flood protection measures.

By 2030 the GDP at risk is forecast to hit $89.2bn - an increase of 129%. Under the same flood protection level and risk scenario the UK currently has $667.4bn in GPD at risk with $7.1bn in damage avoided. This is set to increase by 140% to $1.6bn by 2030.

WRI co-developed the tool with four Dutch research organizations: Deltares, the Institute for Environmental Studies of the VU University Amsterdam, Utrecht University and PBL Netherlands Environmental Assessment Agency, supported by the Netherlands’ Ministry of Infrastructure and the Environment. The organisations intend for the tool to be used in the development of flood protection systems. 

“Armed with this information, decision makers will be able to prioritize risk reduction and climate adaptation projects, and implement the most viable, cost-efficient options. It will take time and significant investment, but starting now, city leaders and decision-makers in international relief organizations, local governments, and the private sectors have an informative, powerful tool for developing vital flood protection systems and ensuring the long-term safety and stability of cities worldwide,” says Maddocks.


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