In July 2021, London was hit by two huge thunderstorms in just a few days, bringing rainfall that was torrential even by UK standards.
Some parts of the city saw twice the average rainfall for July within two hours, and the resulting flash floods caused major disruption including school closures, hospital evacuations and the closure, or partial closure, of more than 30 London Underground stations.
Insurance claims were more than £281 million. But the true cost was much higher because the indirect impacts of flood are both far-reaching and more difficult to quantify. If a busy high street is flooded, loss of footfall leads to loss of business, disrupted supply chains, lost revenue, higher costs, devalued assets… and so on.
Transport systems are a good illustration of how the impacts of flood can stack up. An underground transport network is made up of hundreds or thousands of assets, like nodes that are all connected. It only takes one node to fail for whole stretches of the network to be affected. And it doesn’t stop there. Above ground, station closures lead to heavier traffic, longer road journeys, reduced productivity, higher costs, lost revenue… and so on.
DIVE RIGHT IN
Sign up to our newsletter
The complexity of all this is a major challenge for professionals tasked with analyzing flood risk. But more advanced flood models and more granular data are making it easier to assess infrastructure as a network rather than individual locations and get a wider understanding of the costs, both direct and indirect.
This “systems” approach is the subject of a recent Engineering Matters podcast episode, which talks about an innovative project where hazard data, publicly available traffic and other data were used to assess risk across the New Jersey transportation system.
It’s a story that illustrates how, when it comes to flooding, everything is connected – climate change and weather events, the cascading impacts and costs. But, on a more uplifting note, it also shows how making connections – between engineers and scientists, public bodies and private businesses – will help us build resilience.
Listen to the Engineering Matters podcast episode Networks under water: transport, flooding and resilience
This article has been shared with the kind permission of Fathom
You can listen to more episodes of the Engineering Matters podcasts here
[Main image : Kryuchka Yaroslav / shutterstock.com]