by Researchers have created a detailed ‘flood map of the future’ of Britain, simulating the impact of flooding as climate change takes its toll.
It has shown that annual flood damage could increase by more than a fifth over the next century.
Unless the international commitments to reduce CO2 emissions are met.
Climate change will have a particular impact on “hotspots” where homes and businesses are at risk.
Even if climate change pledges are met – temperature rise is kept to around 1.8°C – places like south-east England, north-west England and south Wales are expected to experience significantly more flooding.
The section in the new “flood risk map” also shows places that will remain largely untouched. According to the researchers, this level of detail is crucial for planning decisions.
To create these flood risk maps, the Bristol University research team and Fathom, a company that assesses flood and climate risk, simulated all types of flooding over the coming decades.
They used information about the terrain, river flow, rainfall patterns and sea levels to create a detailed picture of how severe flood damage would be to the homes and businesses of people in England, Scotland and Wales.
They combined this with forecasts of the MET office climate for the next century.
The team is also currently modeling flooding in Northern Ireland to extend forecasts across the UK as the climate warms.
According to the Association of British Insurers, the annual cost of flood damage in the UK is currently £700m.
Fathom’s Chief Research Officer, Dr. Oliver Wing explained that understanding how this “flood risk landscape” would change in a warming world is crucial as it will be different for every community.
“Our model shows that there are many places where flood risk is increasing,” said Dr. wing “Being able to understand the communities where this is likely to happen allows us to make sound investment decisions – about flood defense structures, natural flood management, or even rescuing people from the danger zone.”
Calder Valley in West Yorkshire is one of the areas most at risk of flooding from heavy rain.
Katie Kimber, of the community volunteer group Slow the Flow, explained that the steep valley caused the river to swell quickly.
“When it happens it’s really fast – it’s a wave of destruction,” she told BBC News. “Then it’s about repairing the damage – that’s very hard for the people here, both mentally and physically.”
During the Boxing Day floods of 2015, more than 3,000 properties were inundated in the Calder Valley, causing an estimated £150million in damage.
After the cleanup, Katie and other volunteers began their own flood prevention efforts with help from the National Trust. “We essentially create speed bumps for the water running down the slope [before it gets to the homes and businesses below],” Katie explained. “We plug the canals with twigs.”
Community members are also digging diversion channels to divert and slow the water.
Calderdale is a high water hotspot on the new map. But many places are expected to change very little, or even improve when it comes to flood risk, explained Dr. wing These areas include parts of North East and Central England and East and North Scotland.
This level of detail is missing from the government’s own current efforts to measure flood risk, the scientists said.
“Current government flood maps and generally not verified by scientists,” said Dr. wing “The methods they use are not transparent.
“And every pound we spend on flood risk mitigation is a pound that could be spent on teachers, nurses, hospitals and schools, so it’s really important that it’s based on accurate science.”
The scientists add that the UK as a whole “is not well adapted to the flood risks it currently faces, let alone further increases in risk from climate change”. They hope this detailed forecast can help change that.
Back on Calderdale Hill, Katie says a better prediction would be invaluable.
“Anything to help us prepare and plan,” she said. “Because we want to keep living here – we love this area. So we have to face these challenges, especially with climate change.”
dr Wing added that the new, detailed maps could help make land-use planning decisions.
“These are things that ultimately got people in the path of flooding in the first place,” he said. “That’s something we’re seeing around the world — that the most important part of flood risk is where people are, not necessarily how the floods are changing.”
