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Scientists react to flood warnings issues in England and Wales following recent storms.
Prof Roger Falconer, Emeritus Professor of Water and Environmental Engineering, Cardiff University, said
Why has the flooding been so bad recently? Comments on links to climate change?
“I have been involved in flood modelling and resilience for ca. 40 years and in recent years flooding appears to have been getting worse, particularly in terms of rainfall intensity and more frequent flood events. These changes in weather patterns would appear to be as predicted by climate meteorologists and those specialising in climate change.”
“In modelling and planning for reducing flood risk then in my view, we need to study and manage the river basin as a whole, using a systems-based approach, from the upper catchments to the coast.”
How much is our infrastructure prepared for these floods and where are the weak points?
“With regard to infrastructure, we need to provide structures that will generate more storage along river basins, as well as working with nature-based solutions which can play a part in holding the water back in the upper catchments. With regard to infrastructure, an excellent example of providing extra storage is exhibited by the series of low head (ca. 10 m) earth embankment dam walls on the outskirts of Skipton (Skipton Flood Alleviation Scheme officially opened – GOV.UK (www.gov.uk) and with a large dam flooding a major part of a golf course during extreme flood events. During the storm, the flood water accumulates behind the low head dams, which then drain slowly after the storm has passed.
What can we expect in the future?
“Based on the assessment of climate specialists we can expect more extreme flood events in the future.”
Prof Ivan Haigh, Professor in Coastal Oceanography, National Oceanography Centre, University of Southampton, said:
“Flooding is the most destructive natural hazard that humanity faces. Nearly 2 billion people, a quarter of the world’s population, are exposed to the risk of flooding. In the last three months alone, there have been major flood events in New York, Hong Kong, Greece, Turkey and Bulgaria, catastrophic flooding in Libya, and now serious flooding in the UK. In the UK, flooding is the principal environmental hazard identified in the National Risk Register such that flooding is ranked as the top priority risk after a pandemic, and around 1 in 6 households are located in flood prone areas
“My heart goes out to those people and business currently affected by flooding. However, unfortunately we need to recognise that flooding is going to become even more frequent and challenging to manage in the UK and elsewhere in the coming years because of: (i) sea-level rise and changes in rainfall patterns, driven by climate change; (ii) land use and land management changes including population growth and urban encroachment into flood-prone areas; (iii) ongoing decline in the extent of natural habitats that act as a buffer to flooding, and; (iv) ageing assets because many flood defences were built >50 years ago.
“We are facing a perfect storm, and we need to act now and come together to improve the way we manage the large and growing threat of flooding in the UK, and elsewhere around the world.”
Prof Trevor Hoey, a Professor of River Science at Brunel University London and director of the Centre for Flood Risk and Resilience, said:
On why Britain is vulnerable to floods:
“On a global scale, the UK is not as vulnerable to flooding as many other parts of the world, and we do have resources to invest in flood protection. However, the UK is at risk of flooding because we are located beside a large ocean and are always going to get a lot of rain-bearing weather systems coming our way. Periodically, as over the past few months, there will be sequences of storms and prolonged rain. On top of this, we are living in an era of climate change, and there is evidence that things are getting worse as rainfall totals increase and storms become more frequent.
“While floods are natural events, our long history of using floodplains, riverbanks and coasts for farming, housing and infrastructure exposes the UK to considerable economic and social costs whenever flooding occurs. We will only increase our resilience to flooding by recognising that flood risk management involves raising awareness and adapting our own activities as well as building flood defences.”
On the government’s action on flood protection:
“Periodically, large flood events occur in the UK, and there has been a pattern over the last 20 to 30 years of major flood events being followed by government instituting reviews, to look at how we approach flood risk management. These reviews have many consistent messages about flood risk increasing and a range of approaches being required to control this risk – there is no single solution and we can never eliminate flood risk.
“One of the things that does need to be looked at in the UK context is to have that dialogue between national government, local government, and other responsible authorities so that we do the integrated planning that is proposed in all of the reviews that have been conducted. There are always recommendations about integration and co-operation, but it remains a real challenge to bring diverse bodies, who each have a range of other responsibilities, together.
“The UK does spend a lot of money on flood risk protection, and there will always be demand for additional funds. There is a challenge to ensure that all of that investment is used in a really efficient and strategic way. The National Audit Office recently highlighted a lack of spending on maintaining existing flood defences, which is a good example of where planning needs to be strategic and long-term – maintenance is not as exciting to politicians as are new schemes, but will often deliver greater value for money.
“Extreme events are by their nature unpredictable both in terms of when they will occur and where their impact will be greatest. Resilience planning must be coordinated and joined up, between all levels of government, across agencies and a wide range of stakeholders.
“The NAO has identified strategic deficiencies that need to be remedied urgently, along with co-ordinated and consistent communication with the public to ensure that risks are understood, mitigation and adaptation are undertaken and that we address the causes of risk as well as the consequences when an extreme event does occur.
“There are parallels here with the national response to COVID, and it is to be hoped that Government is listening carefully to what the ongoing inquiry is revealing about risk preparedness.”
On how we can future-proof the country when it comes to flooding:
“We must future-proof in relation to water and not just flooding. Last summer there was concern over reservoir levels in parts of the country being at their lowest on record. During the summer, we also had a lot of reports about water pollution and untreated sewage entering river systems and coastal areas, and now we are talking about flooding. Those different aspects of water in the environment are to some extent linked together and there are things you can consider that will have an impact on all of those issues.
“I am concerned that with all of the other priorities that governments at different levels have to deal with, managing our water resources may not get the attention it deserves. The risk is that we continue to be somewhat reactive. We wait until there has been a flood event and then we try to stop that event from occurring again in the same place in the future. We need to think at slightly larger scale about how we can mitigate and also help people to adapt to climate change at a national scale.”
On why our engineering has resulted in floods:
“Traditionally, a lot of flood management has involved engineering structures to provide protection around critical infrastructure. That hard engineering approach works very effectively, but it is very expensive. Secondly, the hard engineering approach also has significant drawbacks as it leads to rivers becoming ecologically impoverished and detached from their natural floodplains.
“In parts of the world where hard engineering has been used at scale, for example in Japan, there is a movement now towards moving away from those hard structures towards a more holistic natural flood management approach to try to deal with the problem at the source.
“We’ve built houses, factories and roads on floodplains, so some of the natural route water would have taken to drain away might have drained into the floodplain soils. A lot of those are now covered over with hard surfaces means that some of the natural routes the water would have followed are now obstructed, and the water gets diverted. It ends up ponding up in certain areas and you get the sort of pictures that we have seen over the last few weeks.”
Dr Linda Speight, Departmental Lecturer School of Geography and the Environment at the University of Oxford, said:
Why the flooding has been so bad recently:
“This autumn/winter has been warm, wet and windy. The Met Office have named eight storms since the start of September (compare that to 2022/3 when there were only four named storms all year). These consecutive storms mean that the ground has not had time to dry out between events and rivers have been running high. More rain falling onto saturated ground has no where to go and causes floods.
“It is the widespread and persistent nature of the latest rainfall that has been the biggest problem. Larger river systems like the Severn and the Trent can carry a lot of water, but when it rains across the whole catchment water flows down all of the tributaries at the same time, causing large volumes of water to amass in the lower floodplains. This is what we are currently seeing in locations such as Gloucestershire.
Any links to climate change:
“Climate change is warming the atmosphere. A warmer atmosphere can hold more moisture meaning that when it rains the rainfall is heavier and more likely to lead to flooding. In particularly we know that climate change is leading to warmer and wetter winters in the UK. We will unfortunately experience more winters like this one in the future.
“Alongside the climate other changes such as increased building on floodplains, river management and changing landuse across the catchment can also increase flood risk. Hydrology is complicated meaning it is difficult to isolate the impact of any one of these factors. A combination of the changing climate and its interactions with the landscape is leading to more frequent floods across the UK.
How much our infrastructure is prepared for these floods and where the weak points are:
“Thanks to the excellent historic records that we have of rainfall, river flows and past flood events, combined with models and maps produced by hydrologists we know where floods are likely to occur. In locations where there are lots of properties or infrastructure at risk we use hard engineering solutions to protect from floods. Thousands of properties have been protected by flood defences this week (a good example can be seen at Upton on Severn from earlier this week). None the less it is distressing for households and farmers who’s land is not protected. The problem is we cannot build flood defences everywhere. It would be too expensive and in any case water has to go somewhere, floodplains provide an important function for storing water and slowing down flood peaks, disconnecting the river from its floodplain often leads to more problems downstream.
“As the climate changes floods will get bigger. Our flood defences are designed based on the past climate and the chance of floods that overtop the existing defences is increasing. Understanding the effects of climate change on river flows is important to ensure we can continue to protect critical infrastructure in the future. We also need to continue to improve societies resilience to floods for example by designing properties which are flood proof for example by moving living areas upstairs and raising plug sockets, and investing in flood forecasting, warning and response to reduce the impacts of floods.
“To help the UK be better prepared for floods, many hydrologists – including me – are working together through the new UK Flood Hydrology Roadmap. Published by the Environment Agency in 2022 it sets out a 25 year vision to ensure society has improved hydrological information and understanding to manage flood hazard in a changing world.”
Steve Turner, a hydrologist at the UK Centre for Ecology & Hydrology, said:
Why has the flooding been so bad recently?
“Since the autumn, we have seen quite unsettled weather patterns, meaning multiple low-pressure systems bringing wind and rain have left the ground saturated. Subsequent rainfall has nowhere to go and this leads to flooding.
“During December, some areas in central & northern England and eastern Scotland recorded rainfall more than 70% above average for the time of year. This has continued into January with Storm Henk – our eighth named storm of the season, which is already the highest number of storms affecting the UK to be named by January by the Met Office in a year since they started naming them in 2015.
“For the UK as a whole, the period between July and December 2023 was the wettest on record (in a series from 1890).”
Any links to climate change?
“There is growing scientific evidence of a connection between climate change and increased flooding which, in general terms, is because a warmer atmosphere can store more water, leading to more intense rainfall.
“There are have been significant increases in the severity of flooding in many parts of the UK over the past 50 years. Though it is still difficult to conclusively attribute these long-term trends in flooding to climate change and too early to speculate about a link to the current events.
“However, the role of human-induced warming has been demonstrated for various flood events. Studies involving UKCEH indicate the widespread flooding in the UK in 2013/2014 was made more likely by human-driven climate change. Other researchers made a similar link regarding the winter 2015/2016 floods.”
What to expect in the future?
“Future projections suggest the UK overall may experience wetter winters as well as summers that are hotter and drier than at present but with periods of more intense rainfall.
“Continued human-induced climate warming in future is likely to result in further increases in peak river flows, which will cause more severe flooding and impacts on people, property and public services.
“However, projections based on the latest climate and river flow modelling show the extent of future flooding will vary across the country.”
Prof Hannah Cloke, Professor of Hydrology at the University of Reading, said:
“For communities that have been affected, these floods are devastating and the families and businesses that are currently under water may take months or years to recover. It’s important that everyone recognises the dreadful impact that flooding can have on people’s lives.
“Scientifically speaking, this flood is interesting because the impact is so widespread across the UK at the same time. Every flood is unique, and flooding is common in the UK, but we usually see one small area affected very intensely while other areas nearby may escape relatively unscathed. This year there has been a widespread wet autumn and intense rainfall has affected different regions at the same time.
“As well as buildings and homes being flooded, this flood has affected a lot of infrastructure, causing disruption that when added up will cost our economy millions of pounds in lost productivity.
“As well as the widespread flooding impacting roads, railways and energy supplies, there has been an appalling cost to nature. Our sewers can’t cope very well even during normal rainfall, and with this extreme weather, we have seen a widespread release of sewage into our rivers and seas.
“In terms of the forecasts and warnings, this was unusual and will need careful investigation. Storm Henk was picked up and named quite late in weather forecasts as a potentially damaging storm. The first most people knew about it was when it got wet and windy, rather than hearing about the warning days ahead.
“I was sitting in my office watching the trees bash against my window before I knew that the Met Office had named the storm. In recent years, we have become used to getting much earlier warnings of such serious weather, which should allow people and official agencies to respond in advance. Flood early warning systems are complex and require all the parts of the chain to be working effectively. In this case, the warnings seem to have come too late to be useful for some people. I have heard of people who received official warnings of floods, hours after the water had already got into their homes and caused costly damage and trauma.
“We will need to look carefully at why some early warnings haven’t come in time to help people. Forecasting floods is a very difficult thing to do and requires the perfect co-ordination of weather forecasts, hydrological predictions, data from land, rivers and air, plus a chain of human activity, communication and action to work properly. We are getting better at it but when we get it wrong, people suffer. We need to remain humble in the face of nature and remember that we don’t have all the answers.”
Dr Kevin Collins, Senior Lecturer Environment & Systems at the Open University, said:
“Floods are not unusual in winter months in the UK. But the arrival of storms Babet, Ciarin, Debi, Elin, Fergus in close succession has meant river catchments were already full and the ground saturated before Storm Henk arrived. The intense rainfall has ‘no-where’ to go except to move rapidly into our rivers causing many to burst their banks.
“Climate change is making rainfall events more intense because warmer air can carry more moisture. Globally, in mountain areas and in higher latitudes, it is estimated that extreme rain is increased by 15% for every 1 degree of warming. However, the influence of climate change on the frequency of storms in the UK remains uncertain.
“In areas which have a longer history of flooding, such as towns and villages on the River Severn and River Thames there are well developed flood defences which can cope with ‘normal’ winter floods.
“However, much of our infrastructure has been designed in a previous century and is being overtaken by climate change.
“Weak spots include railways and roads which are unable to cope with flooding from intense rainfall events and increased urban runoff as we expand our towns and cities.
“Streets and communities which have never flooded are now at increased risk, especially where we have built on marginal land.
“Our farming systems are also at risk where agricultural land is increasingly used for flood relief for towns, but limits capacity for food production and threatens the economic viability of farming.
“Water supply and sewage systems in particular are unable to cope with the combination of intense rainfall and increased urban run-off as our population expands, we use more water per day and we continue to pave over gardens and build on green-field sites.
“Our electricity grid and network of substations have had increased protection following severe floods in the past, but still remain vulnerable to extreme weather.
“Looking ahead, the UK will experience more events we currently consider unprecedented or extreme – whether floods, heatwaves, droughts or storms. When it comes to planning and development of our infrastructure, we need to do less of what we’ve always done. We now need to be thinking about the systemic risks to our communities and economy and act to build resilience to these kinds of floods by accepting and adapting with the new normal of climate change.”
Will McBain, Associate Director for Adaptation and Resilience (Water) at Arup, said:
“The extended period of wet weather, and consequently high river flows, that have affected many parts of the UK since early October are undoubtedly testing the metal of the nation’s infrastructure. It is a reminder of the fact that hydraulic loading is not just a peak flow issue. Extended high flow periods are of particular concern regarding the stability of historic earthworks, bridges and river training walls. Lessons learnt from floods over the past decade have resulted in improved inspection regimes and better understanding of the failure mechanisms associated with such structures. A risk-based approach to asset management means that “high consequence” asset failures are relatively uncommon. But that does not make the experience of flooding any less horrific for those who are impacted.”
Dr Margaret Currie, a senior researcher at The James Hutton Institute, says:
“Our research at the Hutton has demonstrated that flooding affects people for years after the event and recommends ways in which flooded households and communities can be appropriately supported in the immediate aftermath as well as the longer-term.
“A key learning has been around having more localised flood warnings, to allow communities to prepare. As flooding becomes more variable and localised, this will be increasingly important. In Scotland, this is already being done, as was seen during Storm Babet, late last year. People are also now more aware that they can go online to check river water levels, which can give reassurance.”
Dr Emily Wallace, Met Office Fellow in Climate Extremes, said:
“Although observations show large variability in annual, seasonal, and decadal rainfall, there has been a marked increase in winter rainfall in the most recent decade with 2014, 2016 and 2020 all in the top five wettest (the other winters being 1995 and 1990).
“As the atmosphere warms due to human induced climate change it can hold more moisture, at a rate of around 7% more moisture for every degree of warming. On a simple level, this explains why in many regions of the world projections show an increase in precipitation as a consequence of human induced climate change.
“In the future, climate projections for the UK indicate there being a greater risk of heavy precipitation and prolonged events in the future, particularly during winter.”
Dr Christian Dunn, Chair of the British Ecological Society Welsh Policy Group and Reader at Bangor University, said:
“The recent flooding has highlighted the perfect storm we are facing in the UK, as the climate changes and the disastrous management of our landscapes takes effect.
“Nature provided us with an answer to prevent flooding – wetlands.
“These marshes, bogs and fens act as giant sponges – soaking up vast amounts of rain water during the wetter months and releasing it during drier periods.
“Since the 1700s though the UK has lost 75% of these vital water management habitats.
“We’ve dug up our peatlands, we’ve drained our marshes and we’ve built on our riparian buffers and flood plains.
“And now, with the changing weather patterns potentially increasing the likelihood of heavy rainfalls we have no natural protection from the effects of flooding.
“If we want to stop our villages, towns and cities from being underwater every time we have a storm, we need to manage and conserve our country’s existing wetlands and we need to create more of them.
“These so called Nature-based Solutions are at the frontline of our defense against flooding and we need to increase our protection of them at nothing short of war-level footing.”
Dr Jess Neumann, Associate Professor of Hydrology at the University of Reading, said:
“With the ground already saturated and rivers swollen from ongoing wet weather, communities should take steps now to adapt to flooding. Having an emergency preparedness plan and flood kit ready can help save lives and property.
“Specifically, people should check government websites and local media for the latest weather alerts and flood warnings. Make sure you know evacuation routes and shelter locations in case an order is given to leave the area.
“Gather supplies for an emergency flood kit – this should include drinking water, non-perishable food, flashlight, battery-powered radio, extra batteries, first aid kit, prescription medications, blanket, gloves, sturdy waterproof boots, water purification tablets, and personal hygiene items. Charge mobile phones and any battery-powered devices.
“Protect your home by moving valuable items and electronics to higher levels in your house. Clear debris from gutters. Review your insurance policy and coverage.
“If rising floodwaters threaten your home, make sure you know how to quickly shut off electricity, gas, and water supplies. Unplug small appliances beforehand. Have accessible items like sandbags, plywood, plastic sheeting, and lumber on hand to help prevent water entry.
“Check on elderly neighbours, those with mobility issues, and others who may need additional assistance preparing or evacuating in the event flooding occurs. Make sure they have a way to receive alerts and have their emergency kit ready to go.”
Prof Hannah Cloke, Professor of Hydrology at the University of Reading, said:
“The decorations have been taken down but the flood warning map of England is currently lit up like a Christmas tree.
“Storm after storm this autumn and winter has made Britain a sopping wet sponge and there is nowhere for any extra rain to go.
“After Storm Henk formed late in the Atlantic and hit us on January 2, all that extra water is running straight off the landscape and our rivers are swelling up like the beautiful monsters they can be.
“Forecasts suggest we will have some respite from the rain by the weekend. The sun may come out but the waters could still be rising, so everyone should be checking for flood alerts.
“People should be very careful not to drive or walk through flood water. It is extremely dangerous. Even if you see other people doing it, don’t follow them. You should stop and turn around. The water may look shallow there, but it doesn’t take much to float a car and you could easily be swept away.
“Unfortunately in these extreme conditions, and due to the creaky nature of our sewers, there will be raw sewage getting into the water everywhere. It is a reminder that we need to invest a lot more into our water system to deal with increasing risks of flooding in the years ahead, which we know is likely to get worse.
“Mild, warmer winters, heavier downpours of rain, and storms that hit us week after week are all examples of the impacts of climate change that are increasingly affecting the UK right now. This should be a reminder of the need to adapt our cities and infrastructure to deal with this hotter, more hazardous climate. It shows a small taste of the enormous costs we are building up in the years ahead if we fail to bring down emissions fast enough.”
Prof Rick Stafford, Chair of the British Ecological Society Policy Committee and Professor at Bournemouth University, said:
“While we are seeing an increased intensity of rainfall, as a result of climate change, we are also not utilising nature sufficiently to help mitigate the risk of floods. Nature-based solutions, such as restoring peatbogs and wetlands, or planting trees in some upland areas, can help regulate the flow of rainwater to rivers and prevent flood risks. Some of these measures can also boost biodiversity and help capture carbon from the atmosphere and can be a real win-win situation for people and nature.”
The UK Centre for Ecology and Hydrology (UKCEH) also provided the following information which you can quote from if you want:
Declared interests
Emily Wallace: No declarations of interest
Steve Turner: No interests to declare.
Hannah Cloke: I work with and advise the Met Office, ECMWF and Environment Agency.
No reply to our request for DOIs has been received.