floods news, articles and features | New Scientist /topic/floods/ Science news and science articles from New Scientist Fri, 23 May 2025 15:17:53 +0000 en-US hourly 1 https://wordpress.org/?v=7.0.1 242057827 Flash floods sweep through vital sanctuary for Australian animals /article/2481536-flash-floods-sweep-through-vital-sanctuary-for-australian-animals/?utm_campaign=RSS|NSNS&utm_content=floods&utm_medium=RSS&utm_source=NSNS Fri, 23 May 2025 09:46:07 +0000 /?post_type=article&p=2481536
A Tasmanian devil is carried to safety by a ranger amid flooding at the Aussie Ark sanctuary
Aussie Ark

Conservation workers are racing to protect a precious group of Australian animals after record rainfall in New South Wales led to floods that have killed four people.

Tasmanian devils (Sarcophilus harrisii), brush-tailed rock wallabies (Petrogale penicillata), eastern quolls (Dasyurus viverrinus), long-nosed potoroos (Potorous tridactylus) and broad-toothed rats (Mastacomys fuscus) are all kept fenced safely away from feral predators such as cats and foxes at the 400-hectare Aussie Ark sanctuary in Barrington Tops, New South Wales. The sanctuary’s animals are considered an insurance policy for their species, in case wild populations become extinct.

Read more

Endangered skates saved from extinction by hatching in captivity

Since 2010, 500 devil joeys alone have been born there and around 50 of these have been released into a specially protected wild area. In coming years, some of these animals are expected to be released outside the sanctuary to re-establish Tasmanian devil populations on mainland Australia.

But this week, a severe low-pressure weather system has hit parts of New South Wales, leading to record-breaking storms. In just a few days, well over 400 millimetres of rain fell at the sanctuary. Even though it is at the top of a mountain at an altitude of 1200 metres, the park experienced flash flooding, sweeping away fencing that excludes feral animals and threatening to drown some of the breeding animals in smaller enclosures.

says many of the animals in the breeding enclosures have had to be brought into a makeshift emergency centre at the complex’s vet clinic. But the bigger problem facing the sanctuary is that around a kilometre of the 10-kilometre perimeter fence has been damaged or, in some locations, totally swept away by floodwaters.

“We’ve got about a kilometre of the fence that’s impacted from corner posts down, sections washed away and pushed over and strainer wires damaged,” says Faulkner. “The electrified hot wire is completely down, so we’re lucky we don’t have any Tyrannosaurus rex testing our defences.”

New South Wales NSW Wildlife floods.
A fence swept over by flooding at the Aussie Ark sanctuary
Aussie Ark

While the fences are damaged, Faulkner’s team has been camped out around the clock, keeping watch at breached sections. So far, no native species are thought to have escaped and no feral animals have entered.

“There’s water seeping, squeezing, pushing, running, pouring, flooding from every single little crack up here on the mountain, and I hate to think of all the wildlife that has also been devastated by these massive floods outside the sanctuary,” says Faulkner.

]]> 2481536 Google AI predicts floods four days early in South America and Africa /article/2387547-google-ai-predicts-floods-four-days-early-in-south-america-and-africa/?utm_campaign=RSS|NSNS&utm_content=floods&utm_medium=RSS&utm_source=NSNS Mon, 21 Aug 2023 07:00:50 +0000 /?post_type=article&p=2387547 2387547 How a UK river serves as a natural lab for flood defence research /article/2374110-how-a-uk-river-serves-as-a-natural-lab-for-flood-defence-research/?utm_campaign=RSS|NSNS&utm_content=floods&utm_medium=RSS&utm_source=NSNS Sat, 27 May 2023 13:00:27 +0000 /?post_type=article&p=2374110
Lake Wood is part of Eddleston Water, a stretch of river near Peebles, UK
Colin McLean
When I visit a research lab, I don’t normally expect to have to dodge sheep or get my shoes muddy, but this lab is far from normal. I am walking on farmland, about 30 kilometres outside of Edinburgh, UK. The air is crisp and I can hear a river babbling as I approach. It is this stretch of river, known as Eddleston Water, that I have come to see, guided by at the University of Dundee, UK. Working with the local environmental charity Tweed Forum, Spray and his team started studying the river in 2009 and it has been home to a series of real-world experiments ever since. They call it a “natural lab” for river science. Save Britain's rivers As we watch a dipper soaring in and out of the river in search of prey, Spray tells me that the lab was originally set up to cut the flood risk facing Peebles, a town of 9000 people, that sits on Eddleston Water. Spray and his colleagues wanted to find out how they could cut flood risk using nature-based solutions, such as tree planting, rather than building artificial dams. More importantly, they also wanted to find out how effective these methods really were. “Models are great and all, but it’s only with real-world data that you get a full understanding of all the various factors that can affect these results,” says Spray. Such methods, also known as natural flood management (NFM), are gaining traction: the UK government plans to in England using NFM from 60 to 120. But, despite this, the evidence base for NFM is relatively sparse, says Spray. One big question in hydrology is what happens when you make a river bendier, otherwise known as re-meandering. Many of the UK’s rivers were made artificially straight, freeing up room for roads and railways, but we now know this also increases the risk of floods. The idea goes that re-meandering rivers allows them to hold a greater volume of water and so avoid flooding. Yet Spray’s team has found that, at least in Eddleston Water, re-meandering alone doesn’t appear to have a major effect on flood risk. This is because the floodplain surrounding the newly bendy river isn’t particularly large, so can’t effectively store the water that overflows due to excess rain. But that doesn’t mean there aren’t benefits: a bendier river has a massive benefit for ecological diversity, says Spray. For example, the team found an increase in the number of spawning habitats for salmon in re-meandered sections of the river. This is one of the reasons why the dipper is trying its luck in the river today, says Spray.
Read more

Inside the fight for Europe’s first wild river national park
A closer look at the river also reveals the various ways in which the water seems to flow – it is far faster on the bendier bits, which contain more oxygen and can give rise to a greater variety of insect life. These parts of the river simply seem more alive than the unrestored sections. The researchers have also studied leaky dams, which are simply tree logs placed across a stream. During normal river flow, the water passes under the logs, but when river levels rise the dams cumulatively slow the flow of water. Spray shows me one of these dams, comprised of a dozen logs lying across a stretch of the river. It looks messy, more like debris than something placed by humans, but Spray says these haphazard logs have probably had the biggest impact on flooding in Peebles of all the interventions they have trialled. “You wouldn’t think it looking at them, but they’re such an easy and straightforward solution to cutting flood risk.” Beyond looking at flood risk, the team has quantified the monetary gains of its interventions. “Money talks,” says Spray. The researchers say that NFM has helped avoid £950,000 worth of flood damages in the 10 years since the first interventions were installed in 2012. But this is far outweighed by the ecological benefits to the region, such as improved carbon storage and increased water quality, which the team values at around £4.2 million. “This is what natural flood management can do that simply building flood defences cannot,” says Spray. But natural labs come with their own problems. Spray says the lab’s experiments are often a compromise with the dozens of landowners in the area, rather than perfect science. Re-meandering takes a lot of space and farmers may have other plans for that land, says Spray, so the team’s efforts have been scaled down from the ideal. “If the landowner doesn’t want it to happen, it doesn’t happen,” he says. “We don’t push our luck.”
Read more

New way to predict river flood risk could help prepare for disasters
That also points to a bigger problem with NFM. For it to work across the UK, river practitioners need to foster closer relationships with landowners, says Spray. But that is easier said than done and takes time. “We’ve been here for over a decade,” he says. “The trust has been hard fought for.” One solution is to pay landowners to use NFM, something the UK government is planning to do as part of its post-Brexit farming reforms, although the details haven’t yet been published. Spray hopes this will help increase the take-up of his team’s research. “But these techniques only work if you get farmers on board – you need to make it worth their while,” he says.]]> 2374110 New way to predict river flood risk could help prepare for disasters /article/2367089-new-way-to-predict-river-flood-risk-could-help-prepare-for-disasters/?utm_campaign=RSS|NSNS&utm_content=floods&utm_medium=RSS&utm_source=NSNS Thu, 30 Mar 2023 15:00:41 +0000 /?post_type=article&p=2367089
Severe flooding on the Ahr river in Germany in 2021
dpa picture alliance / Alamy Stock Photo

We may now be able to better predict which rivers are at risk of extreme flooding, even if they haven’t caused severe floods before.

Extreme flooding, such as the devastating  is difficult to predict, says at the Norwegian Institute for Water Research in Oslo. Typically, researchers only know a river is prone to extreme floods if this has happened in the past. “For this method to work, you have to wait for something bad to happen,” says Basso.

To look for other ways to predict extreme flood risk, Basso and his colleagues analysed discharge and flooding data from 101 rivers in Germany and the US going back at least 30 years.

They split the floods into two groups: those that were small in magnitude and expected for that river, and those that were extreme. The second group consisted of floods that were between 20 and 35 times bigger than a normal flood for a particular river.

The researchers studied the properties of the rivers that had experienced these extreme floods, including factors such as magnitude and frequency of rainfall and how quickly water appeared to flow from the surrounding regions to the river.

From this analysis, the researchers came up with two parameters that appeared to explain whether a river was likely to cause extreme flooding or not: how the area draining to the river (known as the river basin) retains and releases water, and the balance between how much rain the river receives and how much water evaporates from the region.

Basso and his colleagues then analysed data going back at least 10 years from 2519 rivers in Germany and the US, using these two parameters to determine whether a river was likely to cause extreme flooding or not.

They identified several rivers in Germany and the US that haven’t had extreme floods, but are thought to be at risk of them. In Germany, they include the Rems river in Baden-Württemberg and the Wörnitz and Vils rivers in Bavaria. In the US, rivers at risk of extreme flooding include the Baron Fork of the Illinois river and the Cowpasture river in Virginia. The team is currently using its model to predict which rivers are at risk of extreme flooding in the UK.

Read more

UK faces rising costs for flood damage even with modest warming

Being able to predict extreme floods is important, says Basso, because it is these floods in urban areas that officials are often unprepared for and cause the most damage.

“Hydrologists have known for some time that the most catastrophic floods are generated by different physical processes than smaller ‘normal’ floods, but the beauty of this study is that, for the first time, it identifies the places that are more likely to experience these disasters,” says at the University of Bristol, UK.

Journal reference:

Nature Geoscience

]]> 2367089 UK faces rising costs for flood damage even with modest warming /article/2363025-uk-faces-rising-costs-for-flood-damage-even-with-modest-warming/?utm_campaign=RSS|NSNS&utm_content=floods&utm_medium=RSS&utm_source=NSNS Tue, 07 Mar 2023 00:01:58 +0000 /?post_type=article&p=2363025
A flood in Somerset, UK, in January 2023
Matt Cardy/Getty Images
The amount of damage caused by floods each year in some parts of the UK will rise by 25 per cent even in the best-case climate scenario, according to a modelling study. and at the University of Bristol, UK, and their colleagues built a climate model that simulates water flow over land surfaces and used it to estimate how much flooding the UK would experience until 2070 based on various global temperature rises. They estimated the potential cost of flood damage based on insurance data on property values in areas that are currently at risk of flooding and those that may be at risk in the future. “It’s unfortunate that quantifying impact often needs to be in pounds and dollars,” says Wing. “Flooding can mean severe mental health implications, but it is harder to estimate these effects.” The team estimates that floods currently cause £740 million of damage each year in the UK, and this has increased by 1.4 per cent since 1990. The world is currently on track for the average temperature to reach 2.5°C above preindustrial levels by the end of the century. However, if countries achieve promised emissions reductions on time and global temperatures only rise to 1.8°C above preindustrial levels, the researchers found that the annual average amount of UK flood damage would only rise by 4 per cent compared with 1990 levels. “It’s quite a modest increase,” says Bates. But this figure disguises the fact that some parts of the country will face far worse flooding than others, he says. For example, parts of south-west Wales will face a 25 per cent rise in flood damage even in the best temperature rise scenario, says Bates. But if the promised reductions aren’t met, higher global temperatures will lead to more flood damage in the UK, the team found. With 2.5°C of warming, the annual average flood damage in the UK is predicted to increase by 13 per cent. If global temperatures go up by 3.3°C, it would rise by 23 per cent.
Read more

15 million people live in possible flood path for melting glaciers
Rising temperatures also mean that extreme flood years are likely to be more extreme and see more damage. At 3.3°C of warming, such years would be 40 per cent more damaging than those that are currently considered to be once-in-a-century events. The parts of the country that face the greatest risk of flood damage in the future are those that face the greatest risk today, says Bates. These include the south-east of England, north-west England, south Wales and central Scotland, he says. Bates says the research should compel the UK to take a leadership role in ensuring that countries don’t renege on their climate pledges. “We need to make sure the COP26 and net-zero pledges that different countries have signed up to are actually implemented,” he says. “This is an impressive study using the best models that are available to the insurance industry, which have been carefully validated against observed floods,” says at the University of Oxford. “Flood risk in the UK is set to increase because of the impacts of climate change that have already been ‘locked in’ with carbon emissions that are now in the atmosphere. If we do not mitigate carbon emissions vigorously, the situation is set to get worse this century,” he says.
Journal reference:

Natural Hazards and Earth System Sciences

]]> 2363025 Efforts to prevent the Yellow River flooding may have made it worse /article/2360988-efforts-to-prevent-the-yellow-river-flooding-may-have-made-it-worse/?utm_campaign=RSS|NSNS&utm_content=floods&utm_medium=RSS&utm_source=NSNS Thu, 23 Feb 2023 13:02:03 +0000 /?post_type=article&p=2360988
Satellite photo of the Yellow River delta in China
Satellite photo of the Yellow River delta in China
LWM/NASA/LANDSAT/Alamy

Building mud barriers alongside rivers to prevent floods may have the opposite effect, suggests an analysis of flooding from the Yellow River in China.

More extreme and frequent rainfall due to global warming means river flooding is a growing threat to millions of people worldwide. While there is a large body of research on how climate change affects flood risk, the role of human activities is less clear.

To explore this, at Jiangsu Normal University in China and his colleagues analysed the frequency of floods on the Yellow River in northern China. This 800-kilometre-long waterway was the cradle of ancient Chinese civilisation between 4100 and 3600 years ago.

The researchers compiled a timeline of floods on the river from the past 12,000 years using historical records and data from river sediments. They found that flooding was rare between 12,000 and 7000 years ago, with an average of just four floods every 100 years.

They then compared the timeline of floods with records of human activities, such as agriculture, and found that floods became more common following the expansion of local human settlements around 4000 years ago.

In particular, the analysis revealed that flooding rates substantially increased around 1500 years ago, when people began building mud ridges along the river as flood barriers called levees, says Yu.

Flooding occurred 10 times more often in the past 1000 years compared with before the start of ancient Chinese civilisation, the researchers found. Their analysis suggests that human activities, primarily the use of artificial embankments, drove about 80 per cent of this increase in flood rates, with the rest attributable to natural changes in the climate, says Yu.

Computational modelling of the river indicates that riverside mud barriers may lead to a greater build-up of sediment at the bottom of the river. This lifts the riverbed and raises water levels, making floods more likely, says Yu.

Read more

Why rivers are important for everything from biodiversity to wellbeing

“The work stresses the need to examine the range of human activities affecting flooding in the backdrop of climate change. This is an important message we must take on board today,” says at the University of Illinois Urbana-Champaign.

Artificial embankments are no longer used to stem flooding in the Yellow River. Since the early 1980s, the Chinese government has introduced a policy to conserve wild riverside vegetation, which keeps the soil around the river stable, says Yu. This helps prevent soil from falling in and may be a better approach, he says.

But as building mud barriers is still the preferred flood prevention strategy in many parts of the world, the research suggests that other countries should also shift away from artificial embankments, says Yu. “We can learn lessons from studying the history of rivers,” he says.

Science Advances

]]> 2360988 Australia’s Japanese encephalitis outbreak blamed on climate change /article/2312539-australias-japanese-encephalitis-outbreak-blamed-on-climate-change/?utm_campaign=RSS|NSNS&utm_content=floods&utm_medium=RSS&utm_source=NSNS Wed, 16 Mar 2022 14:00:03 +0000 /?post_type=article&p=2312539 A Culex mosquito, the genre of insect that can spread Japanese encephalitis
A Culex mosquito, the genus that can spread Japanese encephalitis
Konstantin Nechaev / Alamy
Australia is grappling with its first major outbreak of Japanese encephalitis, a viral disease that has already killed two people. The mosquito-transmitted infection is typically found in rural regions of Asia, but climate change is thought to have driven it further south – and other diseases could follow suit. Nineteen people have tested positive for the infection across four Australian states: Victoria, New South Wales, South Australia and Queensland. A man in his 60s from Victoria and another man in his 70s from New South Wales have died from the virus. The outbreak has taken many experts by surprise. “Japanese encephalitis virus was completely off the radar for us,” says  at the University of Queensland in Brisbane. The virus is transmitted via Culex mosquitoes that have previously bitten an infected animal, such as a pig or waterbird. Experts believe the infection may have entered Australia after recent floods along the east coast created additional wetlands. These may have attracted migratory waterbirds from Asia, carrying the virus over. “We know these birds often follow flooded watercourses,” says Hall. Local mosquitoes may have bitten these birds as they travelled along the waterways. Australia’s mosquito population is due to its recent warm, wet weather assisting the insects’ breeding. Once mosquitoes are infected, they can pass the virus to dense populations of pigs in commercial farms, causing an “amplifying effect”, says Hall. Mosquitoes that bite infected pigs can spread the virus to people who work with or live near the animals. Japanese encephalitis cannot spread from person to person. The virus has already been detected in pigs at more than 20 Australian farms, with some fearing the infection could spread to the country’s millions of feral pigs. “These pigs move over very wide ranges,” says  at QIMR Berghofer Medical Research Institute in Brisbane. Record-breaking rainfall, flooding and warm temperatures may have created a “perfect storm” that allowed the Japanese encephalitis virus to gain a foothold in Australia, with climate change potentially being to blame, says  at Monash University in Melbourne.

Read more: Brain disease takes a thousand lives in India

“We’re seeing changes in rainfall and temperature that are affecting the behaviours of the birds that host the virus, as well as increased breeding of the mosquitoes that spread it,” she says. The Japanese encephalitis virus has previously been detected in a handful of people in Australia’s Torres Strait Islands, north of the mainland. The ongoing outbreak is a first for mainland Australia. The vast majority of people who become infected . The virus spreads to the brain in about 1 in 250 cases, causing complications like seizures, tremors and paralysis. Up to 1 in 3 people who develop these severe symptoms die as a result of the infection. In Asia and Western Pacific regions, an estimated . Children are most likely to be affected. There is no cure, but administering fluids and oxygen can support the body while it fights off the virus. Vaccines can ward off infection. However, Australia only has 15,000 doses in its stockpile. The government says it is importing another , which will be . Vaccines will initially be , like piggery workers and veterinarians. “When we know more about the magnitude of risk in various geographic areas, we’ll be able to make informed decisions about who else should be vaccinated,” says Leder. In the meantime, people who live in mosquito-dense areas should wear long-sleeved clothing, apply mosquito repellent and remove stagnant water from around their house, she says. Now the Japanese encephalitis virus has been found animal hosts in Australia, it is “here to stay”, says Devine. “Sometimes it will be unseen and sometimes it will spill over [into humans], but it’s not going to disappear,” he says. Climate change is also expected to increase the prevalence of other mosquito-borne diseases in Australia, says Devine. For example, dengue-carrying mosquitoes that reside in northern Australia could migrate south as it gets warmer, he says. Australia should be better prepared for a rise in mosquito-transmitted viruses by ensuring appropriate tests are ready and building the capacity to make vaccines locally, says Hall. “We’re going to see more mosquito-borne diseases,” he says. “Exactly where, exactly when, we don’t know, but it will happen.”]]> 2312539 Record flooding in Australia driven by La Niña and climate change /article/2309783-record-flooding-in-australia-driven-by-la-nina-and-climate-change/?utm_campaign=RSS|NSNS&utm_content=floods&utm_medium=RSS&utm_source=NSNS Mon, 28 Feb 2022 10:42:00 +0000 /?post_type=article&p=2309783
TOPSHOT - A man paddles his kayak next to a submerged bus on a flooded street in the town of Milton in suburban Brisbane on February 28, 2022. (Photo by Patrick HAMILTON / AFP) (Photo by PATRICK HAMILTON/AFP /AFP via Getty Images)
A flooded street in Milton, a suburb of Brisbane
PATRICK HAMILTON/AFP/AFP via Getty Images

Record-breaking rain on the east coast of Australia over the past week has caused severe flooding that has claimed eight lives and damaged thousands of properties. The same region was hit by devastating floods last year and wildfires the year before, suggesting that predictions of more extreme weather due to climate change are coming true.

The city of Brisbane in Queensland is one of the worst-affected areas, having been pounded by a of rain in the week up to 28 February. In comparison, London records 690 millimetres in an average year.

“This rain bomb is just really, you know, it’s unrelenting… It’s just coming down in buckets,” state premier Annastacia Palaszczuk told media on 27 February.

About 18,000 homes in Brisbane and surrounding areas have been flooded and more than 50,000 are without power.

Queensland Fire and Emergency Services said on 27 February it was receiving . An emergency services officer whose vehicle was swept away on the way to rescue a trapped family was among those who have lost their lives. Many others are missing.

The deluge is now edging south into northern New South Wales. The city of Lismore is experiencing its worst flooding ever after its river rose to on 28 February, 2 metres higher than its previous record from 1954.

Videos from Lismore posted on social media show homes and shops underwater and people waiting to be rescued from their roofs.

The intense rainfall is due to a very slow-moving low-pressure system dragging moist air from the Coral Sea onto the east coast, says at the University of New South Wales in Sydney. “Because it’s so slow-moving – it’s basically stationary – it’s dumping all the water that it has on the same area,” she says.

The east coast was already experiencing more rainfall than usual due to La Niña, a weather cycle that brings wetter conditions every few years, says Ridder. “And now on top of that there’s the additional moisture from the Coral Sea,” she says.

Climate change is probably also a factor because as the atmosphere gets warmer, it can hold more moisture, says Ridder. “For each degree that the atmosphere is warmed, it can hold 7 per cent more water and that’s 7 per cent more water that can fall to the surface,” she says.

“We know that because of climate change, we’re seeing more rainfall come in the form of intense and heavy downpours,” says at the Climate Council of Australia, an independent advocacy organisation.

The east coast also experienced severe flooding in March last year, which was described by then-New South Wales premier Gladys Berejiklian as a “”.

The year before that, the east coast suffered its worst wildfires on record.

These extreme events are in line with predictions made in a . It said that climate change would result in “longer dry spells broken by heavier rainfall events” in Australia, meaning more wildfires and floods.

However, Australia has done little to address these threats and in global rankings of climate change action.

“The last few years really have brought home the brute reality of climate change in Australia,” says Bradshaw. “The threats are no longer in the future – they’re unfolding right here, right now with very serious consequences.”

]]> 2309783 Extreme rising seas could wipe out assets worth $14 trillion by 2100 /article/2250270-extreme-rising-seas-could-wipe-out-assets-worth-14-trillion-by-2100/?utm_campaign=RSS|NSNS&utm_content=floods&utm_medium=RSS&utm_source=NSNS Thu, 30 Jul 2020 15:00:02 +0000 /?post_type=article&p=2250270 Man caught by flood
Flooding in Carnlough in Northern Ireland on 20 December 2015
PAUL FAITH/AFP via Getty Images
Coastal floods wrought by rising seas could affect tens of millions more people and cause trillions of dollars of harm by the end of the century if the world fails to prevent the worst-case climate change scenario, according to a new analysis. The area of land globally at risk from coastal flooding could increase by almost half by 2100 as sea level rises put more homes, roads and other infrastructure in the firing line. Asia and north-west Europe are anticipated to be hit hardest. However, this worst-case scenario assumes humanity pumps out high levels of carbon dioxide, implements no flood defences and takes no adaptation measures. In a less dire scenario, where global CO2 emissions peak within two decades, the area at risk of flooding increases by only a third. Global finances take a smaller hit too, with up to $12.7 trillion of assets exposed rather than up to $14.2 trillion. The costs were calculated using populations affected and GDP figures. “The global cost of flooding is increasing by 2100, regardless of the emissions scenarios. Adaptation is really the only way out,” says Ebru Kirezci at the University of Melbourne, Australia, who led the analysis. She says adaptation could include building sea walls, early warning systems for communities and relocating populations to safer areas, which one study said last year is inevitable. The analysis calculated future sea level rise at nearly 10,000 points on coastlines. The team then modelled the impact of future flooding on land area, population and assets in two different climate scenarios. Benjamin Strauss at the US non-profit Climate Central says the researchers admit they have made assumptions that would tend to overestimate the threat. They deliberately didn’t consider any existing or future defences or adaptations, partly because they wanted to show all areas potentially at risk and due to difficulty accessing data for defences globally. They didn’t account for future changes in population or GDP either. However, Strauss says the study also underestimates the risk, as it based on a data that probably overstates coastal elevations by around 2 metres on average. His research, published last year, used a new method to estimate more accurate elevations. His study found 630 million people at risk of coastal flooding by 2100, far higher than the worst case 176 to 287 million projected by Kirezci and colleagues.

Scientific Reports

Sign up to our free Fix the Planet newsletter to get a monthly dose of climate optimism delivered straight to your inbox ]]> 2250270 Recent decades of European floods are among the worst in 500 years /article/2249489-recent-decades-of-european-floods-are-among-the-worst-in-500-years/?utm_campaign=RSS|NSNS&utm_content=floods&utm_medium=RSS&utm_source=NSNS Wed, 22 Jul 2020 15:00:40 +0000 /?post_type=article&p=2249489
German floods
Floods in Grimma, Germany, on 3 June 2013
JENS WOLF/DPA/AFP via Getty Images

The years 1990-2016 rank among the worst periods of flooding in Europe in five centuries, according to an assessment of historical letters, annals and legal records.

The period has seen intense floods such as those in England in 2009 and 2002’s devastating flooding in Dresden in Germany, Prague in the Czech Republic and across central Europe. However, a lack of detailed data beyond the past 50 years has left it unclear whether we are living through a particularly flood-rich period.

Günter Blöschl at the Vienna University of Technology in Austria says we are. Over seven years, his team built an unparalleled database of 103 rivers across Europe by scouring chronicles and other written records. Legal records proved reliable sources, including those from annual “beating the bounds” in England and Wales, where a church leader walked around a parish to record boundaries and often noted floods.

Read more: Climate change will boost risk of extreme flooding in northern Europe

“We’ve almost exclusively used original sources. Second-hand information is much more accessible but it’s also less accurate,” says Blöschl. The descriptions were used to class 9576 floods as notable, great or extraordinary, in order to measure flood-rich periods – when floods were bigger in extent and frequency than average – since 1500.

The database revealed that 1990 to 2016 was the third most flood-rich period, behind 1840 to 1880 and 1750 to 1800, which was at number one. Blöschl says each one could move up or down a position in the rankings if the analysis was tweaked, due to patchier records in some years and places. Data is relatively scant for Scandinavia, for example, and the team ended their analysis at 2016.

The most recent period is markedly different to older ones. Most of the past flood-rich periods were associated with cooler temperatures, but the current one comes amid a backdrop of climate change-driven warmth. Blöschl believes storms shifting northwards are to blame. More of the recent floods have also been in summer than past flood spells – 55 per cent versus 41 to 42 per cent – driven largely by more summer floods in central Europe.

According to the team’s analysis, the period 1900 to 1990 was relatively disaster-free, which is why the recent floods have taken many people by surprise. “People forgot the extent and frequency of floods that may occur,” says Blöschl. “They had a false sense of security.”

Nature

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