Revealed: The 20 countries with the highest number of towns and cities at risk of deadly flooding – so, is your home at risk?
Scientists have revealed the 20 countries with the largest number of towns and cities prone to potentially deadly flooding due to climate change.
The researchers are concerned that settlements are expanding into flood hazard zones instead of moving away from them – threatening lives in the near future.
The Netherlands tops their list, followed by Vietnam, the Southeast Asian country of Laos, Bangladesh and Fiji in the South Pacific.
But also in the top 20 are Japan, China, Switzerland, Croatia, Austria, Egypt and South and North Korea.
Although Britain is not on the new list, previous research has shown that one in six English properties could be affected by flooding due to sea level rise by 2050.
Scientists have revealed the 20 countries with the largest number of settlements prone to potentially deadly flooding due to climate change
Scientists today issued a dire warning: stop building houses in flood hazard zones (areas prone to flooding due to climate change). Pictured: Aerial photo of the same location in Quảng Nam, Vietnam, in 2002 (left) and 2021 (right). Note the expansion of buildings, mostly homes, in flood-prone areas near the water
The new study was led by Jun Rentschler, an economist at the World Bank, the global financial institution based in Washington, DC.
Exposure to flooding was found to be particularly high in countries where settlements are concentrated along river valleys and watersheds (such as Bhutan, Egypt and Bangladesh) and coastal areas (such as Fiji and Vietnam) or both (such as the Netherlands).
“Since 1985, human settlements around the world – from villages to megacities – have expanded continuously and rapidly into modern-day food zones,” Rentschler and colleagues say in their study.
“In many regions, growth in the most dangerous food zones far exceeds growth in unexposed zones, especially in East Asia.
‘Rather than adjusting their exposure to climate hazards, many countries are actively increasing it.
Evidence is mounting that climate change is increasing the risk of ‘extreme natural shocks’ such as flooding, experts say.
Climate warming is caused by the release of gases such as CO2 and methane into the atmosphere, which trap heat (known as the greenhouse effect).
Global warming is already melting the ice in the polar regions, and this meltwater is entering the oceans, gradually causing sea level rise and severe flooding.
Warmer air can also hold more water, increasing rainfall on average around the world, increasing the threat of flooding, as recently seen in New York.
Scientists already think that the people most at risk of dying from rising sea levels are those living in coastal areas, which will be the first to be permanently submerged.
The Netherlands tops the list, followed by Vietnam, the North African country of Laos, Bangladesh and Fiji in the South Pacific
Scientists blame increased heavy rainfall due to climate change for recent flooding in the New York region (pictured). Warmer air can hold more water, so precipitation increases on average across the world, the Met Office said
READ MORE Big Apple recorded wettest day EVER
Flooding across the city prompted Mayor Eric Adams and Governor Kathy Hochui to declare a state of emergency, which remains in effect Friday evening.
For the study, the team combined global flood hazard data with annual ‘settlement footprint data’ – which shows where people live and work in towns and cities – from 1985 to 2015.
They found that the size of the world’s settlements increased by 85.4 percent over this thirty-year period.
But settlements with ‘high exposure to flood hazard’ – defined as areas at risk of flooding depths of more than 150cm during one-in-100-year floods – grew by a whopping 105.8 percent.
Meanwhile, the number of settlements exposed to the highest flood risk during the period rose by a worrying 121.6 percent.
Unfortunately, even in high-income countries such as the Netherlands, many settlements are not protected from such one-in-a-hundred-year floods.
The story is much worse in the low- and middle-income countries in the top 20, such as Laos and Vietnam, where financing to build such defenses is not available.
In Laos and Vietnam, for example, there are many ‘very vulnerable’ settlements without strong protection systems.
Although the Netherlands tops the list when it comes to settlements in danger zones, it is, along with Japan and the US, one of the few countries investing heavily in protecting settlements that were already in high-risk flood areas in 1985.
For example, Dutch authorities have built sea dikes – man-made structures designed to protect low-lying areas – to protect against storm surges.
While the total size of the world’s settlements has increased by 85.4 percent, settlements with high exposure to flood hazard have grown by 105.8 percent and those exposed to the highest level of flood hazard by 121.6 percent .
Pictured are new locks, part of a storm protection project, in a part of Middletown, New Jersey, that was hit hard by Superstorm Sandy in 2012
Images of citizens dealing with flooding are becoming the norm. Pictured: A flooded street in Lagos, Nigeria in September 2023
The researchers say their findings have “concrete implications for city planners and policymakers” around the world – and not just in the top 20 countries.
“In areas where exposure to flooding is already high, investments in disaster preparedness are crucial to limit losses,” they say.
‘In areas where exposure to flooding is still low but rapidly increasing, revision of land use and urbanization plans is urgent, along with updating risk-based building codes and infrastructure master plans.
‘Although land scarcity and geographical constraints may mean that settlement in flood zones cannot always be avoided, flood protection systems and disaster preparedness measures can still support resilient socio-economic development.’
The research was published today in the journal Nature.