One in three people globally live with threat of floods

More than 2.7 billion people live in vulnerable areas with the Middle East and South Asia most at risk, Moody’s research found

People ride on a boat in a flooded street near the river in western Poland.EPA

More than 2.7 billion people globally live in areas vulnerable to coastal or inland flooding, research by risk analysis group Moody’s has found.

The proportion of people exposed to flood risk has also steadily increased since 1975, driven in part by climate change and urbanisation, the research said. The Middle East and South Asia, researched together as one region, was found to be at most risk for floods.

The Moody’s RMS study was published as central Europe reels from floods that caused billions of dollars worth of damage and the US recovers from Hurricane Helene, which spread destruction far inland.

The report took current population numbers and looked at projections for 10, 30, 50 and 100 years. More than one third of the global population live in areas vulnerable to inland or coastal flooding, Moody’s said.

Of those, 2.3 billion people are at risk from more than 10cm of inland flooding according to the 100-year forecast, and 240 million from coastal flooding.

“Flooding is a pervasive and recurrent natural hazard that has far-reaching consequences for both human communities and the environment,” Moody’s said.

“As flooding continues to pose a growing threat, understanding the populations most vulnerable to its effects is paramount for effective disaster management and mitigation efforts.”

More than 70 per cent of the people exposed to coastal flooding risks over the next 100 years are in five countries – India, China, Pakistan, Bangladesh and Indonesia.

“South Asia stands out as the most flood-prone region, with almost 40 per cent of its inhabitants susceptible to inland flooding at the 100-year return period level.” Moody's said. “South Asia also tops the list when it comes to coastal flooding with just over five per cent of its population at risk at the same return period.”

In the 100-year forecast, 25 per cent of the global population exposed to inland floods will be protected by flood defences, and 36 per cent for coastal floods.

Hurricane Helene showed the risk of flooding from major storms hundreds of kilometres away from the point where they first strike land.

Hurricane Helene leaves path of destruction – in pictures

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  Soldiers arrive to help residents remove debris and mud from their homes after Hurricane Helene in Marshall, North Carolina. Reuters

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  Soldiers set up a camp near the town of Marshall as part of the response to the hurricane that affected much of North Carolina. Reuters

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  A resident walks through debris after Hurricane Helene, in Marshall, North Carolina. Reuters

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  A boat driven ashore by Hurricane Helene on Keaton Beach, Florida, on Friday September 27. More than 30 people were killed in Florida and other south-eastern US states when Helene struck. AFP

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  A rescue team takes residents to safety from flooding as Tropical Storm Helene strikes Boone, North Carolina, on Friday September 27. Reuters

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  Hurricane Helene toppled the forecourt roof of a petrol station in Perry, Florida, on Friday September 27, 2024. AFP

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  A resident of Boone, North Carolina, helps to free a car that became stranded in a stretch of flooded road. Reuters

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  Nash Harris and his mother Alicia hoping to salvage belongings after Hurricane Helene brought a tree down on their home in Steinhatchee, Florida. Reuters

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  The aftermath of Hurricane Helene in Horseshoe Beach, Florida, on Friday, September 27. Reuters

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  Waylon and Nash Harris at their home in Steinhatchee, Florida, in Helen's wake on September 27. Reuters

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  A tree pulled down electrical wires in Cedar Key, Florida. Reuters

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  Damage inflicted by Hurricane Helene on a home in Steinhatchee, Florida. Reuters

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  Residents assess flood damage in Boone, North Carolina, on September 27. Heavy rains caused severe flooding in many parts of the Blue Ridge Mountains. Getty Images / AFP

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  Flood waters destroy a bridge during Tropical Storm Helene in Boone, North Carolina, on Friday, September 27. Reuters

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  Torrential flooding inundated communities like Steinhatchee in Florida, and emergency responders launched rescue operations. AFP

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  Steinhatchee in Florida following Hurricane Helene on Friday September 27. Reuters

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  Power crews work on lines after Hurricane Helene passed Crystal River, Florida. Getty Images / AFP

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  At the seawall in the aftermath of Hurricane Helene at the Davis Islands' Seaplane Basin near Peter O Airport in Tampa, Florida, on September 27. AP Photo

Despite the storm coming ashore in Florida and travelling across all of Georgia – over land that slowed winds speeds – it still hit North Carolina with heavy rain and strong, but not hurricane strength, winds.

The storm dumped more than 35cm of rain over three days on to the western North Carolina, transforming mountainsides into mudslides and creeks into torrents.

Insured losses from floods in central Europe – areas of the Czech Republic, Austria, Poland, Slovakia, Hungary, Germany, and Italy – are could reach $3.9 billion, Moody's estimates. The widespread flooding was triggered by heavy and persistent rainfall which exceeded 40cm in places.