Floods in Vietnam exacerbated by climate change and concrete construction

The location and topography of this Southeast Asian country make it naturally vulnerable to typhoons and floods, but the situation is worsening due to more violent rainfall caused by climate change and rampant urbanization.

More violent storms

Vietnam is one of the regions of the world most affected by cyclones, and is usually subject to heavy rains between June and September.

Around ten typhoons or tropical storms typically hit Vietnam each year. By 2025, that number had already reached twelve.

"Climate change is already influencing Vietnam's exposure" to storms, explains Nguyen Phuong Loan, a climatologist at the University of New South Wales in Australia.

Research suggests that climate change is likely to lead to "potentially more intense tropical cyclones (typhoons)," as well as more violent rainfall, because a warmer atmosphere retains more moisture.

"This implies a higher risk of flash floods, particularly in densely populated urban areas," according to Nguyen Phuong Loan.

Rising sea levels also put pressure on coastal regions.

Topography, infrastructure

With 3.200 kilometers of coastline and a network of some 2.300 rivers, Vietnam faces a high risk of flooding.

Most of the country, due to its topography and hydrology, has a low natural capacity to drain quickly after heavy flooding.

In some cases, the construction of buildings and infrastructure and environmental degradation have worsened the phenomenon, according to meteorology expert Nguyen Lan Oanh.

The destruction of upstream forests for hydroelectric projects, the concreting of drainage canals and rampant urbanization have "seriously contributed" to flooding and the increase in landslides, she told AFP.

"Humans must change their perception of how they treat nature in order for us to achieve a safer world."

Devastating consequences

This week alone, floods triggered by record rainfall in central Vietnam have killed at least 10 people and affected hundreds of thousands of homes. In the coastal city of Hue, up to 1,7 meters of rain fell in 24 hours.

These floods come after other floods, notably in Hanoi.

In total, climate disasters - storms, floods or landslides - have caused at least 187 deaths in Vietnam during the first nine months of the year.

Hundreds more people were killed or went missing last year, many due to Typhoon Yagi, the most powerful to hit the country in decades. It caused some $1,6 billion in losses to the economy.

Adaptation

Vietnam is "making significant efforts in terms of early warning," says Ralf Toumi of Imperial College London.

During recent floods, the government issued evacuation orders and helped residents take refuge in higher areas, he explains.

Dikes and drainage systems in the major deltas of the Red River and the Mekong have been reinforced, upgraded or simply installed.

But often, "attention is focused on infrastructure in the context of (natural) disasters when it should also focus" on not creating more risks, explains Brad Jessup, an expert at the University of Melbourne in Australia.

"Without risk reduction measures, the need for protective infrastructure continues to increase. It's a spiral."

Adapting to climate change is expensive, and rich countries have failed to keep their promise to fund it for developing countries like Vietnam.