BEIJING • Weeks of torrential rain in southern China have left millions of people without homes and caused billions of yuan in losses, with environmental groups warning that the extreme floods are likely to become more common.

By late last month, more than 12 million people across 13 provinces had been affected, according to China's Ministry of Emergency Management.

The floods have killed 78 people, damaged 97,000 homes and caused 25 billion yuan (S$4.9 billion) in economic losses, it said.

Videos showed houses collapsing, cars afloat and crops dying in muddy, flooded fields.

Some cities also suffered infrastructure damage. In Yangshuo, an arch bridge was almost completely underwater while roads and a railway track in Chongqing near the Qi River were submerged.

China has struggled to contain flooding in its low-lying plains for millennia and uses dikes, dams and other features to manage the surges in water levels. But more unpredictable weather has made the task harder, endangering the lives of millions who live along the rivers.

"The devastating floods that we have seen are consistent with an increase in extreme weather events due to climate change," said Dr Liu Junyan, a Greenpeace East Asia campaigner.

"There is an urgent need to strengthen early warning systems for extreme weather events, to assess future climate risks in cities and to improve flood management systems."

The frequency of both extreme precipitation and high temperature events driven by climate change has risen steadily over the past six decades, according to a report published by China Meteorological Administration last year.

There have been five rounds of heavy rainfall in China's southern provinces since early last month, prompting the National Meteorological Centre to issue severe rainstorm alerts for almost every day of the month.

According to the agency, there will be two more rounds of heavy rain in the coming days.

BLOOMBERG