More than 100,000 people evacuated from homes in southern China due to floods

Study finds land under almost half of China’s major cities, including Beijing, is experiencing moderate to severe subsidence due to groundwater withdrawal and the weight of buildings

At least four people have died and 10 are missing after days of heavy rain caused widespread flooding in the southern Chinese province of Guangdong. More than 100,000 people have been evacuated from their homes as rescue workers used lifeboats to bring people to safety.

The area around the Pearl River delta is a major manufacturing hub, and is one of the most densely populated parts of China. It has long been prone to flooding but this week has seen record levels of rainfall and the Bei River’s water levels reached a 50-year high on Monday.

Hundreds of rescue workers were deployed during the weekend to bring to safety people trapped in flooded villages after roads were cut off by landslides. Electricity, phone and internet services were restored throughout most of the affected area on Monday, but some schools remained closed.

China’s meteorological service said heavy rain would continue at least until Tuesday as other parts of the country including Beijing were hit by storms and rain on Monday evening. A number of cities in Guangdong province have already broken records for cumulative rainfall in April, with thunderstorms signalling the earliest start to the flood season since 1998.


More frequent extreme weather events in recent years have heightened fears in China about the risks posed by climate change, particularly in coastal areas. A new report by scientists from China and the United States warned that some of the biggest Chinese cities are sinking as flood levels rise.

The study found that the land under almost half of China’s major cities, including Beijing and Tianjin, was experiencing moderate to severe subsidence, affecting about a third of the country’s urban population. Within a century about a quarter of China’s coastal land will have sunk below sea level, putting hundreds of millions of people at greater risk of flooding.

The study, which was published in the journal Science last Friday, was conducted by researchers from Chinese universities including South China Normal University and Peking University, and the Chinese Academy of Sciences, and from two universities in the US.

They suggested that the withdrawal of groundwater and the weight of buildings constructed during China’s rapid urbanisation in recent decades were among the factors causing subsidence.

“The subsidence appears to be associated with a range of factors such as groundwater withdrawal and the weight of buildings,” they wrote. “High-rise buildings are sprouting up, road systems are expanding, and groundwater is being used, all at a rapid pace.”

They warned that there was greater risk of coastal inundation unless adequate protective measures are implemented and maintained, pointing out that Shanghai, China’s most populous city, had taken the right steps.

“Shanghai and its neighbouring areas have been actively pursuing long-term control of groundwater extraction, which likely explains the slow subsidence observed there,” they wrote.

Robert Nicholls, a professor of climate adaptation at the University of East Anglia, pointed to Tokyo as an example of a city that had stopped subsidence in the late 20th century by protecting groundwater.

“Subsidence jeopardises the structural integrity of buildings and critical infrastructure and exacerbates the impacts of climate change in terms of flooding, particularly in coastal cities where it reinforces sea-level rise,” he said.

Denis Staunton

Denis Staunton

Denis Staunton is China Correspondent of The Irish Times