Historically, China relied on dams, levees, and reservoirs to regulate water flow. Authorities have warned a damaged dam could collapse at any time. China’s government is trying to reduce the impact of flooding on its rural areas. The country has introduced a “sponge city” programme which aims to stop water accumulating on the ground. But some rural areas have suffered severe damage to their homes, crops and livelihoods.
- China has touted its dam network as a solution to its devastating floods.
- Recent deluges have killed hundreds of people and flooded thousands of homes.
- Historically, China relied on dams, levees, and reservoirs to regulate water flow.
- Urban growth has resulted in an increase in impermeable concrete coverage, raising the risk of rapid water building on the surface during periods of heavy rain with insufficient drainage.
- The load on China’s dams is set to increase as climate change increases the frequency of extreme weather events, an expert believes.
- The floods “serve as a wake-up call to China that climate change has arrived,” according to Greenpeace East Asia.
- However, China is increasing flood surveillance and evacuating residents early to limit the human cost of flooding, an official said.
Central China has been overwhelmed by record rainfall, with floods damaging an underground metro system, dams and riverbanks, and resulting in landslides and building collapses.
Beijing has hailed its gigantic dam network as a panacea for the city’s destructive yearly floods, but recent deluges have killed hundreds of people and flooded thousands of homes.
Here are five questions about why China continues to experience severe flooding on a yearly basis.
Historically, China relied on dams, levees, and reservoirs to regulate water flow.
Around 30 billion cubic metres of floodwater were intercepted last year by dams and reservoirs on Asia’s largest river, the Yangtze, preventing flooding downstream in areas including Shanghai, according to China’s disaster management ministry.
However, the country’s massive water management systems are unable of containing all of the flooding, and there are concerns about the durability of dams constructed decades ago.
The army warned Tuesday night that a dilapidated dam in Henan province “may collapse at any time” following a record downpour. Troops blew a hole in the dam to discharge water and rushed to strengthen other embankments across the province using sandbags.
Authorities in eastern Anhui province were obliged to blow up two dams last year to allow water from the Chuhe River to flow across crops.
And concerns about the structural integrity of the Three Gorges Dam on the upper Yangtze, the world’s largest hydroelectric project, are resurrected on a regular basis. The dam was built in an area crisscrossed by geological faultlines.
The pressure on China’s dams is anticipated to increase as climate change increases the frequency of extreme weather occurrences.
As the Earth’s atmosphere warms, it retains more moisture, intensifying downpours, Benjamin Horton, director of Singapore’s Earth Observatory, told AFP.
According to China’s ministry of water resources, water levels reached unprecedented highs in 53 rivers last summer, as experts warned the Three Gorges Dam would face its worst flood peak since it began operation in 2003.
Meanwhile, officials in Zhengzhou, the epicenter of this week’s torrential downpours, said that the city received an average year’s worth of rain in just three days.
According to AFP, Li Shuo, a climate analyst with Greenpeace East Asia, the floods “serve as a wake-up call for China that climate change is here.”
Flooding has also been exacerbated by the country’s fast expansion and urbanisation.
Urban sprawl has covered an increasing amount of land with impermeable concrete, increasing the risk of rapid water building on the surface after heavy rains.
Horton also stated that the size of several of the country’s largest lakes had been severely diminished.
One of the government’s remedies has been a 2014-launched “sponge city” scheme.
It aims to replace impervious urban surfaces with porous materials, permeable pavements, increased green space, drainage areas, and reservoirs in order to prevent water from pooling on the ground.
“The goal is for stormwater to flow into drains or green spaces and have a minimal impact on constructed areas,” Cecilia Tortajada, a water policy researcher at the National University of Singapore, told AFP.
However, sponge cities will provide little comfort to rural people that have experienced catastrophic damage to their homes and crops as a result of diverted water.
“While urban residents in China’s megacities are generally unaffected by rising water, a big portion of the country’s hinterland along the Yangtze River has been thrust into the spotlight,” Li explained.
Entire villages are often permitted to flood while residents are evacuated to avoid highly crowded cities.
Rainwater has destroyed almost 20,000 hectares of crops in rural areas surrounding Zhengzhou in recent days, according to Xinhua, at a direct economic cost of more than $11 million.
China is also increasing flood surveillance and evacuating residents early to lessen the human cost of flooding.
Along with conventional weather monitoring technology, Anqing city in China’s Anhui province is reportedly deploying virtual reality goggles connected to river monitoring cameras that feed photos to inspectors through 5G internet.
The ministry of emergency reported last year that the number of individuals killed or missing as a result of summer flooding between June and August dropped to 219, less than half the average annual amount for the previous five years.
However, economic costs increased 15% to 179 billion Yuan ($26 billion).
Tortajada stated that flood control will ultimately necessitate worldwide effort to combat climate change.
“While individual countries are improving their preparedness, the world as a whole is not,” she told AFP.