Reference News Network reported on August 19 that Deutsche Welle radio published a report on August 13 entitled "Can Mega Floods Be Prevented?" The full excerpt of the article is as follows:
Torrential rains triggered by Typhoon Du Suri recently hit the Chinese capital Beijing and surrounding areas, while huge flooding also occurred in northeast China. In Slovenia in Central Europe, two-thirds of the country is battling floods, landslides and dam bursts caused by torrential rains. At the same time, severe weather also hit Austria, Poland, Croatia and Slovakia.
That's not the only country hit by deadly storms this summer. In early July, unprecedented rains in the United States, India, the United Kingdom and Spain triggered flash floods that caused loss of life and damaged infrastructure.
When "incredibly terrible flash floods" occurred in Spain, American meteorologist and climate journalist Eric Holthouse tweeted: "Warmer air can carry more water vapor. Record high temperatures brought record rainfall, triggering record flooding. ”
Building Flood Protection: Climate Adaptation Strategies
From Germany to Pakistan, record floods have been linked to the worsening climate crisis of recent years. So how can communities better adapt to the climate to limit losses?
After flooding in Western Europe killed at least 200 people in 2021, Mesari Becker, a civil engineering professor at the University of Siegen in Germany, who focuses on sustainable architecture and design, said in an interview with DW that earthquake-resistant buildings are worth studying when it comes to transforming buildings to withstand flooding.
In these buildings, the depth of the foundation, structural design and building materials are specifically selected to cope with extreme flooding.
"We need to reinforce the basements so that they can also be filled with water so that people can get to safety quickly," Mesari-Becker said. ”
Other measures highlighted by the experts include the installation of retention valves at sewer connections to prevent flooding into homes, and the installation of waterproof windows and doors on the lower floors of buildings.
Tick, a professor at the University of Potsdam who focuses on natural disasters, told DW about the 2021 floods: "Our damage assessment shows that private preventive measures can significantly reduce flood losses. She also noted the need to protect potentially damaging elements, such as fuel canisters used to heat homes.
"Fuel can penetrate deep into masonry and damage neighboring buildings," she said. Flood control measures can prevent oil tanks from tipping over, reducing damage to buildings and the natural environment. ”
Urban flood control: better flood management
It's not enough to focus on buildings. Cities and other urban areas first need to consider controlling floods before they threaten to flood their basements, strengthening reservoirs and dams, and helping to store sudden floods.
Flooding in the Aarer region south of the German city of Bonn in 2021 showed that small streams in narrow valleys can turn into deadly torrents in hours because they don't have much room to spread out. In these places, Mesari-Becker said, dams and levees need to be raised and expanded to better protect cities from high water levels.
But it will be very expensive. For example, just expanding a levee would require at least 1 million euros per kilometre. The narrower the valley, the higher the cost of such measures.
Lehmann, professor of hydraulic engineering at the Technical University of Darmstadt, Germany, said: "In order to effectively protect infrastructure from such extreme events, our current water management and hydraulic engineering systems are not designed enough – as the current dire consequences show. ”
Experts stressed the urgency of protecting aging infrastructure over the next decade, but after the 2021 floods in Germany and Belgium, Lehmann said we can't expect better building measures to solve everything.
"From a technical, economic and practical point of view, it is impossible to completely reassess, rebuild and protect all elements of our built environment and infrastructure due to such extreme weather events," Lehmann said. ”
Natural flood control: control is not as good as dredging
Planning architects and engineers must find ways to work with the natural world rather than try to control it. Whenever possible, watercourses should be allowed to flow as nature wants, rather than altered or straightened – doing so will concentrate and accelerate the amount of water when floods come.
Instead of restricting the river, the levee should be moved back to make room for flood zones – open green spaces that act as overflow reservoirs during floods. At the beginning of the 21st century, these spaces were expanded along the Elbe River after several devastating floods on the Elbe River in eastern Germany.
Another approach is to improve the permeability of urban areas, making it easier for water to be absorbed on a larger scale, rather than being concentrated in specific places.
The town of Lechlingen, southeast of Düsseldorf, Germany, has suffered severe flooding several times in recent years. To ease the pressure on water management, the local area has been experimenting with a new planning model known as the "sponge city".
The idea is to direct rainwater from rooftops, squares and streets into grassy ditches by the side of the road. The excess water will then be naturally drained and added to local groundwater, reducing the burden on water management infrastructure. In addition, a back-up cistern will be installed to collect overflowing water for watering urban green spaces.
Hongzhang Xu, a major in urban planning and infrastructure development at the Australian National University in Canberra, told nature that while China's sponge city strategy is "very ambitious," it is not yet designed to withstand extreme storms like Dusuri. He said existing facilities need to be updated to cope with greater rainfall and implemented in parallel with other methods, such as improving drainage systems to "divert water away as quickly as possible."
Personal flood protection: improve emergency response capabilities
If people are overwhelmed by flooding, no amount of improvement in infrastructure and water management systems will help. Therefore, Lehmann stressed the need to raise public awareness.
"Especially in the case of flash floods caused by extreme weather, there is not only a lot of water, but also a lot of floating debris, garbage and other things that move with the water," he said. He noted that people entering these places are at risk of drowning and being crushed.
He said there was a need for ongoing educational campaigns to teach the public how to respond in extreme situations, for example, how to escape from a car caught in a current.
"Get out of the water as quickly as possible and get to safety — we should be teaching these kinds of rules of conduct as early as elementary school," he said, "and in emergencies, this can save lives." ”