Unprecedented rainfall has caused flash flooding in countries from the US to India, China, the UK and Spain in recent days.
22 people were killed when a bridge flooded and many homes were destroyed in the Indian state of Himachal Pradesh on Sunday.
Over the weekend, the extremely heavy onset of the monsoon meant that many districts in the northern state received a month’s worth of rain in one day. The deluge was also responsible for the landslide in Pakistan – a senior weather department official told Reuters.
More heavy rain is also forecast, the department said, with flooded roads, traffic jams and power outages expected across the region.
The extreme heat caused unprecedented rain
Heavy rains also sparked flash floods and closed roads in New York’s Hudson Valley on Sunday night. At least one person died.
Bryan Jackson, a meteorologist at the US National Weather Service’s Weather Prediction Center, told Reuters that a weather pattern more typical of the colder months has established in the north and is associated with regular summer moisture.
Pennsylvania and southern New York state were hardest hit by Sunday’s rain, but the weather service is predicting widespread and severe flooding in parts of the New England state on Monday.
“We expect more local disaster impacts,” Jackson said. The weather service encourages people in vulnerable areas to seek higher ground immediately.
Earlier in the day, flash flooding in the northeastern Spanish city of Zaragoza led to cars being washed away on flooded roads. The footage went viral.
“Warmer air brings more water vapor. Record heat brings record rains brings record floods,” tweeted Eric Holthaus, a US-based meteorologist and journalist. of the climate, who also noted that the temperature could rise to 47 degrees Celsius (116.6 Fahrenheit) in Spain this week.
Strong summer storms also sparked flooding in the northern UK city of Sheffield on July 9.
Strategies for climate adaptation
With record flooding in countries from Germany to Pakistan linked to the worsening climate crisis, how can communities better adapt to limit the damage?
Speaking to DW after the 2021 floods claimed at least 200 lives in western Europe, Lamia Messari-Becker, a professor of civil engineering focused on sustainable construction and design at the University of Siegen in Germany, said to adapt buildings to withstand flood water, is worth looking into. in earthquake resistant architecture.
In such buildings, the foundation depth, structural design and building materials are specifically selected to withstand severe flooding.
“We need to reinforce the basements so that they are also filled with water and people can get to safety quickly,” Messari-Becker said. “It’s also about the strengthening measures needed for the exterior walls, for the roofs.”
Other measures advocated by experts include retaining valves in sewage connections, which prevent floodwaters from backing up into homes, and waterproofing windows and doors in low-lying areas. level of buildings.
“Our damage assessments show that private precautionary measures can reduce flood damage,” Annegret Thieken, a professor focusing on natural risk research at the University of Potsdam told DW due to floods in 2021. He also pointed out the need to secure potentially harmful elements such as fuel tanks used to heat homes.
“Fuel oil can seep deep into the masonry and also damage neighboring buildings,” he said. “In extreme cases, oil damage can make buildings uninhabitable. Flood proofing can prevent oil tanks from overflowing, reducing damage to buildings and the natural environment. “
Weatherproofing cities: sustainable approaches to flood management
It is not enough to just focus on buildings. Cities and other urban areas should think about controlling water before it has a chance to flood basements in the first place, by strengthening reservoirs and dams that help absorb the flash. surge.
Flooding is like that in destroyed the Ahr region south of the city of Bonn in Germany show that small streams in narrow valleys, where the water doesn’t have much room to spread out can turn into deadly torrents within hours. In such areas, Messari-Becker said dams and dikes need to be raised and expanded to better protect towns from high water levels.
But that’s not cheap. Just extending a dike, for example, can cost at least €1 million ($1.2 million) per kilometer. And the narrower the valley, the more expensive those steps are.
Boris Lehmann, a professor of hydraulic engineering at the Technical University of Darmstadt in Germany said that “to effectively protect the infrastructure against such extreme events, the current design of our water management and hydraulic engineering systems is not enough. – as today’s dire consequences show. ,”
Experts stress the urgency of future-proofing aging infrastructure over the next decade, but after the floods in Germany and Belgium, Lehmann said we can’t expect better construction measures to solve all our problems. .
“From a technical, economic and practical point of view, it is not possible to completely re-examine, rebuild and thus protect all elements of our built environment and infrastructure because of such which are extreme weather events.”
Nature-based solutions for flood prevention
That’s where planners and engineers must find ways to work with the natural world, rather than trying to control it. Wherever possible waterways should be allowed to flow as nature intended, and not be altered or straightened. Doing so concentrates and greatly accelerates water volumes during a flooding event, he said.
Instead of damming rivers, levees should be moved to create flood plains – wide open green spaces that can serve as reservoirs that overflow during floods. Those places are extended along the Elbe River in eastern Germanyafter several disastrous flooding events in the early 2000s.
Another way is to make urban areas more permeable, so that water can be absorbed more easily in a wider area and not concentrated in specific areas.
The German town of Leichlingen, southeast of Düsseldorf, has been hit by severe flooding several times in recent years. To ease the stress on their water management, they experimented with a new planning model known as the “sponge city.”
The idea is to channel rainwater from roofs, squares and streets into grass-covered gutters along the road. Excess water will be allowed to drain naturally and replenish local groundwater, reducing the load on water management infrastructure. Backup tanks will also be installed to collect overflow and be used to irrigate the city’s green spaces.
Emergency preparedness: empowering communities
Improving infrastructure and water management systems won’t help if people don’t know how to react when faced with a wall of water. That’s why Lehmann, the hydraulic engineering expert at the Technical University of Darmstadt, emphasized the need for a more public awareness.
“Especially in the case of flash flooding due to severe weather, it’s not just a lot of water – there’s also a lot of floating trash, garbage and other things moving in the water,” he said, adding that people going into it the water risks drowning and crushing. He said ongoing education campaigns are needed to teach the public how to react in extreme situations – for example, how to escape from a car stuck in a current.
“‘Run away from the water and get to safety as soon as possible’ – we need to start teaching such rules of behavior as early as elementary school,” he said. “In case of emergency, it can save lives.”
This is an updated version of an earlier article.