untitled design

Old dams and the climate crisis: Understand why the floods in Libya were deadly

It all started with a bang at 3 am (local time) on Monday (11), while residents of Derna, in eastern Libya, were sleeping. One dam broke, then a second, sending a huge wave of water rushing down the mountains toward the coastal city, killing thousands of people as entire neighborhoods were swept away by the sea.

At least 5,000 people in Libya have been killed by this week’s floods, Doctors Without Borders said in a statement on Thursday, revising a previous estimate.

The city of Derna, the epicenter of the disaster, had a population of around 100,000 before the tragedy. Authorities say at least 10,000 remain missing. A CNN was unable to independently verify the numbers.

See also: Deaths after rains in Libya could exceed 20 thousand

data-youtube-width=”500px” data-youtube-height=”281px” data-youtube-ui=”international” data-youtube-play=”” data-youtube-mute=”0″ data-youtube-id= “pkYTxrQnRtU”

Buildings, homes and infrastructure were “destroyed” when a 7-metre wave hit the city, according to the International Committee of the Red Cross (ICRC), which said on Thursday that bodies were now surfacing from the coast.

But with thousands dead and many more still missing, there are questions about why the storm that also hit Greece and other countries caused so much more devastation in Libya.

Experts say that beyond the powerful storm itself, Libya’s catastrophe was greatly exacerbated by a lethal confluence of factors, including aging, disintegrating infrastructure, inadequate warnings and the impacts of the accelerating climate crisis.

Storm in Libya

Fierce storm

The extreme rains that hit Libya on Sunday (10) were caused by a system called Storm Daniel.

After sweeping Greece, Turkey and Bulgaria with severe flooding that killed more than 20 people, it turned into a “medicane” over the Mediterranean – a relatively rare type of storm with characteristics similar to hurricanes and typhoons.

The medicane strengthened as it crossed the exceptionally warm waters of the Mediterranean, before dumping torrential rain on Libya on Sunday.

It brought more than 414 mm of rain in 24 hours to Al-Bayda, a city west of Derna, a new record.

Although it is too early to definitively attribute the storm to the climate crisis, scientists are confident that climate change is increasing the intensity of extreme weather events such as thunderstorms.

Warmer oceans provide fuel for storm growth, and a warmer atmosphere can hold more moisture, which means more extreme rainfall.

Storms “are becoming more ferocious due to climate change,” said Hannah Cloke, professor of hydrology at the University of Reading in the United Kingdom.

Flood history

Derna is prone to flooding, and its dam reservoirs have caused at least five deadly floods since 1942, the last of which occurred in 2011, according to a research paper published by Libya’s Sebha University last year.

The two dams that broke on Monday were built around half a century ago, between 1973 and 1977, by a construction company from Yugoslavia.

The Derna dam is 75 meters high and has a storage capacity of 18 million meters (4.76 billion gallons). The second dam, Mansour, is 45 meters high and has a capacity of 1.5 million meters (396 million gallons).

These dams have not been maintained since 2002, the city’s deputy mayor, Ahmed Madroud, told Al Jazeera.

But the problems with the dams were known. The Sebha University newspaper warned that dams in Derna had a “high flood risk potential” and that periodic maintenance was needed to avoid “catastrophic” flooding.

“The current situation at the Wadi Derna reservoir requires authorities to take immediate measures to carry out periodic maintenance of the existing dams,” the document recommended last year.

“Because in the event of a major flood, the result will be catastrophic for the residents of the valley and the city.”

It also found that the surrounding area lacked adequate vegetation that could prevent soil erosion. Residents in the area should be warned about the dangers of flooding, he added.

Liz Stephens, Professor of Climate Risk and Resilience at the University of Reading in the UK, told CNN that there were serious questions to be asked about the standard of design of the dam and whether the risk of very extreme rainfall was adequately taken into account, it adds.

“It is very clear that without the dam failure we would not have seen the tragic number of deaths it resulted in,” she said.

“The dams would have initially held back the water, and their failure would have potentially released all the water at once,” Stephens also told the Science Media Center, adding that “debris caught in the floodwaters would have increased the destructive power.”

Derna has been hit in the past and its infrastructure has been destroyed by years of fighting.

Since the fight against the Islamic State and, later, against the eastern commander Khalifa Haftar and his Libyan National Army (LNA), the city’s infrastructure has crumbled and is woefully inadequate in the face of floods such as that caused by Storm Daniel.

Lack of warnings

Better warnings could have prevented most of the casualties in Derna, said the head of the United Nations World Meteorological Organization, Petteri Taalas.

“If there had been a meteorological service operating normally, they would have issued the warnings and also the emergency management would have been able to carry out the evacuation of people and we would have avoided most of the human casualties,” Taalas told reporters at a press conference on Thursday. fair.

Talaas added that political instability in the country has impeded efforts by the World Meteorological Organization (WMO) to work with the Libyan government to improve these systems.

However, even robust early warning systems are not a guarantee that all lives can be saved, Cloke said.

Dam failures can be very difficult to predict and are fast and ferocious, she told CNN . “There is a monstrous volume of water that completely destroys the city,” Cloke said. “It’s one of the worst types of flooding that’s ever happened.”

While dams are generally designed to withstand relatively extreme events, that’s often not enough, Cloke said. “We should be preparing for unexpected events, and then you put climate change on top, and that increases those unexpected events.”

The risk that climate-driven extreme weather poses to infrastructure – not just dams, but everything from buildings to water supplies – is global. “We are not prepared for the extreme events that are coming,” Cloke said.

(Celine Alkhaldi, from CNN Mostafa Salem and Sharon Braithwaite contributed to this text)

Source: CNN Brasil

You may also like

Most popular