Huge ravines that swallow entire neighborhoods threaten more and more cities. A global phenomenon aggravated by climate change

A busy street in Buriticupu, a city in northeastern Brazil, has now reached a wide chasm with a depth of 80 meters – a 20-story building would fit in it. Canyons formed by soil erosion are advancing at an alarming rate, destroying thousands of homes in Latin America and Africa and threatening fertile farmland in parts of China, the US and Europe, according to the BBC.

The locals of Buriticupu call these canyons “voçoroca” or “torn earth”, in the language of the native Tupi-Guarani. The phenomenon is a result of deep gully erosion, one of the most aggressive forms of soil degradation caused by rain and waste water.

The experience of a former police officer in Buriticupu, whose car fell into the chasm in the middle of the town while returning from a party at night, is just one of many examples that demonstrate the risks to which the town’s 70,000 residents are exposed.

As more ravines form in this city on the edge of the Amazon jungle, Buriticupu could end up being torn in two. The city has around 30 such craters, and the first two largest are less than 1 kilometer apart.

“If the authorities don’t stop this, the two ravines will meet and form a river,” said Edilea Dutra Pereira, a geologist and professor at the Federal University of Maranhão.

Ravines have been part of Earth’s geological history for millions of years, but Pereira and other experts say today’s are expanding faster and they fear more will appear because of climate change that may make rains more intense .

Chasms over 2 kilometers long swallow entire neighborhoods

Brazil is the most affected country in Latin America, but Mexico, Colombia, Ecuador and Argentina also suffer from the same problem. Furthermore, African countries such as Angola, the Democratic Republic of Congo and Nigeria, where some ravines are over 2 kilometers long – are also affected by this phenomenon.

Although there is no official data on the victims of this phenomenon, the authorities in Buriticupu say that the ravines swallowed at least 50 houses, and other locals were forced to leave their homes, leaving behind entire neighborhoods abandoned.

Deforestation also plays an important role in this type of soil erosion. Buriticupu is now an arid and stony place, but it is part of the Amazon jungle region and was once covered with vegetation such as cedar, courbaril and ipê.

In the 1990s, the logging industry exploded – more than 50 sawmills worked here 24 hours a day. 20 years later, most of the vegetation around the city has disappeared.

In the first months of 2023, the Brazilian state of Maranhão experienced the worst floods in history. More than 60 localities entered a state of emergency, thousands of people were left without homes and dozens of them died.

As rains continue to intensify, the risk of new gullies will double or even triple globally.

The capital of DR Congo, Kinshasa, has hundreds of urban ravines – one of them is over 2 kilometers long. In total, there are 165 kilometers of ravines formed inside the city, which has a population of 12 million people.

In a single night of heavy rain in December 2022, 60 people died when their houses collapsed into a ravine in Kinshasa.

The population of the DR Congo capital will grow to 20 million in 2030 and 35 million by 2050, making it Africa’s largest megacity, according to the World Bank.

Editor: Raul Nețoiu

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