South Africa, the most industrialized country on the continent, has largely escaped the tropical cyclones that regularly hit its neighbours.
But last week, storms hit the city of Durban on the east coast, causing heavy flooding and landslides that killed more than 440 people.
Here are the main issues behind the floods and devastation.
Has climate change played a role
Meteorologists say the storms weren’t tropical.
Instead, the rains were part of a normal South African weather system called “cut-off low” which can bring heavy rain and cold weather.
“Cut low pressure systems are common. Their frequency becomes high during the autumn and spring seasons, and their strength differs,” said Puseletso Mofokeng of the South African Meteorological Service.
Some of these systems are very intense, causing heavy rain, hail, strong and potentially damaging winds, and heavy snowfall.
A low threshold in April 2019 killed 85 people in the Eastern Cape and KwaZulu-Natal provinces.
While the storm system itself is a known phenomenon, the difference this time was the intensity of the deluge.
Here, experts point to climate change – warmer seas load the atmosphere with more moisture, which is then dumped as rain.
“We’ve seen three (severe) floods in Durban in less than 10 years. Does it have anything to do with climate change? Definitely,” said Mary Galvin of the University of Johannesburg.
“We are feeling the impact of what are certain to be unpredictable, more frequent, severe and extreme weather events.”
A recent UN report indicates that what was once thought to be a 100-year flood could end up happening several times a year by 2050.
Why is Durban prone to flooding?
Durban experiences floods every year, but not as severe as these.
The city is built on a hilly area with many gorges and ravines – a topography that University of KwaZulu-Natal town planner Hope Magidimisha-Chipungu says is prone to flooding.
If the ground isn’t properly “stabilized in hilly areas, obviously you’re going to have landslides,” she said.
Some have suggested that Durban’s stormwater drainage system may not have been well maintained, which authorities in the 187-year-old city dispute.
The city of Durban is not alone in experiencing extreme weather conditions in South Africa.
Along the west coast, Cape Town nearly ran out of water during a drought in 2018.
“Climate predictions and all models show that the wetlands will get wetter and the dry areas will get drier. So Durban… will unfortunately be wetter,” Galvin said.
What about planning?
Durban is one of South Africa’s fastest growing cities, with economic growth above the national average in 2015.
Massive and unplanned migration created housing shortages, leading to the proliferation of shacks, locally referred to as informal settlements.
“The way South African cities were designed was very exclusive in nature,” said urban planner Magidimisha-Chipungu.
“Land-use planning and the legacy of apartheid (placed) the urban poor on the periphery and in low-lying areas” along the riverbanks, she said.
About a quarter of the metro’s 3.9 million inhabitants live in 550 informal settlements around the city. At least 164 of them were built on floodplains, according to Galvin.
A host of recent crises have further sapped resources – the coronavirus pandemic, massive unemployment, the riots and looting that erupted last year.
It’s “like the seven plagues” that follow one another, Galvin said.
Researchers investigate heavy rains on Australia’s east coast
© 2022 AFP
Quote: What’s behind the floods in South Africa (April 18, 2022) Retrieved April 18, 2022 from https://phys.org/news/2022-04-south-africa-disaster.html
This document is subject to copyright. Except for fair use for purposes of private study or research, no part may be reproduced without written permission. The content is provided for information only.