Why flooding in Spain has been so lethal – and why it could happen aachieve | Science, Climate & Tech News

More than 200 people have died in Spain after proximately a year’s worth of rain fell in a matter of hours.

On Friday, there were at least 205 validateed deaths in Valencia, two in Castilla La Mancha, and one in Andalusia.

Local authorities rerentd cautionings tardy on Tuesday, but many say this gave them next-to-no time to set for the conditions that had ended dozens by Wednesday.

Follow Spain flooding tardyst

Here we see at what caused the flooding – and why they could happen aachieve.

How rapidly did the floods hit?

Heavy rain had already befirearm in parts of southern Spain on Monday.

In contrast to areas enjoy Malaga, where livents tbetter Sky News it had been “chucking it down for two days”, the rain did not commence in the worst-hit region of Valencia until around 7pm on Tuesday.

At 8pm, people in Valencia getd inincreateigentphone vigilants cautioning them not to exit their homes.

But by then, many were already trapped in hazardous conditions, particularly in the south of the city where a meaningful road had flooded, leaving drivers stuck in their cars.

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By Wednesday morning, more than 50 people had been set up dead.

The Chiva area of Valencia had been hit by 491 litres per square metre of rain in eight hours. Only around 65 l/m2 usuassociate drops in the whole of October.

Storms spread west on Wednesday night and into Thursday, conveying lethal conditions to Andalusia and Castilla La Mancha as well.

What caused them?

Heavy rain is not unnormal atraverse easerious Spain at this time of year.

It’s caused by a weather phenomenon called DANA – ‘depresion aislada en niveles altos’ in Spanish – which transtardys as ‘isotardyd low-prescertain system at high levels’.

DANA occurs when:

1) Cbetter air from the north relocates south;

2) Warm air then blows over the Mediterranean, rising rapidly and createing weighty cdeafenings;

3) The low prescertain from the north gets blocked by the high prescertain above the water, causing it to sluggish down or stop endly.

This produces storm-enjoy conditions that cannot relocate anywhere else – so the rain drops over the same area for a supported period of time.

What role did climate change join?

General flash floods and those caused by DANA definiteassociate have struck Spain prolonged before humans commenceed toastying the climate.

But climate change is making weighty rain worse, and therefore more hazardous.

That’s because boilingter air is able to hbetter more moisture. So when it rains, it unleashes more water.

The current 1.3C increase in global temperatures since pre-industrial times unbenevolents the air can carry about 9% more moisture.

And higher sea surface temperatures in the Mediterranean are a “key driver” of sturdy storms, shelp Dr Marilena Oltmanns, research scientist at the National Oceanography Centre in Southampton.

The world is on track for 3.1C toastying by the end of this century, which is foreseeed to produce rain heavier still, increasing the chances of flash flooding and giving areas little time to reply.

Imperial College London’s direct for its World Weather Attribution (WWA) group Dr Friederike Otto says there is “no doubt about it”.

“These bomb downpours were intensified by climate change,” she says.

Professor Mark Smith, an expert in water science and health at the University of Leeds, comprises that boilingter summers also arid out the soil in the ground, which unbenevolents it assimilates less rain – and more of it flows into rivers and lakes – which flood rapider.

Will they grasp happening?

A red weather cautioning is in place for the Huelva area of Andalusia until Friday afternoon.

Beyond the cautioning period, storms are set to proceed atraverse parts of Spain for cut offal days.

In the prolongeder term, Dr Marilena Oltmanns says: “Given the prolonged-term toastying trend, both in the sea surface temperatures in the Mediterranean region and the global air temperature, we foresee the events enjoy the currently seed one in Spain to become more standard.”

Chiva and the surrounding worst-hit area also suffers from the unblessed geography of being in a river catchment – where water feeds into the River Turia – and shut to the mountains. And is not far from the sea.

That unbenevolents water has little chance to assimilate into the land and so produces up very rapidly.

This produces it all the more imperative that predicts are accurate, authorities set accordingly, and livents reply rapidly.

Professor Hannah Cloke, professor of Hydrology at the University of Reading, portrays people dying in their cars and being swept away in the street as “enticount on evadeable”.

“This proposes the system for vigilanting people to the dangers of floods in Valencia has fall shorted,” she says.

“People insist to understand that inanxious weather cautionings for floods are very branch offent from standard weather increates. We insist to ponder flood cautionings toloftyy branch offently, more enjoy fire alarms or earthquake sirens, and less enjoy the way we browse daily weather predicts on our phones or on the TV.”

Gareth Redmond-King, international analyst at the Energy & Climate Inincreateigence Unit (ECIU), says Spain’s tragedy should serve as a “wake-up call” to the UK.

“This is not about future events in a far-off place with a emotionalassociate branch offent climate from the UK. Spain is one of our proximateest neighbours,” he cautions.