BBC - Weather Centre - Features - Understanding Weather (original) (raw)

Exceptional weather conditions combined with a spring tide produced one of the worst floods in living memory for the east coast of England. Over 300 people lost their lives and damage in today's money was estimated at over £5 billion.

What caused the flooding?
The flooding was caused by a storm surge. A storm surge is primarily caused by the wind pushing the sea towards the coast, but can also be coupled with low air pressure. If pressure decreases by one millibar, the sea level rises by one centimetre. While this doesn't sound much, across the whole sea this can represent a significant volume of water.

...winds drove the storm surge southwards causing devastating floods...

Key events in the development of the depression:
From 1800 on 31st January, winds drove the storm surge southwards causing devastating floods along the east coast reaching Canvey Island just after midnight on 1st February then continued around the North Sea basin to devastate the Netherlands. Hurricane force winds were recorded at Felixstowe at 2000.

In total, 307 people in the UK were killed and almost 100,000 hectares of eastern England were flooded, while in the Netherlands, 50 dykes burst and 1,800 people drowned. The sea reclaimed over 200,000 hectares of polder country.

Why was there no warning?
In 1953 there were no satellites or computers to make an accurate forecast, and there was no single body responsible for flood warnings.

While communities did have emergency plans, many telephone lines had been brought down by the gales and affected by the flooding, so large scale evacuations were not possible.

Virtually no warning of the impending disaster was passed to the southerly counties until it was too late.

What has happened since?
Anthony Eden's Conservative government implemented one of the largest ever programmes of building and strengthening of sea defences. However, by 1993, 41% of these were in 'moderate' or 'significant' need of repair.

An inquiry into the disaster recommended that a flood warning organisation be set up. The Met Office responded by helping to establish the 'Storm Tide Forecasting Service', who provide 24 hour forecasts of tidal surge and wave activity.

In 1989, the National Rivers Authority was formed to oversee flood defences in England and Wales. Then in 1996 the Environment Agency was created, giving them overall responsibility for flood defences and flood warnings.

Forecasting accuracy has increased dramatically since the introduction of computer models, both meteorologically and in forecasting surges and coastal water levels.

The future
The east coast of Britain has always been at risk of coastal flooding, and we have been doing our best to resist this since the Romans first built earth banks to protect from coastal flooding some 2000 years ago.

...floods of 1953 were a "once-in-250 year event"...

The devastating floods of 1953 were a "once-in-250 year event". Following the publication of the 'Climate Change Scenarios for the UK' by the UK Climates Impacts Programme, in April 2002, Environment Secretary, Margaret Beckett said that although

"the rise in the UK average sea level may further threaten some low-lying unprotected coastal areas, it is the extremes of sea level storm surges and large waves that could cause most damage".

Sea levels are expected to rise around the UK, and could reach between 26 and 86 cm above the current level in south east England by the 2080s.

Researchers predict that at some east coast locations, extreme sea levels that currently have a 2% chance of occurring could occur 10-20 times more frequently by the 2080s.

The chances of storms and high tides coinciding will continue to increase, so forecasters and warning agencies are facing increasing challenges in warning and protecting coastal communities against flooding.