Note on the 60th Anniversary of the 1953 North Sea Floods
Feb 01, 2013
This February 1 marks the 60th anniversary of the 1953 North Sea floods, one of the most devastating natural disasters to strike Northern Europe in modern times. A spring tide interacting with a violent extratropical cyclone raised sea levels to more than 2.5 m above normal high tide levels in some places. In total, more than 2,500 people lost their lives across the UK, Belgium, the Netherlands, and at sea, while about 70,000 properties and more than half a million acres of land were inundated. Losses in the UK were estimated at the time to be between GBP 40 million and GBP 50 million from physical damage alone. In the Netherlands, the cost was estimated at approximately 1 billion guilders. As AIR prepares an article that reflects back on the 1953 flooding to be published in the February issue of AIR Currents, we take a brief moment here to mark the event and recall the circumstances surrounding the disaster.
On January 29, a low pressure system developed in the North Atlantic that deepened rapidly the next day from a central pressure of 988 mb to 968 mb. The system passed north of Scotland and then turned toward the southeast into the North Sea on the 31st. Around the same time, a large high pressure system formed off the southern coast of Iceland and pushed eastwards, interacting with the deep depression and causing a steep pressure gradient running from north to south across the entire British Isles. Winds of over 90 km/h were reported along the length of Britain, causing large swells in sea levels along the east coast. To the south, a funneling effect occurred between the coasts of the UK and the Netherlands, further exacerbating the already high spring tide. The surge resulted in waves of up to 8 m in the western North Sea.
The first of the flooding began on January 31 along a 1,000 km stretch of the east coast of the UK. Coastal flood defenses were overwhelmed and seawater swept a few kilometers inland, resulting in 307 fatalities. Approximately 30,000 people were forced to evacuate their homes. At 4 a.m. on February 1, the surge waters reached the coast of the low-lying Netherlands. Damage in the Netherlands was even more severe than in the UK, with over 1,800 fatalities and almost twice as much land inundated. The worst affected area was Zeeland province in the southwest of the country.
As in the UK, many coastal defenses in the Netherlands were overwhelmed by the surge waters and hundreds of breaches were reported. In the aftermath of the event, UK and Dutch authorities dedicated resources to strengthening and improving existing flood defenses. In the Netherlands, the Delta Works program was launched to protect against surges with return periods of up to 1 in 10,000 years. In the UK, many flood defenses were built in the decades that followed, including the Thames Barrier that protects London from surges with a return period of up to 1 in 1,000 years. And while weather authorities were able to anticipate dangerous surge conditions in 1953, there was no system in place at the time to effectively disseminate warnings to the general public. As a result, in addition to improved flood defenses, comprehensive flood warning systems have been installed on both sides of the Channel.
AIR continues to work to improve our ability to model coastal and inland floods in Europe. In the February issue of AIR Currents, we will take a closer look at the 1953 event and discuss what factors should be taken into consideration when estimating the future risk from large coastal floods.