Atmosphere And Weather

Causes of Cumbrian Floods

Marvin Somers's image for:
"Causes of Cumbrian Floods"
Image by: 

The Cumbrian floods in late 2009 were caused by a combination of excessive rainfall, urbanisation and inadequate flood defences. Prior to the event, areas in the north of England and Scotland had already received the full average amount of rainfall for November; with the ground already saturated, record amounts fell over a 72 hour period at the end of the month, causing record high flood surges and millions of pounds worth of damage as a result. Some have blamed global warming for the record rainfall levels though whether this is actually true is unclear.

From Wednesday 18th November 2009 various parts of northern England and Scotland received record amounts of rainfall. Some areas of high ground received around 400mm in 72 hours, while Seathwaite received over 300mm in just one day.

Because it had been raining relatively heavily for several days before the event, the ground was already saturated. There is a certain capacity for soil to absorb rainfall but this had already been met – as a result, the majority of the water ran quickly over the ground and into the rivers rather than slowly seeping down into the water table.

Another contribution to this speed was the precipitous ground of the Lake District. The steep hills and narrow values quickly concentrated the water in the rivers. Furthermore, increased urbanisation in many areas decreased the capacity of the valley areas to cope with the increased runoff, further concentrating water in the rivers.

The flood defences were not built to cope with such a surge and while defences near Carlisle that had been improved in 2005 held other areas had inadequate systems that failed under the deluge.

Several million pounds worth of damage was inflicted; however after the event charitable funds succeeded in raising a great deal towards repair while government aid covered the difference. The damaged areas were rebuilt while a series of small improvements designed to increase capacity were added to flood defences around Cumbria and the Lake District.

Since the event, there has been increased discussion in the area and around the country of the impacts of global warming on the UK climate. While global warming will potentially increase the spread of desert lands around the world it has the potential to make UK winters wetter and more intense. It is not clear whether the increased rainfall was the result of global warming but many in Cumbria now believe that their livelihoods are directly affected by the phenomenon.

More about this author: Marvin Somers

From Around the Web