Science Story

04 July 2009 12:51 BST

Britain set to enter 'flood-rich' period

Extreme floods may be associated with foreign countries, but an expert is warning today that the UK could be set for the extreme weather in years to come.

Professor Stuart Lane at Durham University says that after 30 to 40 less eventful years, the UK seems to be entering a flood-rich period.

He predicts that more flooding is likely over a number of decades.

His research, published in the journal Geology, analysed long-term river flow and rainfall records dating from 1853.

This revealed that there have been fluctuations between very wet and very dry periods, each lasting for a few years at a time, as well as very long periods of a few decades that can be particularly wet or particularly dry.

From the early 1960s to 1990s the UK was relatively flood free, which Professor Lane says has lowered our own awareness of flood risk in the UK.

This is a concern as he believes the country is now entering a flood-rich period that it has not seen for a number of decades.

"We have not been good at recognising just how flood-prone we can be," Professor Lane warned.

"More than three-quarters of our flood records start in the flood-poor period that begins in the 1960s. This matters because we set our flood protection in terms of return periods – the average number of years between floods of a given size."

He continued: "We have probably under-estimated the frequency of flooding, which is now happening, as it did before the 1960s, much more often that we are used to.

"The problem is that many of our decisions over what development to allow and what defences to build rely upon a good estimate of these return periods."

Professor Lane's warning comes on the same day that a report from the environment, food and rural affairs committee says there was a total lack of awareness about the vulnerability of large parts of the country to flooding until the heavy rainfall of last summer.