Modern-day flooding is not unprecedented, claim experts
After Storm Desmond caused chaos across the country, Aberystwyth University’s Professor Mark Macklin says present-day floods are not unprecedented and there are many historic examples of such flooding. Robin Turner reports...
THE recent “unprecedented” flooding in north-west England might be more common than currently believed, a Welsh scientist is warning.
Professor Mark Macklin, an expert in river flooding and climate change impacts at Aberystwyth University, says analysis shows 21st century floods are not unprecedented in terms of either their frequency or magnitude.
Working with other experts from the universities of Cambridge and Glasgow, he has drawn on historic records to build a clearer picture of the flooding.
They conclude that 21st century flood events such as Storm Desmond are not exceptional or unprecedented in terms of their frequency or magnitude and that flood frequency and flood risk forecasts would be improved by including data from flood deposits dating back hundreds of years, not just a few decades.
Prof Macklin said: “Sometimes we are talking about a ‘one in a hundred year flood’ based on records going back just 30 years.”
He added: “UK documentary records and old flood deposits dating back hundreds of years indicate that these floods are not unprecedented, which means we are grossly underestimating flood risk and endangering people’s lives.
“The truth is flood plains are made by floods and, after the industrial revolution and because of need for land, we are building on them.
“For flooding to occur in flood plains and for it to be termed ‘unprecedented’ therefore does not make much sense.”
Prof Macklin points out the floods in Talybont in 2012 followed on from a long series of floods in the area, some going back to the 1600s.
He has studied flood deposits from flood plain area across the UK including a number in Wales using “lichen clocks”.
He explained that by examining the rate at which lichen grows on boulders disturbed by floods, the date of the floods can be determined and he has found severe flooding going back hundreds of years.
He warned: “It is of concern that historical data suggests there is far more capacity in the North Atlantic climate system to produce wetter and more prolonged flood-rich periods than hitherto experienced in the 21st century.
“Looking forward, an increased likelihood of weather extremes due to climate change means that extending our flood record using
Rheidol, September 1842: One witness said: “A noise was heard resembling distant thunder...a tremendous body of water rolled several feet above the waters of the River Rhydol, stripping the fields of hay, wheat, oats and barley.”
March 18, 1947: Ceredigion and Powys, Dyfi and Teifi – due to the rapid thaw and heavy rainfall, hundreds of acres of farmland were inundated. In Cardiganshire, considerable flooding resulted.
December 1960: The River Ogmore bursts its banks in the centre of Bridgend hitting shops, businesses and many homes in the town centre, the abattoir, Bridgend rugby field and clubhouse while Newbridge Fields became a lake.
March 1972: Around 500 homes flooded when the River Afan bursts its banks in the centre of Port Talbot.
February 26, 1990: 2,800 houses evacuated in Kinmel Bay and Towyn as the sea flooded the area.
June 8, 2012: Widespread flooding hit areas including Talybont. The Leri, Rheidol and Clarach areas were worst affected. geomorphology science must be placed at the centre of flood risk assessment in the UK.”
Professor John Lewin, also from the University of Aberystwyth, said: “What is needed is far more resilience for already-developed floodplains, and much more serious insistence that future floodplain development should be virtually curtailed.
“Somewhere along the line flood plain development has been allowed by local authorities and the UK government to continue regardless.”
Lewin, Macklin and their colleagues are members of the British Society for Geomorphology’s Working Group on Stormy Geomorphology, who are currently finalising a global analysis of the role geomorphology science can play in an age of extremes.