Geomorphology and changing flood risk in the UK

Although the changing nature of rivers are well known by geomorphologists, it is largely unappreciated by many people in the insurance industry who have tended to view rivers in the UK, especially heavily engineered systems in urban and lowland contexts, as fixed in size, form and position. However major flood events in the UK over the last decade, including the ‘Millennium Floods' of Autumn 2000, Boscastle in August 2004, the Summer floods of 2007, and those in Cumbria in November 2009 have radically changed this perception, demonstrating that rivers are not passive backdrops to the business, industrial, urban and agricultural use of floodplains. River channels and floodplains can and do change rapidly with sometimes catastrophic consequences for communities, farms and industry.

With climate modellers predicting more flooding in the UK, the rates of river bed and bank erosion and floodplain sedimentation are also likely to accelerate. What is also becoming increasingly clear is that it is not always environmentally or economically prudent nor practical to exclusively focus efforts on engineering solutions to flooding problems caused by the encroachment of properties onto floodplains, and potentially made worse by climate change. A more informed way of using geomorphological science and data is required that identifies those sites most at risk and targets our increasingly limited resources at these areas. This is a new way of thinking and should be considered as additional and complementary to the more traditional, ‘hard' engineering approaches to flood defence.

The principal aim of this report is to examine the current research agenda as it relates to vulnerability points in river systems, and to make recommendations where future research and resources may be most useful and which the insurance industry should prioritise.