Professor Rob Lamb from Lancaster University’s Environment Centre and the JBA Trust has teamed up with Professors David Archer and Hayley Fowler from Newcastle University, and Sam Watkiss and Sarah Warren from industry partner JBA, to digitalise and map the trends of historical flooding across the North of England.

Abrupt wave front floods (AWFs) have been referred to in news articles and other historical records across the Pennines for centuries. AWFs are a specific type of flash flood, typically brought on by periods of intense heavy rainfall, and are characterised by an extreme and sudden rise in a river’s water level in what is known colloquially as a ‘wall of water’. The speed at which the water rises presents the biggest risk of loss of life and property damage – and their frequency and unpredictability is becoming of increasing concern.

To better understand this phenomenon, Professor Archer has collated local news articles and other anecdotal records on floods dating from the early 1700 through to the year 2020 to try and ascertain what – if any – patterns exist in the occurrence of AWFs. In conjunction with these historical accounts, the team also examined river level data measured at gauges in recent decades to supplement the written historical accounts. From these records, the team have created the first and only digital archive of this particular type of flash flooding in Britain, which they hope will aid fellow researchers and flood risk managers, and ultimately help reshape modern approaches to hydrology with a new generation of flash-flooding models.

“We want to draw attention”, commented Professor Lamb, “to the fact that this class of hazard exists, but isn’t always highlighted in the way flood risks are assessed or predicted, so often these sorts of events come as a surprise. From a technical perspective, the way that we analyse flooding, the way we build models and the types of models that are used in operational flood management and planning don’t necessarily set out to represent these types of events – and such models may not even be able to account for them accurately. Our study takes a more holistic approach to what the risks are, revealing phenomena that are less explored or less well understood. It highlights the need to assess the whole spectrum of flooding events that occur in our rivers, not just the peaks”.

The JBA Trust – a knowledge exchange charity who helped to carry out the research – are hosting the database on their website. The aims for the future of this project are to make the database more accessible to encourage other researchers and practitioners to explore its contents and to inform flood forecasts, risk assessments and future developments in the modelling of flood hydrology.