Yorkshire Philosophical Society

Event Information

Is the history of flooding at York representative of UK and European flood trends?
Dr Neil MacDonald, School of Environmental Sciences, University of Liverpool

The last two decades have witnessed several large floods in York, but have these floods really been exceptional? Instrumental river flow series rarely extend much beyond 60 years in length, with relatively short instrumental series presenting considerable challenges in determining flood risk from high-magnitude floods. However, historical records permit a much longer-term analysis of flooding, with historic settlements such as York providing a valuable insight, not just into the quantitative elements of flood measurement (magnitude, discharge, level or extent), but also information on date/timing, damage, impacts, responses and the flood generating mechanisms. This talk explores how the additional information available within historical accounts can provide a fuller picture of extreme flood event at York, but how such information can also be used from multiple sites to examine questions around both long-term UK and European flood risk.

In partnership with the “Royal Geographical Society” and “Place”

Member’s report

Floods are not unusual, but extreme flood events are relatively rare and are well-remembered for a while. Collective memory is important as a warning from the past – when it lapses and the potential for flooding is forgotten, complacency leads to mistakes. Mapping events and their causes offers the possibility of calculating the likelihood of future events and making appropriate policy decisions about managing flood risk and includes, for instance, the siting of housing estates.

The construction of long meteorological and hydrological series comes from river gauge evidence and lake sediments, as well as city records, newspapers, insurance datasets and informal sources such as diaries, flood markers, woodcuts and folksongs. York has kept one of the longest records: dating from 1263, it provides a useful longitudinal measure of flood frequency and seasonality.

The trend in the UK and north-western Europe is for an increase in larger floods. Volcanic activity, atmospheric pressure, solar magnetic activity, the condition of the soil, peat water levels, the Atlantic Meridional Oscillation and sea temperature, are all implicated.

Carole Smith

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