Comparing the scale of modelled and recorded current flood risk: Results from England

As the Sendai framework recognises, understanding the nature and severity of risk is an important prerequisite to sensible risk reducing measures. The UK has been in the forefront of assessing the scale of flood risk at a national level to inform investment and policy directions but the scale of this risk, as modelled, has reduced since 2014. This paper compares the most recent modelled version of national flood risk, in the form of the Environment Agency's State of the Nation report, with loss figures quantified in terms of insurance claims data for the period 1998 to 2018.

Depending on assumptions, the results show that the modelled results are between 2.06 and over 9.0 times the comparable flood losses measured in terms of the compensation paid to flood victims by insurance companies. The reasons for these differences remain unclear but several possibilities are reviewed. Many of these reasons appear implausible, but the divergence between the two sets of results should encourage the users of this data to consider carefully their assessments of the true scale of flood risk that the country faces, and perhaps promote similar comparisons in other countries.