The summer of 2007 was the wettest the United Kingdom has experienced since detailed record-keeping began in 1914. When it was over, the insurance industry had paid out approximately £3 billion on more than 165,000 flood insurance claims.
Innovative Rainfall Generation Model
AIR Worldwide launched its inland flood model for Great Britain a year later. Representing a major technological advance, the model incorporates an innovative rainfall generation module that leverages AIR’s expertise in numerical weather prediction (NWP) to produce realistic rainfall patterns in space and time.
“There is major innovation here—notably in the rainfall representation—and I am certain that it will be fit for purpose and probably out compete others very quickly,”
Durham University Professor Stuart Lane in his peer review of the model.
On- and Off-Floodplain Risk
The AIR model leverages high resolution soil, land use/land cover and topographic databases, coupling hydrology with hydraulics for a realistic representation of on-floodplain risk. However, as the historic floods of 2007 made clear, flood waters do not confine themselves to floodplains. In fact, nearly 50% of the losses from the 2007 floods occurred off-floodplain and much of that loss occurred in highly exposed urban areas. In the AIR model, off-floodplain flooding is modeled according to the physical characteristics of more than 15,000 small catchments in Great Britain. Urban drainage back-ups and the aging of facilities is modeled probabilistically—as is the failure of flood defenses, such as dams, levees and gates.
A Comprehensive Solution for a Complex Peril
Inland flood is a highly complex peril—and one that the UK insurance industry is required to underwrite. The AIR Great Britain Inland Flood Model captures the many complexities inherent in the peril, the property damage that can result, and the ultimate insured losses. In doing so, it meets the risk management needs of companies pricing and underwriting flood risk in England, Scotland and Wales.
AIR currently offers an inland flood model for:
Listed below are additional materials of interest to our clients exposed to inland flood risk in Great Britain: