AIR Worldwide Releases UK Inland Flood Model

AIR Worldwide Corporation has released the AIR Inland Flood Model for Great Britain. “The new probabilistic model will help companies better manage on-and-off flood plain risk for properties in England, Wales, and Scotland,” said the announcement. “It covers residential and commercial lines of business including Alternative Living Expenses (ALE) and Business Interruption (BI). The model incorporates original research by AIR that has been peer-reviewed by a team of leading flood risk experts in the U.K.”

Dr. Milan Simic, AIR Worldwide Managing Director, explained: “After the record breaking insured losses caused by the summer floods of 2007, the need for a fully probabilistic model has never been greater. The AIR Inland Flood Model for Great Britain breaks new ground in flood risk assessment. It captures the complexities inherent to the flood peril, including accounting for the multiple sources of flood water, land cover and existing soil conditions, man-made flood defenses, and the impact of flood waters of varying depth on property.”

AIR said its new model “captures storm systems of varying size—from large-scale events affecting the entire country to highly localized thunderstorms. Using results from Numerical Weather Prediction (NWP) modeling, AIR has developed an innovative and sophisticated rainfall generation module that produces a realistic simulation of rainfall patterns that account for storm duration and the geographic area of rainfall.”

“I’m very impressed with AIR’s flood model,” stated Dr. Stuart Lane, Professor of Physical Geography at Durham University and a member of The AIR Inland Flood Model for Great Britain peer review team. “There is major innovation ─ notably the rainfall representation ─ and I am certain that it will be fit for purpose and probably out compete others very quickly.”

AIR added that its “model incorporates a novel approach to estimating river run-off. The process incorporates pre-storm conditions based on five days of preceding rainfall activity, resulting in a long-term memory of pre-event soil conditions for each simulated event.

“With approximately 50 percent of the losses from the 2007 floods occurring off-flood plain and much of that loss occurring in highly exposed urban areas, AIR developed an explicit model for off-flood plain loss estimation. The off-flood plain model accounts for elevation, runoff, and the impact of drainage backups, facility aging, and other urban risks at each modeled location.

“AIR’s model estimates damage to buildings and contents caused by flood, by incorporating damage functions that vary by occupancy, construction, and height. Since flood damage is highly dependent on height, AIR’s model enables companies to analyze the risk to a specific floor or floors of interest, including basements. The model also accounts for alternative accommodation and the time required for drying and cleaning the property as well as business interruption losses which vary by occupancy and account for building size and complexity, and business characteristics such as resiliency and the ability to relocate.

“Losses from the AIR Inland Flood Model for Great Britain have been validated through extensive analysis of personal and commercial lines claims data from the 2007 floods, representing roughly 30 percent of the industry exposure.”

Source: AIR Worldwide – www.air-worldwide.com