AIR Adds Storm Surge Feature to U.S. Hurricane Model

Catastrophe risk modeling firm AIR Worldwide (AIR) has updated its hurricane model for the U.S. to help insurers and reinsurers better understand and quantify the risk from hurricanes.

The update features a hydrodynamic storm surge module that integrates storm parameters with elevation data to simulate location-specific storm surge inundation depth and extent. Storm surge results from a combination of variables, including storm size, strength, speed, and path, as well as tidal heights and coastal geography.

“Hurricane storm surge can be devastating, resulting in substantial damage and high insured losses,” said Dr. Tim Doggett, assistant vice president and senior principal scientist, AIR Worldwide, in a statement on the product release.

Doggett said the steady growth in the value and density of property on the Gulf and East Coasts of the United States is increasing the need for reliable information on storm surge risk.

He said AIR’s new storm surge module represents “state-of-the-art modeling techniques and the latest research on storm surge hazard to accurately assess risk at very high resolution.”

The updated storm surge module incorporates the 30-meter National Elevation Dataset (NED) developed by the USGS — the same data set used in the AIR inland flood model for the U.S. It also uses a customized variation of the Sea, Lake, and Overland Surges from Hurricanes (SLOSH) model from the National Oceanic and Atmospheric Administration (NOAA).

The new storm surge module also incorporates regional and seasonal data on tide heights and contains up-to-date data on levees, seawalls, floodgates, pump systems and other mitigating structures and equipment — including the most up-to-date levee information available for New Orleans, according to the Boston-based modeling firm.

The model updates also include the most recent North Atlantic hurricane database from NOAA, the latest reanalysis data from 1930 to 1945, and the 2011 release of the U.S. Geological Survey (USGS) National Land Cover Database. Additionally, the vulnerability module incorporates the latest observational data on the impact of square footage on wind losses for large, high-value homes and important updates that reflect the latest findings on the vulnerability of manufactured homes.

Estimates of damage from storm surge take into consideration information on primary building characteristics such as construction, occupancy, and height, as well as a host of secondary characteristics including base flood elevation, foundation type, number of basement levels, floor of interest, and custom flood protection. These can be entered by the model user.

The model estimates physical damage and time-element losses using functions that reflect local building codes and regional design practices, as well as damage survey findings, claims analyses, and engineering research, according to AIR.

“Our view of hurricane risk in the United States has been refined by new hazard data, enhanced modeling of storm surge and flood defenses, and an improved understanding of building vulnerability,” said Doggett. “The highly granular estimates produced by the model can help insurers better understand the risk from hurricane wind and storm surge, supporting improved risk selection, portfolio management and risk transfer decisions.”

AIR said its model has been validated against more than $6 billion in claims data from client companies for recent hurricanes and more than $10 billion from AIR’s parent and sister companies. The validation also uses detailed insurance company claims data and industry-level losses from ISO Property Claim Services collected over the past two decades.

The AIR Hurricane Model for the U.S. is available in the Touchstone 3.0 and CATRADER 17 catastrophe risk management systems.

Source: AIR Worldwide