(NASA satellite image of Hurricane Claudette of 2003.)
AIR Worldwide (Boston) has made what it calls a comprehensive update to its Hurricane Model for the United States, which the vendor says features a new, fully hydrodynamic storm surge module that integrates storm parameters with high-resolution elevation data to simulate location-specific storm surge inundation depth and extent.
“Hurricane storm surge can be devastating, resulting in substantial damage and high insured losses,” comments Tim Doggett, Ph.D., assistant VP and senior principal scientist, AIR Worldwide. “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. AIR’s new hydrodynamic storm surge module for the U.S. hurricane model represents state-of-the-art modeling techniques and the latest research on storm surge hazard to accurately assess risk at very high resolution.”
AIR notes that storm surge results from a combination of variables, including storm size, strength, speed, and path, as well as tidal heights and coastal geography. The company’s updated storm surge module incorporates the 30-meter National Elevation Dataset (NED) developed by the USGS, which AIR notes is the same data set used in the AIR Inland Flood Model for the United States. The module also leverages a highly customized and optimized variation of NOAA’s well-established Sea, Lake, and Overland Surges from Hurricanes (SLOSH) model for use with the AIR model. The new storm surge module incorporates regional and seasonal data on tide heights and contains the most 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 AIR.
The model updates also include the most recent North Atlantic hurricane database (HURDAT2) from NOAA, the latest reanalysis data from 1930 to 1945, and the 2011 release of the USGS National Land Cover Database (NLCD 2011), AIR reports. The vendor adds that 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 leverage information on primary building characteristics (such as construction, occupancy, and height) and a host of secondary characteristics (including base flood elevation, foundation type, number of basement levels, floor of interest, and custom flood protection), which can be entered by the model user, AIR says. The model estimates physical damage and time-element losses using damage functions that reflect local building codes and regional design practices, as well as damage survey findings, claims analyses, and engineering research, the vendor says.
“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,” Doggett adds. “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’s says that its U.S. Hurricane 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 carrier claims data and industry-level losses from ISO Property Claim Services collected over the past two decades, according to AIR.
The AIR Hurricane Model for the United States is available in the vendor’s Touchstone 3.0 and CATRADER 17 catastrophe risk management systems.