IBHS News Releases

Tampa - With the 2006 hurricane season underway and recovery from last year’s devastating season continuing, new research suggests there may be improved methods of estimating risk that would go a long way to better protecting people and their property from hurricanes.

The Institute for Business & Home Safety’s (IBHS) “Hurricane Katrina Study and Assessment” findings also reinforce the need in high wind areas for the adoption and enforcement of modern building codes and standards where they don’t exist, along with related training for builders, building officials and others in the construction field.

In the aftermath of the widespread damage caused by Hurricane Katrina, IBHS coordinated a field assessment of wind damage to residential buildings in areas from coastal Mississippi to Hattiesburg and along coastal areas of Louisiana.

Wind speed measurements and wind field modeling done by public and private sources indicated maximum winds throughout the area of impact that were substantially below the Saffir-Simpson (SS) Category 4 and 5 conditions reported when the storm was over the Gulf of Mexico. Yet Hurricane Katrina produced SS Category 5 surge along extensive stretches of the Mississippi coast. The surge was higher in some areas than that reported for the portions of the coast hardest hit by SS Category 5 Hurricane Camille in 1969.

In fact, actual storm surge levels were well above the flood elevations estimated by historical data for the region, in some cases by as much as 12 feet.   

IBHS wanted to know answers to questions like: If current hurricane simulation programs, which accurately model wind fields and their variations over time, could also accurately model surge and wave levels at landfall. And, if so, is it possible to begin estimating risks of surge, inundation levels and waves using simulation programs that reflect historical tendencies. Finally, would those predictions provide better guidance for residential and commercial construction development in these vulnerable coastal regions?

To find answers to those questions and to provide accurate estimates of Katrina’s wind speeds, storm surge and wave effect, IBHS contracted Applied Research Associates (ARA) to conduct a detailed model study of the hurricane. The study found: 

• State-of-the-art hurricane wind field and storm surge modeling can produce credible estimates of both wind speeds and storm surge from an integrated simulation.  
• Major SS Category storm surge heights can be produced by winds from lesser category land-falling storms. For surge, the life cycle of the storm as it approaches land is more important than the actual wind speeds at landfall.    
• Most of the affected areas experienced gust wind speeds below those established by conventional standards for high-wind exposed areas. In fact, most of the wind damage to structures built after 1995 could have been prevented had the jurisdictions adopted and actively enforced model building codes and high wind construction guideline documents available in the early 1990s.

According to Dr. Timothy Reinhold, IBHS vice president of engineering, “In addition to identifying building code and training needs, these findings tell us that the use of historical data alone is likely to be inadequate for providing reliable risk-based decisions on elevation requirements. Instead, we should establish these requirements based on simulation programs that model historical tendencies in storm parameters and tracks. This will give us more accurate risk-based estimates of surge and wave heights.”

The Institute for Business & Home Safety is a national nonprofit initiative of the insurance industry. Its mission is to reduce the social and economic effects of natural disasters and other property losses by conducting research and advocating improved construction, maintenance and preparation practices.

To read an overview of the "Hurricane Katrina Study and Assessment," click here.