AIR Worldwide Releases Inland Flood Model for the United States

BOSTON, Oct. 6, 2014 — Catastrophe risk modeling firm AIR Worldwide (AIR) today announced that it has released a detailed, physically based, probabilistic inland flood model for the United States. The new model will provide insurers and other industry stakeholders with a comprehensive tool for assessing and managing inland flood risk at a high resolution for locations on and off the many and varied floodplains across the United States. AIR is a Verisk Analytics (Nasdaq:VRSK) business.

“Until now, the industry has lacked the tools to effectively quantify flood risk in the United States,” said Dr. Jayanta Guin, executive vice president, AIR Worldwide. “We’re excited to bring this game-changing modeling solution to market. It’s a major step forward in helping the industry manage this complex risk by better understanding the severity, frequency, and location of potential flood events.”

The applications of flood modeling technology are far-reaching and span the entire insurance value chain. Benefits for insurers may include a more robust view of individual risk pricing sensitivity and new opportunities for flood insurance product innovation. Risk managers can also better identify the assets driving their overall risk and help develop and design cost-effective risk transfer strategies to manage that risk.

The AIR Inland Flood Model for the United States defines flood events based on a physical understanding of what causes flooding and how floods propagate through the country’s extensive river networks. The model captures inland flood risk for all 18 hydrological regions across the contiguous United States, an area of approximately 3 million square miles with a river network 1.4 million miles long, including 335,000 distinct drainage catchments.

The model simulates both the weather systems and the flooding they cause and accounts for a broad range of climatic conditions, snowmelt, local soil conditions, land use, and topography. Simulated flood propagation accounts for the effects of more than 20,000 lakes and reservoirs. Damage is determined by calculating the inundation depth at each affected location, taking into account the country’s extensive system of levees and their probability of failure, as well as regional differences in building codes and building practices.

In addition to accounting for flooding that will occur next to the river, AIR also incorporates flood hazard that can happen away from the river, known as off-floodplain flooding. This can happen because of factors such as particularly intense rainfall and poor drainage, among other factors.

AIR’s innovative approach to simulating rainfall couples a global Community Atmospheric Model (CAM) with a regional Weather, Research, and Forecasting (WRF) model. The results are realistic and statistically robust storm patterns over space and time. A sophisticated downscaling technique enables the model to capture both large- and small-scale precipitation patterns, including the bursts of extreme rainfall that contribute greatly to highly localized flooding.

The AIR model also uses a physically based hydraulic model that calculates the extent of flooding and the depth of inundation at each location of interest on the floodplain. This unique hydraulic model accurately accounts for local terrain characteristics and generates a physically consistent delineation of floodwater extents.

Additionally, FEMA is currently undertaking a “Flood Insurance Risk Study” project, which AIR is proud to be participating in. FEMA is looking to assess the potential of the private sector, including insurers, reinsurers, and capital markets, to take on portions of the flood risk. Fundamental to the study is AIR’s probabilistic U.S. inland flood model, the only model of its kind.

“The AIR Inland Flood Model for the United States represents one of the most challenging and innovative research development efforts in AIR’s history,” continued Dr. Guin. “This state-of-the-art model accounts for the unique circumstances that contribute to flood risk across the country. It provides insurers with a highly detailed, physically based, probabilistic approach for underwriting and helping to manage this complex risk on and off the floodplain and for uncovering new opportunities in the evolving flood insurance market.”

The AIR Inland Flood Model for the United States is currently available for Version 2.0 of the Touchstone® and Version 16 of the CATRADER® catastrophe risk management systems.

About AIR Worldwide
AIR Worldwide (AIR) is the scientific leader and most respected provider of risk modeling software and consulting services. AIR founded the catastrophe modeling industry in 1987 and today models the risk from natural catastrophes and terrorism in more than 90 countries. More than 400 insurance, reinsurance, financial, corporate, and government clients rely on AIR software and services for catastrophe risk management, insurance-linked securities, detailed site-specific wind and seismic engineering analyses, and agricultural risk management. AIR, a Verisk Analytics (Nasdaq:VRSK) business, is headquartered in Boston with additional offices in North America, Europe, and Asia. For more information, please visit


Kevin Long
AIR Worldwide

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