Forecasting Changes in the Hurricane Wind Vulnerability of a Regional Inventory of Wood-Frame Houses

Abstract

Current regional hurricane loss estimation models use the present-day vulnerability of the building inventory in predicting future losses and assume that it remains static throughout the time horizon of interest. In reality, the hurricane vulnerability of a region changes with time due to changes in the types and conditions of buildings. Loss estimation models, therefore, may misestimate risk and the effectiveness of mitigation plans based on these loss estimates may be compromised. In this paper, the writers develop a regional vulnerability change model to estimate changes over time in the hurricane wind vulnerability of a regional inventory of wood-frame houses. The model integrates the effects of five types of changes—changing building codes, changing technologies, building demolition and construction, structural aging, and upgrading efforts—in a simulation framework to forecast changes in the vulnerability of a region. Projectile impacts, falling trees, and flooding are not considered currently. A case study application of the model was conducted for one-story, gable roof, wood buildings in New Hanover County, N.C., for the period 2000–2020. Results describe the estimated overall change in the hurricane wind vulnerability, the relative contributions of the five types of change, a sensitivity analysis, and the long-term effects of a hypothetical “what-if” mitigation scenario on the evolution of regional vulnerability.