A Multi-Hazard Model for Coastal Damages in the United States

Abstract

Although hurricanes regularly devastate swathes of built-up environment along the coasts of the United States, it is difficult to predict the toll that a hurricane can have on a region because of the many variables that factor into the damage they cause. Previous studies have taken an event-by-event approach, forecasting total damages related to a storm. Models created using this technique predict storm damage as a function of storm parameters (i.e., maximum windspeed, speed of storm, or atmospheric pressure). Although varying subsets of storm parameters have been investigated, there has yet to be a model that considers the combined impact of hazards—in this case rainfall levels, storm surge heights, and windspeed—on reported damage. Two decades of county-level damage from the continental United States and hazard data taken from the years 2001-2020 form the basis of this geographical model, where an equation adapted from previous studies on multi-hazard events is used to solve for coefficients. A model of coastal counties predicts damage as a function of hazard levels, and demonstrates a positive correlation between the intensity of three storm hazards and damage for a region. Subsets of data representing smaller regions along the coast are also modelled, with resulting plots demonstrating significantly better fits based on location, and a smaller relevant region. While the model tends to overestimate damage in low-damage cases and underestimate damage in high-damage cases, it succeeds in introducing a multi-hazard approach as a viable option for hurricane damage forecasting.