Quantifying the influence of profile variability on dune impacts during Hurricane Sandy

Abstract

Hurricane Sandy was undoubtedly one of the most impactful storms of the past half century, resulting in $74 billion of damage and destroying thousands of homes. Yet not all communities suffered the same. In New Jersey, impacts exhibited mesoscale trends with northern portions of the state generally suffering greater damage than the southern portions. Mantoloking experienced widespread major damage; however, less than 5 km away, Point Pleasant escaped with significantly less damage. The disparate outcomes are associated with vastly different berm widths and dune volumes, with Point Pleasant protected by wider, more resilient beaches. Here, a recently developed dune vulnerability model is used to quantify differences in vulnerability resulting from spatial variations in storm intensity and pre-storm morphology for beaches along the New Jersey coastline. Spatial analysis of pre-Sandy beach conditions exhibits trends in vulnerability, which align with observed impacts. The vulnerability analysis accounts for gradients in storm intensity, dune volume, and berm width. Comparison of different outcomes while isolating for a single variable (e.g. intensity, volume or width) suggests the vulnerability model is robust and can quantify temporal vulnerability due to changes in beach state. For example, the results suggest Point Pleasant Beach would have been four times as likely to suffer major impacts had Sandy occurred with beach conditions observed in 1995.