Impacts of sea level rise on future storm-induced coastal inundations over massachusetts coast

Abstract

Hurricanes (tropical cyclones) and nor'easters (extratropical cyclones) are two major storm systems for flood risk over the Massachusetts coast. Severe coastal inundation usually happens when wind-induced waves and storm surges coincide with high tides. A Northeast Coastal Ocean Forecast System (NECOFS) was established and placed into the 24/7 forecast operations starting in 2007. Using a well-validated “end to end” FVCOM inundation model of NECOFS, we examined the impact of climate change-induced sea-level rise (SLR) on the future extratropical storms-induced coastal inundation over the Massachusetts coast. The assessment was done by making the model experiments to project the storm-induced inundation over the coastal areas of Scituate and Boston Harbors with different SLR scenarios under a hundred-year storm condition. The results suggest that with sustained SLR, the northeastern US coast will be vulnerable more severely to wave runup-induced splashing/overtopping than wind-induced storm surges. This finding is consistent with the change in the intensity of storm-generated surface waves in the last decade. The model also suggests that the responses of surge and surface waves to SLR are fully nonlinear. The assessment of the impacts of SLR on the future storm-induced coastal inundation should be investigated with a model including wave-current interactions.