The interacting effects of storm surge intensification and sea-level rise on coastal resiliency: a high-resolution turbulence resolving case study

Abstract

Climate change and global warming will increase the risk of coastal floods and storm surges, which can highly jeopardize communities and infrastructures along shorelines. There are two main drivers for this increase: surge amplification, which is caused by the projected hurricane intensification, and global sea-level rise (SLR). Although both factors can simultaneously affect storm surges, current knowledge on their interacting effects on the resiliency of coastal infrastructure is limited. To address this knowledge gap, we investigate the impacts of multiple storm surge scenarios on vehicles and buildings by varying wave heights, periods, and sea levels under current mitigation strategies. These surges are highly turbulent due to their high speed and wave-wave/bathymetry interactions. Large-scale numerical simulations with low-resolution (∼1–5 km) and depth-integrated models that do not resolve turbulence cannot assess the thorough impacts of these storm surges on infrastructures accurately. Hence, we employ a high-resolution numerical approach that is capable of resolving turbulent eddies down to ∼3 cm and capturing fluid-structure interactions. The distribution of hydrodynamic loads is found to vary nonlinearly in all directions with surge amplification and can significantly exceed calculations from classical theories that neglect turbulence. Two approaches from previous experiments are employed in a novel way to evaluate the resiliency of vehicles and infrastructure during storm surges. Our results indicate that vehicle mobility on the considered road will be imperiled by moderate surges (4 m wave height), and the elevated building will fail by surge intensification (8 m waves). We found that some storm-surge wave heights that are relatively safe now (e.g., 2 m waves for vehicles and 6 m for the building) will become hazardous in the future with an SLR. Therefore, road and building safety regulations should account for the interacting effects of hurricane intensification and SLR when devising mitigation strategies.