| |
Sandy coasts are dynamic environments that respond to changes in wave climate and storm events. Coastal changes effect widespread impacts due to the density of human populations and diverse ecosystems characteristic to coastal zones. Accordingly, understanding the influence of wave and storm climates on coastal morphology is critical to the management of natural resources and municipal interests, one of which being freshwater supply to coastal communities. This study employs the Coastline Evolution Model, a one-contour-line, two-dimensional numerical coastal evolution model, to explore the morphologic response of sandy coasts to various wave climates at annual, decadal, and centennial timescales. In our model, coastline evolution is driven by gradients in longshore sediment transport, which produce regions of erosion and regions of deposition. The volume and direction of sediment transport in this model is parameterized by wave heights and direction. Recent studies indicate that regional trends in wave height and approach direction are shifting, perhaps, as a result of global climate change. Numerical simulations presented here utilize predicted wave conditions to demonstrate how the stability of a coastal planform may be impacted by persistent changes in nearshore wave conditions. In addition to decadal wave-driven morphologic trends, sandy coasts responds to energetic storms such as hurricanes and nor’easters; analyses indicated that observed shifts in global climate may lead to an increase in frequency and intensity of storm events. This study quantifies variability in the magnitude of shoreline change as a result of recurrent high-intensity storms and analyzes the influence of storm-related offshore sediment transport on the propensity of a coastline to form cuspate features. The growth or loss of these features influences the distribution of coastal biota and is an important consideration in coastal engineering and development. |
