Improved wave transformation in a large-scale coastline model to explore the role of wave climate change in driving coastal erosion

According to the 2010 U.S. Census, over one third of the United States population lives near the eastern coastline. With such a significant investment in human agency along the coast, it is critical to understand how large-scale coastal morphology will evolve in the coming decades in response to rising sea level and changing storm climates. Previous work has shown that potential changes in wave climate can give rise to a larger coastal erosion signal than that expected due to sea level rise alone. This work utilized a large-scale coastal change model that simulated deep-water wave transformation assuming bathymetric contours were parallel to the shoreline and the model did not incorporate wave crest convergence or divergence. Linear stability analyses that have been performed on large-scale coastline evolution that do not assume parallel bathymetric contours and account for wave converge and divergence were found to be sensitive to the offshore extent of shore parallel contours. This study incorporates wave ray tracing into an existing coastline change model to explore finite amplitude development and evolution of large-scale coastal morphology. We will present results that explore the relative contributions of wave climate change and sea level rise to coastal erosion.