15 Oct 2025

An Investigation into the Correlation Between Selected Coastal Protection Indices and Percent Residual Dune and Berm Volumes Following Coastal Storms

Abstract: Morphometric indices describe the dimensions of a dune and berm profile and can serve as relative metrics of coastal protection. However, coastal vulnerability to storm damage also depends on storm, wave, sediment, and offshore characteristics. Recently, more elaborate non-morphometric indices have been proposed in an effort to account for these other factors. This study compares the correlation between these morphometric and non-morphometric indices and one measure of coastal protection, the ability of a dune and berm profile to resist storm-induced changes in volume. This study uses a numerical-simulation approach rather than an empirical approach because a sufficiently comprehensive set of observational data does not exist. A randomized sample of dune and berm profiles were generated at eight coastal locations. Using the cross-shore numerical model (CSHORE), storm-induced changes in dune and berm volume were simulated for storms of low to moderate severity. The correlation between the various prestorm indices and the percentage of prestorm dune and berm volume remaining after the storm was calculated at each location. Results show that no single index always exhibits a higher correlation with percent dune and berm volume remaining. However, some indices were far more likely than others to produce higher correlations.