Impacts of hard structures on the evolution of sandy shorelines.

Activity: Talk or presentationOral presentation


Co-authored with Ian Shennan, Richard Hardy, and Laura Turnbull-Lloyd

Hard structures are common for managing sandy shorelines. While hard structures reduce wave energy and facilitate sediment accumulation, they can cause sediment removal elsewhere through wave energy refraction. Despite their knock-on effects, hard engineering remains popular for managing sandy shorelines, often due to a limited understanding of the long-term interactions between hard structures and coastal processes. Therefore, this paper evaluates the impact of hard structures on the evolution of sandy shorelines on annual and decadal timescales. We consider two locations, both managed sandy shorelines, in New York and Southern California. We use coastal relief and processes data from NOAA, and site characteristics from aerial photographs to develop a two-dimensional coupled wave, flow, and sediment transport model referenced to mean high water, with and without hard structures. These provide the basis, at both sites, to simulate shoreline change using the MIKE 21 Coupled Model for a 20-year period. We calibrate and verify the models against observations of currents and shoreline morphology, and quantify the annual and decadal impact of hard structures on predicted sediment transport rates and bed level changes. From these, we identify the short and long-term impact of hard structures on sandy shoreline evolution, to better support decision making in coastal management.
Period22 Oct 2018
Event titleLittoral 2018
Event typeConference
LocationLeeuwarden, Netherlands