Modeling Sediment Tracers to Evaluate Current and Sediment Plume at Beaufort Inlet, North Carolina

A coastal wave, hydrodynamic, and sediment transport model, the coastal modeling system (CMS), is developed to conduct sediment tracer simulations and investigate the distribution of sediment plumes that originated from dredged material placement sites adjacent to Beaufort Inlet, North Carolina. Historical wave and hydrodynamic data around the inlet are assembled and analyzed. The data sets are used to drive the model. Simulation alternatives are developed that correspond to different material placement sites. The sediment transport and plume distribution are evaluated within and around the immediate vicinity of the Beaufort Inlet estuarine system for representative summer and winter months. The results of the model simulations show that high flows occur along the navigation channels and low flows occur outside the inlet in the open ocean area. Sand materials placed in nearshore sites tend to be trapped in and move along the navigation channels that enter the inlet. In offshore placement sites, the sediment plume shows slow spreading and no significant sand migration from its release locations. Simulations for the summer and winter months present different distribution patterns of sediments from the nearshore and offshore placement sites but show similar distribution patterns for each placement site.