Wave Climate and Littoral Sediment Transport Potential, Cape Fear River Entrance and Smith Island to Ocean Isle Beach, North Carolina

Abstract

Abstract : Numerical model studies were conducted to assist the U.S. Army Engineer District, Wilmington, in evaluating potential plans for modifying the Cape Fear River entrance channel and in preparing General Reevaluation Reports. The offshore wave climate was evaluated, and Wave Information Studies hindcasts from 1976-1995 were used as the incident wave climate. Wave transformation around Frying Pan Shoals and nearshore bathymetry were modeled with the spectral wave model STWAVE. Wave climate was estimated in existing and plan navigation channels and along the Brunswick County, North Carolina, coast west of Cape Fear. Since potential areas for offshore disposal of dredged material are included in the wave model coverage, wave climate in the finally selected offshore dredged material site can be estimated from study results as needed. Nearshore wave climate and littoral transport were estimated for existing conditions between Cape Fear and the middle of Ocean Isle Beach to the west. Other bathymetric conditions studied in the more localized area between Cape Fear and the middle of Long Beach are historical 1872 bathymetry, a plan navigation channel, and the plan channel with adjusted ebb-tide shoals representing a long-term equilibrium with the relocated channel. Potential longshore annual transport rates were computed at approximately 55-m (180-ft) intervals along these coasts.