MODELING MORPHOLOGIC RESPONSES TO PROPOSED ENGINEERING MODIFICATIONS AT SEBASTIAN INLET, FL

Numerical simulations of hydrodynamics and sediment transport were conducted for Sebastian Inlet, FL, using the Coastal Modeling System (CMS). The study is aimed at determining changes in morphology under the existing topography and configuration as compared with two proposed modification scenarios: 1) an extension of the south jetty and 2) dredging of the outer section of the ebb shoal. The analysis time period encompasses short term (storm vents), as well as long term (seasonal). Overall, the predicted morphology changes were in good agreement with measured data. Model calculations of littoral sand transport under the existing configuration indicated an overall sand transport to the south over the long term, as well as reversal approximately 2km south of the inlet. The model also successfully reproduced the variability in littoral transport due to the different storms, especially the reversal in the drift direction.