Numerical Simulation of Shoreline Change at Lorain, Ohio

Abstract

Design of detached breakwaters for shore protection is difficult because the response of the shoreline to these structures is governed by at least 14 geometric‐, wave‐, and sediment‐related variables. Numerical models of shoreline change have the potential of incorporating these variables to predict the time evolution of the beach plan shape; however, wave transmission at breakwaters has been a major process absent from such models. In this paper, a pragmatic method of calculating the breaking‐wave height and angle under combined transmission, diffraction, refraction, and shoaling is tested to predict shoreline change measured at Lorain, Ohio, the site of a three‐segment transmissive breakwater system. The model successfully simulated observed shoreline change at the site that occurred over three time periods ranging from one to five years. Model sensitivity to changes in key parameters and simulations of alternative shore‐protection designs to the Lorain project are also described.