Improving Input Wave Data for Use with Shoreline Change Models

Shoreline change models such as GENESIS use refracted wave data identified at nearshore water depths that are seaward of the breaking limit for the largest waves in the model's ensemble. Adjustment of the manner in which wave data are input to the model can potentially improve the physical reality of the model's predictions. This paper presents a method whereby incipient breaking wave conditions are computed for each refracted wave case and then transformed offshore to a given reference water depth for subsequent input to the shoreline change model. This allows for consideration of wave transformations that occur between the reference water depth and the point of incipient breaking. This adjustment is shown to be of particular importance in those cases where the nearshore bathymetry is irregular.