EFFECTS OF BATHYMETRIC COMPLEXITIES AND WIND GENERATION IN A COASTAL WAVE-PROPAGATION MODEL

A new wave modelling strategy has been developed by Holthuijsen et al. ( 1989) for estimating wave heights for engineering applications in c oastal areas, This strategy as well as the original model itself of Ho lthuijsen et al. (1989), called HISWA, are being used in several engin eering applications. This paper examines two aspects of this model: it s ability to adequately predict wave properties in regions with comple x bathymetry where diffraction effects are likely to be important, and its ability to model wave growth due to wind, The former is of intere st because the model is based on the energy-balance equation and does not explicitly incorporate diffraction. Other such models deal with th is through artificial bounds on the energy, whereas HISWA does not. It is therefore necessary for the engineer to be aware of its performanc e in such situations. Investigations are therefore performed using hyd raulic model data and the results of other mathematical models that ar e known to adequately handle such bathymetric configurations. For comp lex bathymetries, the model is found to give good simulations for sea- states with considerable directional spreading. As the degree of sprea ding decreased or for certain special wave conditions, model performan ce was marginal. Finally, the model is used to study the physics of wa ve decay and wind-induced growth in Saginaw Bay (Michigan) using proto type data.