A Wave Prediction Model in Reef Coasts

摘要

A wave prediction model is presented based on the finite element method. solving the one-dimensional open boundary problems. Usefullness of the model has firstly been investigated in comparison with the theoretical wave height distributions for four bathymetries and experimental results for waves on a step-type reef, where the boundary conditions can clearly been defined. The result is that wave heights can be predicted with actual accuracy, even when bathymetry changes discontinuously; an example is the dredged sea bed.Secondly, it has experimentally been verified that evaluation of irregular wave spectra based on the theory of linear systems is available. However, the frequency response (FR) of the bathymetry to waves is necessary to be known, and then the present model is useful in estimating FR.It is clear that the same treatment is possible in the two-dimensional space for which the model similar with the present one was offered previously (Tsutsui, 1989). Therefore, we are now able to handle the regular and irregular waves in Okinawan reef coasts, in terms of the one-and two-dimensional wave prediction models.