Evaluation of Two Spectral Wave Models in Coastal Areas

ABSTRACT Gonçalves, M.; Rusu, E., and Guedes Soares, C., 2015. Evaluation of two spectral wave models in coastal areas. The objective of the present work is to evaluate two wave models, SWAN and STWAVE, considering various coastal areas with different bathymetric features. Although both models are based on the spectrum concept and integrate the action balance equation over the computational domain using rectangular grids, there are also fundamental differences between them induced by the propagation schemes implemented and also by the different formulations considered for the basic source terms. The two models are evaluated in four coastal areas, three of them belonging to the Portuguese continental coastal environment and the other one located in the nearshore of Sardinia Island. The bathymetric characteristics of the computational domains considered are rather different. Two of them have smooth contours, another is characterized by very high bathymetric gradients, and finally the last one includes a harbor area. Comparisons of the models' predictions against measurements were carried out in both intermediate and very shallow water. Besides these, comparisons between the two models as regards the field distributions of the main wave parameters were also performed. The results of the work show that SWAN is a more complex model that can be better calibrated and adapted for a specific site, especially due to the multitude of options available. On the other hand, STWAVE is simpler, more robust, and quicker and can be used effectively in various coastal environments.

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