Inclusion of additional energy dissipation due to plunging breakers in parametric type wave models

• Field and lab data show importance of energy dissipation due to plunging breakers.
• Data reveals shortcomings of parametric models based solely on bore dissipation.
• Empirical formulations are derived and included in parametric wave model.
• Significant improvements in model-data comparisons are found.

One of the most critical issues in coastal engineering problems is to accurately predict the wave height profile across the surfzone. Parametric wave models are broadly used in modelling the wave energy dissipation in this regard. Three parametric wave models based on the bore energy dissipation model were evaluated against new field measurements under various conditions from mild to stormy. The results indicate that a discrepancy between models and data occurred near the break point for cases where the wave breaking was of the plunging type but after the breakpoint the wave height decay rates compared well. In order to improve this model shortcoming, comprehensive new laboratory tests were conducted to quantify the additional energy dissipation due to plunging breakers. Based on the data, new empirical equations were derived and incorporated into the most recent bore dissipation parametric wave model. The inclusion of the extra energy dissipation due to plunging breakers results in significant improvement in the prediction of the wave height profile.