Frictional wave dissipation in macro-roughness environments: A comparison of bottom stress and bulk canopy drag models

Abstract

Friction dissipation induced by the seabed is a key factor for wave attenuation in nearshore environments presenting large roughness structures, such as rocky or coral shores. Two seminal models are classically used to predict bottom friction dissipation: the bottom stress (BS) and bulk canopy drag (BCD) models. Aiming to compare the performances of both models in controlled laboratory conditions, the present paper reanalyses the wave dissipation data provided by Dealbera et al., (2024). An approach to calculate the frontal transverse area based on real terrain consideration is suggested. The hydraulic parameter and the drag coefficient are optimized from the experimental data using several approaches and model parameterizations. Performance estimators of each model parameterization are compared and reveal a more robust predictive performance of the BCD model. The BS model could be improved by changing the vertical reference of the estimated flow velocity.