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Boussinesq modeling of wave‐induced hydrodynamics in coastal wetlands
Author(s) -
Chakrabarti Agnimitro,
Brandt Steven R.,
Chen Qin,
Shi Fengyan
Publication year - 2017
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1002/2016jc012093
Subject(s) - drag coefficient , wave height , drag , nonlinear system , attenuation , quadratic equation , wave model , storm , vegetation (pathology) , mechanics , meteorology , physics , mathematics , geometry , optics , medicine , pathology , quantum mechanics , thermodynamics
In this paper, an improved formulation of the vegetation drag force, applicable for the fully nonlinear Boussinesq equations and based on the use of the depth‐varying, higher‐order expansion of the horizontal velocity, in the quadratic vegetation drag law has been presented. The model uses the same numerical schemes as FUNWAVE TVD but is based on the CACTUS framework. The model is validated for wave height and setup, against laboratory experiments with and without vegetation cover. The wave attenuation results using the improved formulation were compared with those using the first‐order reference velocity as well as with analytical solutions using linear wave theory. The analytical solution using the depth‐varying velocity, predicted by the linear wave theory, was shown to match the model results with the fully expanded velocity approach very well for all wave cases, except under near‐emergent and emergent conditions (when the ratio of stem height to water depth is greater than 0.75) and when the Ursell (Ur) number is less than 5. Simulations during peak storm waves, during Hurricane Isaac, showed that vegetation is very effective in reducing setup on platforms and in reducing the wave energy within the first few hundred meters.