The main objective of this paper is to analyze the influence of roughness caused by coastal vegetation, in particular submerged stiff vegetation, on the wave boundary layer.

Laboratory experiments have been performed in an oscillating water tunnel, covering a range of frequencies ω=0.698−3.927 s−1https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429206122/0f389fca-913b-4aa6-9124-91e40346270b/content/eq649.tif"/>. Velocities were measured using a 2D Particle Image Velocimetry (PIV) system. Vegetation was modeled by rigid cylinders of constant diameter d. A dataset of phase average velocity profiles have been analyzed. Disturbed laminar and intermittently turbulent regimes were investigated.

The analysis of velocity profiles have shown that vegetation induces modifications of the WBL, causing a reduction of the phase average velocity respect to the no-vegetated bottom case, confirming the expectation, namely the influence of vegetation on the boundary layer properties.