Author(s): Masaya Yoshikai; Julia Mullarney; Vinay Nelli; Remi Chassagne; William Nardin; Rafael Tinoco
Linked Author(s): Julia Mullarney, Rafael Tinoco, William Nardin
Keywords: Coastal vegetation turbulence vegetation patch field measurement
Abstract: Coastal vegetation often grows in spatially distributed patches. However, detailed measurements of mean and turbulent flows accounting for such spatial heterogeneity are rare. We present measurements from manipulative experiments in the field by creating artificial patches of vegetation mimics with varied vegetation density and height. We found that: (1) an increase in vegetation density substantially reduces flow velocity and turbulent kinetic energy (TKE) within a patch, and (2) an increase in vegetation height induced a contrasting effect, causing faster flows and greater TKE within the patch, especially for a dense patch. The same trend was obtained in numerical hydrodynamic simulations. Elevated TKE was observed behind dense vegetation patches, due to large-scale turbulence created by Kelvin-Helmholtz instability, compared to lower TKE behind sparser patches. These results suggest that vegetation height and density create diverse spatial patterns in TKE around patches, while inducing contrasting effects on flow and turbulence within patches.
Year: 2025