Field measurements and model predictions of turbulent kinetic energy in canopies of sparse vegetation under tidal flows

Abstract The presence of vegetation in aquatic environments alters hydrodynamics and sediment resuspension. A recent paradigm has suggested that turbulent kinetic energy (TKE) serves as a better predictor of sediment transport in aquatic canopies than bed shear stress. This observation has led to the development of formulations to predict TKE for vegetated flows in the laboratory. However, model validation from natural heterogeneous field environments is lacking. Here, we explore the application of laboratory‐based formulas in a real environment, characterized by multiple vegetation length scales. We measured turbulence within a sparse canopy of mangrove pneumatophores and saplings during an experimental period with negligible wind‐wave activity. The existing formulations for TKE performed well in the field, but only when using the measured values for horizontal eddy length scales. These length scales accounted for the generation of additional turbulence from the surrounding sapling canopy, leading to notably larger TKE values than in similar laboratory experiments.