Print Email Facebook Twitter Net sediment transport in tidal basins: quantifying the tidal barotropic mechanisms in a unified framework Title Net sediment transport in tidal basins: quantifying the tidal barotropic mechanisms in a unified framework Author Gatto, V.M. (TU Delft Coastal Engineering) van Prooijen, Bram (TU Delft Environmental Fluid Mechanics) Wang, Zhengbing (TU Delft Coastal Engineering) Date 2017 Abstract Net sediment transport in tidal basins is a subtle imbalance between large fluxes produced by the flood/ebb alternation. The imbalance arises from several mechanisms of suspended transport. Lag effects and tidal asymmetries are regarded as dominant, but defined in different frames of reference (Lagrangian and Eulerian, respectively). A quantitative ranking of their effectiveness is therefore missing. Furthermore, although wind waves are recognized as crucial for tidal flats’ morphodynamics, a systematic analysis of the interaction with tidal mechanisms has not been carried out so far. We review the tide-induced barotropic mechanisms and discuss the shortcomings of their current classification for numericalprocess-based models. Hence, we conceive a unified Eulerian framework accounting for wave-induced resuspension. A new methodology is proposed to decompose the sediment fluxes accordingly, which is applicable without needing (semi-) analytical approximations. The approach is tested with a one-dimensional model of the Vlie basin, Wadden Sea (The Netherlands). Results show that lag-driven transport is dominant for the finer fractions (silt and mud). In absence of waves, net sediment fluxes are landward and spatial (advective) lag effects are dominant. In presence of waves, sediment can be exported from the tidal flats and temporal (local) lag effects are dominant. Conversely, sand transport is dominated by the asymmetry of peak ebb/flood velocities. We show that the direction of lag-driven transport can be estimated by the gradient of hydrodynamic energy. In agreement with previous studies, our results support the conceptualization of tidal flats’ equilibrium as a simplified balance between tidal mechanisms and wave resuspension. Subject Wadden SeaSettling lagTidal asymmetryResidual transportTidal basinsMorphodynamics To reference this document use: http://resolver.tudelft.nl/uuid:5c00582e-6a20-4e70-8f8e-992d3fbd8076 DOI 10.1007_s10236-017-1099-3 ISSN 1616-7341 Source Ocean Dynamics: theoretical, computational oceanography and monitoring Part of collection Institutional Repository Document type journal article Rights © 2017 V.M. Gatto, Bram van Prooijen, Zhengbing Wang Files PDF Gatto_10.1007_s10236_017_1099_3.pdf 3.73 MB Close viewer /islandora/object/uuid:5c00582e-6a20-4e70-8f8e-992d3fbd8076/datastream/OBJ/view