Tidal asymmetry and residual circulation over linear sandbanks and their implication on sediment transport : a process-oriented numerical study
MetadataShow full item record
A series of process-oriented numerical simulations is carried out in order to evaluate the relative role of locally generated residual flow and overtides on net sediment transport over linear sandbanks. The idealized bathymetry and forcing are similar to those present in the Norfolk Sandbanks, North Sea. The importance of bottom drag parameterization and bank orientation with respect to the ambient flow is examined in terms of residual flow and overtide generation, and subsequent sediment transport implications are discussed. The results show that although the magnitudes of residual flow and overtides are sensitive to bottom roughness parameterization and bank orientation, the magnitude of the generated residual flow is always larger than that of the locally generated overtides. Also, net sediment transport is always dominated by the nonlinear interaction of the residual flow and the semidiurnal tidal currents, although cross-bank sediment transport can occur even in the absence of a cross-shore residual flow. On the other hand, net sediment divergence/convergence increases as the bottom drag decreases and as bank orientation increases. The sediment erosion/deposition is not symmetric about the crest of the bank, suggesting that originally symmetric banks would have the tendency to become asymmetric.
Author Posting. © American Geophysical Union, 2007. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 112 (2007): C12015, doi:10.1029/2007JC004101.
Suggested CitationJournal of Geophysical Research 112 (2007): C12015
Showing items related by title, author, creator and subject.
Burchard, Hans; Schuttelaars, Henk M.; Geyer, W. Rockwell (American Meteorological Society, 2013-09)In this idealized numerical modeling study, the composition of residual sediment fluxes in energetic (e.g., weakly or periodically stratified) tidal estuaries is investigated by means of one-dimensional water column models, ...
Seagrass impact on sediment exchange between tidal flats and salt marsh, and the sediment budget of shallow bays Donatelli, Carmine; Ganju, Neil K.; Fagherazzi, Sergio; Leonardi, Nicoletta (John Wiley & Sons, 2018-05-20)Seagrasses are marine flowering plants that strongly impact their physical and biological surroundings and are therefore frequently referred to as ecological engineers. The effect of seagrasses on coastal bay resilience ...
Sediment delivery to a tidal marsh platform is minimized by source decoupling and flux convergence Coleman, Daniel J.; Ganju, Neil K.; Kirwan, Matthew L. (American Geophysical Union, 2020-06-27)Sediment supply is a primary factor in determining marsh response to sea level rise and is typically approximated through high‐resolution measurements of suspended sediment concentrations (SSCs) from adjacent tidal channels. ...