Surf Zone Turbulence and Suspended Sediment Dynamics—A Review

Journal of Marine Science and Engineering

Troels Aagaard¹  Drude F. Christensen¹  Gerben Ruessink²  Michael G. Hughes³  Joost Brinkkemper⁴ 

[1] Department of Geosciences and Natural Resource Management, University of Copenhagen, DK-1353 Copenhagen, Denmark;Department of Physical Geography, Faculty of Geosciences, Utrecht University, 3584 CS Utrecht, The Netherlands;Environment, Energy and Science, NSW Department of Planning Industry and Environment, Wollongong, NSW 2124, Australia;WaterProof Marine Consultancy & Services BV, 8221 RC Lelystad, The Netherlands;

关键词: turbulence;    suspended sediment;    sediment transport;    breaking waves;    beach recovery;   

DOI  :  10.3390/jmse9111300

来源: DOAJ

【 摘 要 】

The existence of sandy beaches relies on the onshore transport of sand by waves during post-storm conditions. Most operational sediment transport models employ wave-averaged terms, and/or the instantaneous cross-shore velocity signal, but the models often fail in predictions of the onshore-directed transport rates. An important reason is that they rarely consider the phase relationships between wave orbital velocity and the suspended sediment concentration. This relationship depends on the intra-wave structure of the bed shear stress and hence on the timing and magnitude of turbulence production in the water column. This paper provides an up-to-date review of recent experimental advances on intra-wave turbulence characteristics, sediment mobilization, and suspended sediment transport in laboratory and natural surf zones. Experimental results generally show that peaks in the suspended sediment concentration are shifted forward on the wave phase with increasing turbulence levels and instantaneous near-bed sediment concentration scales with instantaneous turbulent kinetic energy. The magnitude and intra-wave phase of turbulence production and sediment concentration are shown to depend on wave (breaker) type, seabed configuration, and relative wave height, which opens up the possibility of more robust predictions of transport rates for different wave and beach conditions.

【 授权许可】

Unknown