Physical Mechanisms of Wave-Induced Sediment Resuspension

Author(s):  
Yonggang Jia ◽  
Xiaolei Liu ◽  
Shaotong Zhang ◽  
Hongxian Shan ◽  
Jiewen Zheng
2019 ◽  
Vol 51 (1) ◽  
pp. 129-154 ◽  
Author(s):  
Leon Boegman ◽  
Marek Stastna

Large-amplitude internal waves induce currents and turbulence in the bottom boundary layer (BBL) and are thus a key driver of sediment movement on the continental margins. Observations of internal wave–induced sediment resuspension and transport cover significant portions of the world's oceans. Research on BBL instabilities, induced by internal waves, has identified several mechanisms by which the BBL is energized and sediment may be resuspended. Due to the complexity of the induced currents, process-oriented research using theory, direct numerical simulations, and laboratory experiments has played a vital role. However, experiments and simulations have inherent limitations as analogs for oceanic conditions due to disparities in Reynolds number and grid resolution, respectively. Parameterizations are needed for modeling resuspension from observed data and in larger-scale models, with the efficacy of parameterizations based on the quadratic stress largely determining the accuracy of present field-scale efforts.


2019 ◽  
Vol 55 (2) ◽  
pp. 1279-1295 ◽  
Author(s):  
D. C. Roberts ◽  
P. Moreno‐Casas ◽  
F. A. Bombardelli ◽  
S. J. Hook ◽  
B. R. Hargreaves ◽  
...  

Estuaries ◽  
1999 ◽  
Vol 22 (1) ◽  
pp. 39 ◽  
Author(s):  
Lars Chresten Lund-Hansen ◽  
Mona Petersson ◽  
Wayan Nurjaya

2020 ◽  
Author(s):  
Gábor Fleit ◽  
Sándor Baranya

<p>The ever-increasing demand for fluvial navigation and the more and more efforts made for ecologically sustainable water usage (facilitated by e.g. the Water Framework Directive of the EU) have highlighted potential conflicts of interests in river management. Riverine traffic has notable hydrodynamic effects, i.e. the local hydraulic regime of river reaches may get significantly altered by wave events generated by passing vessels. As ship waves reach the shallower areas, the related hydrodynamic stresses affect the near-bed boundary layer increasingly, bed shear stress increases gradually, leading to the resuspension of fine sediments. In order to find out more about the nature of this phenomenon, simultaneous ABS (acoustic backscatter sensor) and ADV (acoustic Doppler velocimeter) measurement were performed in the Hungarian Danube. Such measurement not only offer the opportunity to reveal the likely interconnections between hydrodynamic variables (e.g. flow velocity, turbulent kinetic energy) and suspended sediment concentrations (SSC), but the found correlation between ABS data and the backscatter strength of the ADV also suggests the applicability of the latter for the estimation of instantaneous SSC in a high temporal resolution.</p>


2019 ◽  
Vol 870 ◽  
pp. 848-869 ◽  
Author(s):  
E. Horne ◽  
F. Beckebanze ◽  
D. Micard ◽  
P. Odier ◽  
L. R. M. Maas ◽  
...  

Quantifying the physical mechanisms responsible for the transport of sediments, nutrients and pollutants in the abyssal sea is a long-standing problem, with internal waves regularly invoked as the relevant mechanism for particle advection near the sea bottom. This study focuses on internal-wave-induced particle transport in the vicinity of (almost) vertical walls. We report a series of laboratory experiments revealing that particles sinking slowly through a monochromatic internal wave beam experience significant horizontal advection. Extending the theoretical analysis by Beckebanze et al. (J. Fluid Mech., vol. 841, 2018, pp. 614–635), we attribute the observed particle advection to a peculiar and previously unrecognized streaming mechanism in the stratified boundary layer originating at the lateral walls. This vertical boundary layer streaming mechanism is most efficient for significantly inclined wave beams, when vertical and horizontal velocity components are of comparable magnitude. We find good agreement between our theoretical prediction and experimental results.


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