The role of bore collapse and local shear stresses on the spatial distribution of sediment load in the uprush of an intermediate-state beach

Jackson, Nancy L.; Masselink, Gerd; Nordstrom, Karl F.

doi:10.1016/s0025-3227(03)00328-1

Cited by 67 publications

(44 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In the last twenty years there has been a significant increase in the number of studies on the swash zone. Nowadays, there are different studies that deal with the terms that play a role in the dynamic at the swash zone: bore collapsing (Puleo et al 2000, Jackson et al 2004Aagard and Hughes 2006), backwash Mason 1994 or Butt andRussell 1999), advection (Jackson et al 2004 or Alsina et al 2009), infiltration/ex-filtration effects Nielsen 1997, Elfrink andBaldock 2002;Baldock and Nielsen 2010), asymmetries in velocity or acceleration (Roelvink and Stive 1989, Mariño-Tapia et al 2007, Houser and Barret, 2010Pedrozo-Acuña et al 2011), long wave and wave groups (Baldock et al 2011), etc.…”

Section: Introductionmentioning

confidence: 99%

Suspended sediment transport and beach dynamics induced by monochromatic conditions, long waves and wave groups

Caceres

Alsina

2016

Coastal Engineering

View full text Add to dashboard Cite

This study presents the analysis of the water surface elevation, velocity and suspended sediment concentration measurements obtained at a large wave flume under mobile bed conditions. The wave reproduced Erosive and Accretive conditions, and included Monochromatic, short waves perturbed with a free long wave, Bichromatic and Random conditions. Each tested condition started from a handmade 1/15 slope and lasted for an approximate time period of 2.4 hours (6 runs of the selected wave condition), to compare the different beach profile developments and, in particular, the events that control sediment transport in the swash and surf zones. All Erosive tested conditions produced a shoreline retreat and a bar at the breaking area whose development in time is directly correlated to the length of the breaking area. On the other hand, not all Accretive conditions present a shoreward transport, and random conditions do not seem to alter the initial profile. The processed data show the suspended sediment event control produced by the existence or absence of wave-backwash interactions in the swash zone. The existence of these interactions, and their number within the wave group, will be a key parameter in controlling the sediment stirring, water velocity magnitudes and, therefore, the suspended sediment fluxes in the inner surf and outer swash.

show abstract

Section: Introductionmentioning

confidence: 99%

Suspended sediment transport and beach dynamics induced by monochromatic conditions, long waves and wave groups

Caceres

Alsina

2016

Coastal Engineering

View full text Add to dashboard Cite

show abstract

“…From these studies, a general description of the swash cycle in relation to sediment transport is synthetized as follows. Injection of bore related turbulence contributes to the cross-shore advection of particles into the swash zone that, together with the local mobilization, are effective in transporting sediment during swash cycle initiation [Butt and Russell, 1999;Puleo et al, 2000;Petti and Longo, 2001;Jackson et al, 2004;Masselink et al, 2005;Aagaard and Hughes, 2006]. During the remainder of the decelerating uprush motion, the turbulence decays similar to grid turbulence [Cowen et al, 2003;Sou and Yeh, 2011;Lanckriet and Puleo, 2013] and more homogeneously [Zhang and Liu, 2008] as the flow reaches the maximum inundation limit toward land (e.g., run up distance).…”

Section: Introductionmentioning

confidence: 99%

On the role of infiltration and exfiltration in swash zone boundary layer dynamics

et al. 2015

View full text Add to dashboard Cite

Boundary layer dynamics are investigated using a 2‐D numerical model that solves the Volume‐Averaged Reynolds‐Averaged Navier‐Stokes equations, with a VOF‐tracking scheme and a k ‐ ϵ turbulence closure. The model is validated with highly resolved data of dam break driven swash flows over gravel impermeable and permeable beds. The spatial gradients of the velocity, bed shear stress, and turbulence intensity terms are investigated with reference to bottom boundary layer (BL) dynamics. Numerical results show that the mean vorticity responds to flow divergence/convergence at the surface that result from accelerating/decelerating portions of the flow, bed shear stress, and sinking/injection of turbulence due to infiltration/exfiltration. Hence, the zero up‐crossing of the vorticity is employed as a proxy of the BL thickness inside the shallow swash zone flows. During the uprush phase, the BL develops almost instantaneously with bore arrival and fluctuates below the surface due to flow instabilities and related horizontal straining. In contrast, during the backwash phase, the BL grows quasi‐linearly with less influence of surface‐induced forces. However, the infiltration produces a reduction of the maximum excursion and duration of the swash event. These effects have important implications for the BL development. The numerical results suggest that the BL growth rate deviates rapidly from a quasi‐linear trend if the infiltration is dominant during the initial backwash phase and the flat plate boundary layer theory may no longer be applicable under these conditions.

show abstract

“…These conditions form a realistic representation of hydrodynamic conditions under shoaling waves and in the outer surf zone, where breaking wave-generated turbulence has limited potential to mobilize near-bed sediment. In contrast, the near-bed layer in the inner surf and swash zones is directly affected by bore-generated turbulence [Puleo et al, 2000;Butt et al, 2004;Jackson et al, 2004;Aagaard and Hughes, 2006;. The impact of breaking wave-generated turbulence on the sheet flow layer has only recently been investigated Two-phase numerical models that resolve the granular dynamics and sediment-fluid interactions have led to an improved understanding of sheet flow [Hsu et al, 2004;Calantoni and Puleo, 2006;Amoudry et al, 2008;Bakhtyar et al, 2009Bakhtyar et al, , 2010Chen et al, 2011].…”

Section: Introductionmentioning

confidence: 99%

A semianalytical model for sheet flow layer thickness with application to the swash zone

Lanckriet

Puleo

2015

JGR Oceans

View full text Add to dashboard Cite

A new semianalytical model for the time-dependent thickness of the sheet flow layer that includes the effects of pressure gradients, bed slope, boundary layer growth, and bore turbulence is presented. The shear stress and boundary layer growth are computed using the boundary layer integral method. The model is expressed as two coupled ordinary differential equations that are solved numerically given a prescribed time series of free-stream velocity, horizontal pressure gradient and bore turbulence, which together represent the hydrodynamic forcing. The model was validated against two data sets of sheet flow layer thickness collected in oscillatory flow tunnels and one data set collected in the swash zone of a prototype-scale laboratory experiment. In the oscillatory flow tunnel data sets, sheet flow is mostly generated by shear stress, with pressure gradients providing an important secondary forcing around flow reversal. In the swash zone, pressure gradients and shear stresses alone are not sufficient to generate the large sheet flow layer thickness observed at the initial stages of uprush. Bore turbulence is most likely the dominant generation mechanism for this intense sheet flow.

show abstract

The role of bore collapse and local shear stresses on the spatial distribution of sediment load in the uprush of an intermediate-state beach

Cited by 67 publications

References 21 publications

Suspended sediment transport and beach dynamics induced by monochromatic conditions, long waves and wave groups

Suspended sediment transport and beach dynamics induced by monochromatic conditions, long waves and wave groups

On the role of infiltration and exfiltration in swash zone boundary layer dynamics

A semianalytical model for sheet flow layer thickness with application to the swash zone

Contact Info

Product

Resources

About