SWASH ZONE BED LEVEL CHANGES AND SEDIMENT ENTRAINMENT AT THE SURF-SWASH BOUNDARY
Proceedings of the 32nd International Conference
PDF

Keywords

swash zone characteristics
bed level changes
bores at the surf-swash boundary

How to Cite

Jensen, S. G., Aagaard, T., & Baldock, T. E. (2011). SWASH ZONE BED LEVEL CHANGES AND SEDIMENT ENTRAINMENT AT THE SURF-SWASH BOUNDARY. Coastal Engineering Proceedings, 1(32), sediment.28. https://doi.org/10.9753/icce.v32.sediment.28

Abstract

In the process of estimating the effect of sediment advection into the swash zone from bore collapse, a method in which buried self-logging pressure transducers are used to measure bed level changes in the swash zone, over a timeframe of several hours to inter-swash level, has been tested against bed level changes obtained from rod measurements. The test shows perfect agreement in the upper and mid swash while minor disagreement (1 cm) in the lower swash occurred. The deployment of self-logging pressure transducers has proven to be an accurate, easy and flexible method to obtain highly detailed data on water levels and bed elevations in the swash zone. Water levels derived from the pressure transducers show that swash zone characteristics vary from the upper to lower swash. Using pressure transducers in the swash zone coupled with measurements of the hydrodynamics and sediment concentrations at the outer boundary of the swash zone will improve the ability to explain the role of sediment advection from bore collapse. In relation to this, a method which consistently identify bores at the surf-swash boundary and quantifies the suspended sediment load carried by such bores prior to their collapse and run-up in the swash zone, is also presented.
https://doi.org/10.9753/icce.v32.sediment.28
PDF

References

Aagaard, T., Hughes, M. G., 2006. Sediment suspension and turbulence in the swash zone of dissipative beaches. Mar. Geol. 228, 117-135. http://dx.doi.org/10.1016/j.margeo.2006.01.003

Baldock, T.E., Barnes, M.P., Hughes, M.G., 2005. Field observations of instantaneous cross-shore free surface profiles and flow depths in the swash zone. Proc. Coastal Dynamics 2005, Barcelona, ASCE.

Baldock, T. E., 2009. Discussion of "Measurements of wave-by-wave bed-levels in the swash zone" by Ian L. Turner, Paul E. Russell, Tony Butt, [Coastal Eng. 55 (2008) 1237-1242]. Coastal Engineering 56, 380-381.http://dx.doi.org/10.1016/j.coastaleng.2008.09.009

Blekinsopp, C. E., Turner, I. L., Masselink, G., Russell, P. E., 2009. Field measurements of net sediment flux from individual swashes on a sandy beach. Proc. Coastal Dynamics 2009, Tokyo. Paper No. 27.

Brocchini, M, Baldock, T., 2008. Recent advances in modelling swash zone dynamics: influence of surf-swash interaction on nearshore hydrodynamics and morphodynamics. Reviews of Geophysics 46, RG3003, 21pp.

Butt, T., Russell, P., 2000. Hydrodynamics and Cross-Shore Sediment Transport in the Swash-Zone of Natural Beaches: A Review. Journal of Coastal Research, 16(2), pp. 255-268.

Hughes, M., Masselink, G., Brander, R., 1997a. Flow velocity and sediment transport in the swash zone of a steep beach. Marine Geology 138, 91-103. http://dx.doi.org/10.1016/S0025-3227(97)00014-5

Hughes, M. G., Masselink, G., Hanslow, D., Mitchell, D., 1997b. Toward a better understanding of swash zone of swash zone sediment transport. Proc. Coastal Dynamics '97. ASCE, pp. 804-813.

Hughes, M. G., Aagaard, T., Baldock, T. E., 2007. Suspended sediment in the swash zone: heuristic analysis of spatial and temporal variations on concentration. Journal of Coastal Research, 23, pp. 1345-1354. http://dx.doi.org/10.2112/05-0531.1

Hughes, M., Moseley, A. S., 2007. Hydrokinematic regions within the swash zone. Continental Shelf Research 27, 2000-2013.http://dx.doi.org/10.1016/j.csr.2007.04.005

Jensen, S. G., Aagaard, T., Baldock, T. E., Kroon, A., Hughes, M., 2009. Berm formation and dynamics on a gently sloping beach; the effect of water level and swash overtopping. Earth Surf. Process. Landforms 34, 1533-1546. http://dx.doi.org/10.1002/esp.1845

KDI, 2001. The Sediment Budget along the West Coast of Jutland. Report, Danish Coastal Authority: Lemvig; 54pp. (In Danish).

Masselink, G., Hughes, M., 1998. Field investigation of sediment transport in the swash zone. Continental Shelf Research 18, 1179-1199. http://dx.doi.org/10.1016/S0278-4343(98)00027-2

Masselink, G., Russell, P., Turner, I., Blekinsopp, C., 2009. Net sediment transport and morphological change in the swash zone of a high-energy sandy beach from swash event to tidal cycle time scales. Marine Geology 267, 18-35.http://dx.doi.org/10.1016/j.margeo.2009.09.003

Power, H. E., Hughes, M. G., Aagaard, T., Baldock, T. E., 2010. Nearshore wave height variation in unsaturated surf. Journal of Geophysical Research, Vol 115, C08030, 15pp.

Pritchard, D., Hogg, A. J., 2005. On the transport of suspended sediment by a swash event on a plane beach. Coastal Engineering 52, 1-23. http://dx.doi.org/10.1016/j.coastaleng.2004.08.002

Puleo, J. A., Beach, R. A., Holman, R. A., Allen, J. S., 2000. Swash zone sediment suspension and transport and the importance of bore-generated turbulence. Journal of Geophysical Research, Vol. 105, No. C7, 17021-17044. http://dx.doi.org/10.1029/2000JC900024

Weir, F. M., Hughes, M. G., Baldock, T. E., 2006. Beach face and berm morphodynamics fronting a coastal lagoon. Geomorphology, 82, 331-346.http://dx.doi.org/10.1016/j.geomorph.2006.05.015

Wright L. D., Short A. D. 1984. Morphodynamic variability of surf zones and beaches; a synthesis. Marine Geology 56: 93-118. http://dx.doi.org/10.1016/0025-3227(84)90008-2

Authors retain copyright and grant the Proceedings right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this Proceedings.