MORPHOLOGY OF COASTAL LAGOON ENTRANCES: WAVES VERSUS TIDES

Thuy T. Vu, Peter Nielsen, David P. Callaghan

Abstract


Tidal inlets are important parts of coastal ecosystems and have been the topic of active coastal engineering research for close to a century. The earliest researchers probably realised that the equilibrium cross-section shape, around which a given inlet oscillates due to changing tides and waves and due to occasional storm surges and/or freshwater floods, can be described in terms of the potential bay or lagoon area and the typical wave and tide parameters for the location. However, till now, the effects of waves and tides have not been combined into an effective parameter for inlet classification or formulae for inlet cross-section area, delta volumes, or morphological time scales. This paper gives such a parameter, which necessarily accounts for tidal period as well as tidal prism and wave height. The effectiveness of this new parameter for quantitative classification of inlets is subsequently demonstrated.

Keywords


Tidal inlets, funnel shaped estuaries, inlet closure, morphological time-scales, ICOLLS

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References


Bruun, P. (1966): Tidal Inlets and Littoral Drift. P. Bruun, Washington DC, 193 pp.

Bruun, P. (1978): Stability of tidal inlets. Elsevier 506 pp.

Byrne, R J, R A Gammisch & G R Thomas (1980): Tidal prism inlet relations for small tidal inlets. Proc 17th Int Conf Coastal Eng, Sydney, ASCE, pp 2517-2533.

Dean, R. G. & R. A. Dalrymple (2002): Coastal processes with engineering applications. Cambridge Univ Press, 475pp.

Hayes, M.O., 1979. Barrier Island Morphology as a Function of Tidal and Wave Regime. In: S.P. Leatherman (Editor), Barrier Islands from the Gulf of St. Lawrence to the Gulf of Mexico. Academic Press, New York: 1-27.

Hayes, M. O. (1991): Geomorphology and sedimentation patterns of tidal inlets: A review. Proc Coastal Sediments ’91, ASCE, pp 1343-1355.

Heap, A., S. Bryce, D. Ryan, L. Radke, C. Smith, P. Harris & D. Heggie (2001): Australian estuaries and coastal waterways: a geoscience perspective for improved and integrated resource management. Aust Geol Surv Org Rep to the National land and water resources audit. Theme 7: ecosystem health. 188pp.

Jarret J T (1976): Tidal prism inlet area relationships. GITI Report 3, U S Army Coastal Engineering Research Center, Fort Belvoir Va.

Kulmar, M, B Modra & M Fitzhenry (2013): The New South Wales Wave Climate Improved Understanding through the Introduction of Directional Wave Monitoring Buoys. Proc Coasts and Ports ’13.

Kraus, N C, 1998. Inlet cross-section area calculated by process based model, Proc 26th Int Conf Coastal Eng, ASCE, pp 3265-3278.

Kraus, N. C. (2010): Engineering of tidal inlets and morphologic consequences. In: Y.C. Kim (Editor), Handbook of coastal and ocean engineering. World Scientific, Los Angeles, USA, pp. 867-900.

Manly Hydraulics Laboratory (2010): NSW estuary and river water levels annual summary. Report MHL2009.

Masselink, G. & M. G. Hughes (2003): Introduction to coastal processes and Geomorphology. Arnold, 354pp.

Nielsen, P. (2009): Coastal and estuarine processes. World Scientific, pp 343.

O’Brien, M. P. (1931): Estuary tidal prisms related to entrance areas. Civil Engineering, Vol 1, No , pp 738-739.

O’Brien, M. P. (1969): Equilibrium flow areas of inlets on sandy coasts. J Waterways and Harbors Div ASCE, pp 43-52.

Ranasinghe, R. & C. Pattiaratchi (2003): The seasonal closure of tidal inlets: Causes and effects. Coastal Eng J, Vol 45, pp 601-627.

Roper, A., B. Creese, P. Scanes, K. Stephens, R. Williams, J. Dela-Cruz, G. Coade, B. Coates & M. Fraser (2011): Assessing the condition of estuaries and coastal lake ecosystems in NSW. Estuaries and coastal lakes Technical report series. NSW Government. ISBN 978 1 74293 338 2, 269pp.

Roy, P. S., R. J. Williams, A. R. Jones, I. Yassini, P. J. Gibbs, B. Coates, R. J. West, P. R. Scanes, J. P. Hudson,& S. Nichol (2001): Structure and function of south-east Australian estuaries. Estuarine, Coastal and Shelf Science Vol 35, pp 351-384.

Takeda, I. & T. Sunamura (1982): Formation and height of berms. Trans Jap Geomorph Union. Vol 3, pp 145-157.

Thuy, T. T. V. (2013): Aspects of inlet geometry and dynamics. PhD thesis, The University of Queensland. http://espace.library.uq.edu.au/view/UQ:322272

Thuy, T. T. V., P. Nielsen & D. P. Callaghan (2013): Inferring inlet morphodynamics and hydraulic parameters from tidal records: A case study of four closure events of Avoca Lake Australia. Int J Earth Sciences & Eng, Vol 6 No 2, pp 225-231.




DOI: https://doi.org/10.9753/icce.v34.sediment.89