Modelling of three dimensional tidal dynamics in Darwin Harbour, Australia

A three dimensional finite element numerical model, the Resource Management Associates model, is used to simulate the three dimensional hydrodynamics in Darwin Harbour. Observed elevation data are used to calibrate and validate it. The modelling study shows that the hydrodynamics in the region is predominantly tidally driven, with the main constituent being the M2 tide. The amplitude of this tide is damped in the inner harbour because of the tidal choking of the narrow channel connecting it with the outer harbour. When the tide propagates into the entrances of the three arms (East, West and Middle) extending from the channel, its amplitude increases due to the shallower geometry and then decreases in the arms due to the energy dissipation caused by the bottom friction. The tidal current reaches its maximum speed along the channel to the Middle Arm in which the current ellipse becomes rectilinear. References D. S. Byun, X. H. Wang, and P. E. Holloway. Tidal characteristic adjustment due to dyke and seawall construction in the Mokpo Coastal Zone, Korea. Estuarine, Coastal and Shelf Science , 59(2):185--196, 2004. doi:10.1016/j.ecss. 2003.08. 007 J. Fortune and J. Drewry. Darwin Harbour region report cards 2009. Aquatic Health Unit, Department of Natural Resources, Environment, The Arts and Sport. Palmerston NT 0831 , page 62, 2009. http:www.nt. gov.au/nreta/water/aquatic/index.html A. M. Hoguane, A. E. Hill, J. H. Simpson, and D. G. Bowers. Diurnal and tidal variation of temperature and salinity in the Ponta Rasa mangrove swamp, Mozambique. Estuarine, Coastal and Shelf Science , 49(2):251--264, 1999. doi:10.1006/ecss.1999. 0499 P. E. Holloway and M. A. Merrifield. Internal tide generation by seamounts, ridges, and islands. J. Geophys. Res. , 104(C11):25937--25951, 1999. doi:10.1029/1999jc900207 l. P. King. Chapter 2: Advection diffusion equations for transport , pages 1--7. Resource Modelling Associates, Sydney, Australia, 2009. B. Knoppers, K. Bjorn, and J.P. Carmouze. Trophic state and water turn-over time in six choked coastal lagoons in Brazil. Biogeochemistry , 14(2):149--166, 1991. doi:10.1007/bf00002903 A. J. Mehta. Laboratory studies on cohesive sediment deposition and erosion , pages 427--445. Springer Verlag, Berlim, 1988. M. G. Michie. Distribution of foraminifera in a macrotidal tropical esturay: Port Darwin, Northern Territory of Australia. Australian Journal of Marine and Freshwater Research , 38:249--259, 1987. http://www.publish. csiro.au/? act=view_file&file_id=MF9870249.pdf Robert J. Nicholls. Analysis of global impacts of sea-level rise: a case study of flooding. Physics and Chemistry of the Earth, Parts A/B/C , 27(32--34):1455--1466, 2002. doi:10.1016/S1474-7065(02)00090-6 D. T. Pugh. Tides, Surges and Mean Sea-Level . John Wiley and Sons, New York, 1987. http://eprints.soton. ac.uk/19157/1/sea-level.pdf D. J. Reed. Sea-level rise and coastal marsh sustainability: geological and ecological factors in the Mississippi delta plain. Geomorphology , 48(1--3):233--243, 2002. doi:10.1016/S0169-555X(02)00183-6 J. H. Simpson and J. R. Hunter. Fronts in the Irish Sea. Nature , 250(5465):404--406, 1974. doi:10.1038/250404a0 J. Smagorinsky. General circulation experiments with the primitive equations: I. the basic experiment. Mon. Wea. Rev. , (91):99--164, 1963. C. Viseras, J. Fernandez, F. Garcia-Garcia, J. Soria, M. Calvache, and P. Juregui. Dynamics of sedimentary environments in the accelerated siltation of a reservoir: the case of Alhama de Granada, southern Spain. Environ Geol , 56:1353--1369, 2009. doi:10.1007/s00254-008-1231-2 Kathelijne M. Wijnberg. Environmental controls on decadal morphologic behaviour of the Holland coast. Marine Geology , 189(3--4):227--247, 2002. doi:10.1016/S0025-3227(02)00480-2 D. Williams. Part 1:hydrodynamics and sediment transport. Technical report, Australian Institute of Marine Science, Arafura Timor Research Facility, 2009. D. Williams, W. Ewolanski, and S. Spagnol. Hydrodynamics of Darwin Harbour , chapter 26, pages 461--476. Springer, in The Netherlands, 2006. C. D. Woodroffe, K. N. Bardsley, P. J. Ward, and J. R. Hanley. Production of mangrove litter in a macrotidal embayment, Darwin Harbour, N.T. , Australia. Estuarine, Coastal and Shelf Science , 26(6):581--598, 1988. doi:10.1016/0272-7714(88)90035-2 L. D. Wright, J. D. Boon, J. P. Xu, and S. C. Kim. The bottom boundary layer of the bay stem plains environment of lower chesapeake bay. Estuarine, Coastal and Shelf Science , 35(1):17--36, 1992. doi:10.1016/S0272-7714(05)80054-X