Modelling of three dimensional tidal dynamics in Darwin Harbour, Australia

Abstract

A three dimensional finite element numerical model, the Resource Management Associates model, is used to simulate the three dimen- sional 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. © Austral. Mathematical Soc. 2011.