Modelling of Moreton Bay Using an Ocean/Coastal Circulation Model

A fully re-locatable ocean/coastal modeling system (HYDROMAP) has recently been enhanced with bathymetric and tidal databases and multi-level gridding tools to ensure rapid and reliable model setup and execution. HYDROMAP was recently employed to generate reliable currents for Moreton Bay, Australia, as input into the National Oil Spill Trajectory Model (OSTM) system. The hydrodynamic model domain was set-up to encompass the entire Moreton Bay (including Bribie Island), the South Pacific Ocean and as far south as the Gold Coast Seaway. Employing HYDROMAP's innovative gridding approach, the resolution of the initial rectangular grid was increased by up to four levels (i.e. from 2 km to 62 m) to resolve the extensive shallow tidal flats, numerous islands and small channels. The advantage of the HYDORMAP gridding approach, is the ability to simulate large areas of widely differing spatial scales within the one grid domain. The model predictions were compared to three National Tidal Facility stations located within Moreton Bay and were found to compare very well to all stations, clearly demonstrating the reliability and accuracy of the model. With this type of rapid decision support, managers will have the tools to provide estimates of currents to assess a variety of environmental impacts (i.e. oil spills, chemical spills, search and rescue, dredge spoil discharges) regardless of the complexity of the area.