Development of a whole-of-Reef 3D hydrodynamic model
Project Leader: Dr Andreas Schiller, CSIRO
Hydrodynamic models simulate the advection and mixing of water, processes fundamental in controlling the fate and impact of freshwater, sediment, nutrients and pesticides delivered from catchments in to the receiving waters of the Great Barrier Reef lagoon. A robust and validated 3-dimensional hydrodynamic model is seen as a necessary precursor to the development of water quality and ecological response models that can be applied generically in catchments, estuaries and the lagoon. This MTSRF-funded project has developed a hydrodynamic model of the entire Great Barrier Reef that includes all of the important factors affecting currents, mixing, temperature and salinity within the lagoon and exchanges with the adjacent Coral Sea. A pilot 4-km resolution regional model has been established, including river inflows for a number of real-time gauged rivers, and is running in near-real-time. Inter-comparison between observed and predicted tidal sea levels, which drive the general circulation, are a powerful verification of a model’s performance, and the general agreement of both magnitude and phasing of tidal water level fluctuations at coastal stations throughout the Great Barrier Reef gives confidence in the accuracy of the model’s simulation of a dominant hydrodynamic process. Qualitative assessment of a pilot 2009 wet season hindcast of this model indicates general agreement in extent and timing of the predicted surface fresh water plume and the remotely sensed plume distribution. Predicted and observed sub-surface salinities also show good agreement. A pilot 1-km resolution model is currently undergoing preliminary evaluation for computational performance.