Modelled flood plumes - central and northern Great Barrier Reef

Full description

MECCA - a verified 3-dimensional hydrodynamic model was used to simulate river plume dynamics.Model simulations were compiled to examine the intensity, duration and frequency of different lower salinity events. Return periods were then calculated from the annual frequency of such events.The model was forced using daily river discharge data and time-series wind observation data. A mixing parameter was used to simulate tidal forcings.
Use of computer simulation to understand the fate of riverine water as it mixes and moves around with the currents and winds.Used to quantify the connectivity between coastal runoff and the central and northern GBR.The simulations demonstrate a range of common spatial patterns and unusual events that can be expected from a dynamic process. Using this information a risk assessment using return period analysis of the frequency of different impact events can be undertaken to identify 'high-risk' regions or reefs.Environmental managers can use analyses based on the model for risk assessment on implications for dilutions and residence times of dissolved and suspended material carried within catchment runoff, as well as identifying potential plume pathways and travel times for the runoff and its contents to reach reefs.
The model has been used for flood plume analyses on the Burdekin River (1966 - 1995); the Burdekin, Herbert, Tully, Johnstone, Russell, Barron, Daintree, Endeavour, Jeannie and Normanby Rivers (1969 - 1998); and the GBR lagoon.The database for analysis by the model created includes information on the duration of exposure to fresh water (exceedance), the minimum salinity and the return periods for the modelled domain.Wind data (recorded every 3 hours) was obtained from the Mackay weather station (just south of model domain) for the period 1966-1991, and from the AIMS weather stations for the period 1992-1998. Daily discharge data from the rivers was obtained from the Queensland Water Resources Commission. Tidal influences were included implicitly via the mixing parameters based on the work of King and Wolanski (1996). Thus these data can be applied to the model to simulate any of the major flood events of the rivers in this region over the last 30 years. The model has subsequently been run for the 2008 flood period.

Lineage

Maintenance and Update Frequency: notPlanned

Statement: Statement: Data converted from binary direct access format to NetCDF.

Notes

Credit
King, Brian A, Dr (Principal Investigator)

Credit
McAllister, FA (Custodian)