Authors: Beaman, R.J.
Publication: MTSRF Conference, 18-20 May 2010, Cairns, Australia.
A high-resolution digital elevation model (DEM) is a critical 3D dataset required to accurately simulate water mixing and current flow within a whole-of-Great Barrier Reef (GBR) scale hydrodynamic model (see MTSRF Project 2.5i.1). The finer-scale detail of the undersea landscape underpins the ability of the hydrodynamic model to resolve the effects of reefs and inter-reefal passages on water circulation, and hence the predictive ability of such models to simulate changes to the GBR environment under various climate change scenarios.
In addition, there is a critical lack of information about the location and spatial extent of deep-water ecosystems and seabed habitats for about a third of the GBR World Heritage Area (GBRWHA) lying deeper than 200 m. Most of the inter-reefal seabed shallower than 200 m on the GBR shelf, and many of the 2000+ coral reefs themselves, have never been adequately mapped with modern echosounder techniques. Therefore key seabed geomorphic features, such as shoal habitats and submerged reefs, remain largely hidden from view and outside of effective management.
The project aims to develop a new high-resolution depth model for the GBR and adjoining Coral Sea at a grid resolution of 3-arc second (about 100 m). The geographic coverage ranges from latitude 10° to 29° South; longitude 142° to 160° East. Including the adjacent Queensland coast, the new DEM will represent an area of about 3,000,000 km2.
In recent years there has been a vast increase in the quantity of bathymetric data obtained in the GBRWHA through a series of research vessel mapping expeditions. The project will utilise the latest data sourced from ship-based multibeam and singlebeam echosounder surveys, airborne lidar bathymetry surveys, and satellite remotely sensed data.
This paper describes the key objectives: (a) to identify and compile all potential data sources; and (b) the data preparation and grid development process.