A key component of marine bioregional planning is to map the spatial patterns of marine biodiversity, often measured as species richness, total abundance or abundance/presence of key taxa. In this study, predictive modelling approaches were used to map soft bottom benthic biodiversity on the Carnarvon Shelf, Western Australia, using a range of physical surrogates. This surrogacy approach could also explicitly link physical environmental attributes to the marine biodiversity patterns. The statistical results show that between 20% and 37% of variances on the two biodiversity measures (Species Richness and Total Abundance) were explained by the Random Forest Decision Tree models. The best statistical validation performance was found at the Point Cloates area. This was followed by the Gnaraloo area, then by the Mandu Creek area. The models identified different individual physical surrogates for the three study areas and the two biodiversity measures. However, it was found that the infaunal biodiversity at the three study areas of the Carnarvon Shelf were driven by similar ecological process. Sediment properties were the most important physical surrogates for the infaunal biodiversity. Coarser and heterogeneous sediments favour higher infaunal species richness and total abundance. The prediction maps indicate the highest infaunal biodiversity at deeper water of the Point Cloates area. In contrast, the majority of the Mandu creek area has low infaunal biodiversity. This may be due to the much narrower shelf width (e.g., ~6 km) in this part of Carnarvon Shelf than the Point Cloates and Gnaraloo areas. The narrow shelf would limit the space for oceanographic processes to work on the sediment and develop heterogeneous sediment properties that support diverse and productive infaunal species.

The MODIS (or Moderate Resolution Imaging Spectroradiometer) 250 m EVI dataset provides a valuable ongoing means of characterising and monitoring changes in land use and resource condition. However the multiple factors that influence a time series of greenness data make the data difficult to analyse and interpret. Without prior knowledge, underlying models for time series in a given remote sensing image are often heterogeneous. So while conventional time series analysis methods such as wavelet transform and Fourier analysis may work well for part of the image, these models are either invalid or must be substantially re-parameterised for other parts of the image. To overcome these challenges we propose a new approach to distil information from earth observation time series. The characteristics of a remote sensing time series are represented by a set of statistics (which we call coefficients) selected to correspond to the dynamics of a natural system. To ensure the coefficients are robust and generic, statistics are calculated independently by applying statistical models with less complexity on shorter segments within the time series. An International Standards Organization (ISO) Land Cover classification was generated for cropping regions in the Gwydir and Namoi catchments, in Australia. Areas identified in the classification as irrigated and rain fed cropping were analysed using a tailored time series analysis tool. The crop analysis tool identifies time series features such as the number and duration of fallow periods, crop timing, presence/absence of a crop during a year for a specific growing season. This information is combined with paddock boundaries derived from Landsat imagery to provide detailed year-by-year insight into cropping practices in the Gwydir and Namoi catchments.

To follow

Collation of extended abstracts presented at the pmd*CRC conference 11-12 June 2008

The Fitzoy Estuary is one of several macrotidal estuaries in tropical northern Australia that face ecological change due to agricultural activities in their catchments. The biochemical functioning of such macrotidal estuaries is not well understood in Australia, and there is a pressing need to identify sediment, nutrient and agrochemical pathways, sinks and accumulation rates in these extremely dynamic environments. This is particularly the case in coastal northern Queensland because the impact of water quality changes in rivers resulting from vegetation clearing, changes in land-use and modern agricultural practices are the single greatest threat to the Great Barrier Reef Marine Park. This report includes: 1 Aims and Research questions 2 Study Area 3 Climate and Hydrology 4 Geology 5 Vegetation and land use 6 Methods 7 Sampling strategy 8 Water column observations and samples 9 Bottom sediment properties 10 Core and bottle incubations 11 Data analysis 12 Results 13 Discussion 14 The roll of Keppel Bay in accumulating and redirecting sediment and nutrients from the catchment 15 Sediment biogeochemistry 16 Links between primary production, biogeochemistry and sediment dynamics: A preliminary zonation for Keppel Bay 17 Conclusions

Increasing the knowledge of ocean current patterns in Torres Strait region is of direct interest to indigenous communities and industries such as fisheries and shipping that operate in the region. Ocean circulation in Torres Strait influences nearly all aspects of the ecosystem, including sediment transport and turbidity patterns, primary production in the water column and bottom sediments, and recruitment patterns for organisms with pelagic phases in their life cycles. This study is the first attempt to describe the water circulation and transport patterns across Torres Strait and adjacent gulfs and seas, on time scales from hours to years. It has also provided a framework for an embedded model describing sediment transport processes (described in Margvelashvili and Saint-Cast, 2006). The circulation model incorporated realistic atmospheric and oceanographic forcing, including winds, waves, tides, and large-scale regional circulation taken from global model outputs. Simulations covered a hindcast period of eight years, allowing the tidal, seasonal, and interannual flow characteristics to be investigated. Results demonstrated that instantaneous current patterns were strongly dominated by the barotropic tide and its spring-neap cycle. However, longer-term transport through Torres Strait was mainly controlled by seasonal winds, which switch from north-westerly monsoon winds in summer to south-easterly trades in winter. Model results were shown to be relatively insensitive to internal model parameters. However, model performance was strongly dependent on the quality of the forcing fields. For example, the prediction of low-frequency inner-shelf currents was improved substantially when temperature and salinity forcing based on the average seasonal climatologies was replaced by that from global model outputs. Uncertainties in the tidal component of the forcing also limited model skill, particularly predictions to the west of Cape York which were strongly dependent on the sealevels imposed along the open boundary in Gulf of Carpentaria.

The Paterson National Geoscience Agreement project is using a number of tools to better understand the time-space evolution of the northwest Paterson Orogen in Western Australia. One of these tools, 3D Geomodeller, is an emerging technology that constructs three-dimensional (3D) volumetric models based on a range of geological information. The Paterson project is using 3D Geomodeller to build geologically-constrained 3D models for the northwest Paterson Orogen. This report documents the model building capability and benefits of 3D Geomodeller and highlights some of the geological insights gained from the model building exercise. The principal benefit of 3D Geomodeller is that it provides geoscientists with a rapid tool for testing multiple working hypotheses. The Cottesloe Syncline district was selected as the focus for a trial of the 3D Geomodeller software. The 3D model was built by members of the Paterson Project, as well as model building specialists within Geoscience Australia. The resultant Cottesloe Syncline model including two dimensional sections, maps and images was exported from 3D GeoModeller and transformed into a Virtual Reality Modelling Language (VRML), enabling a wide audience to view the model using readily available software.

The Collaborative Research Centre for Greenhouse Gas Technologies (CO2CRC) Program 3.2 Risk Assessment is working toward a risk assessment procedure that integrates risk across the complete CCS system and can be used to meet the needs of a range of stakeholders. Any particular CCS project will hold the interest of multiple stakeholders who will have varied interests in the type of information and in the level of detail they require. It is unlikely that any single risk assessment tool will be able to provide the full range of outputs required to meet the needs of regulators, the general public and project managers; however, in many cases the data and structure behind the outputs will be the same. In using a suite of tools, a well designed procedure will optimize the interaction between the scientists, engineers and other experts contributing to the assessment and will allow for the required information to be presented in a manner appropriate for each stakeholder. Discussions of risk in CCS, even amongst the risk assessment community, often become confused because of the differing emphases on what the risks of interest are. A key question that must be addressed is: 'What questions is the risk analysis trying to answer?' Ultimately, this comes down to the stakeholders, whose interests can be broken into four target questions: - Which part of the capture-transport-storage CCS system? - Which timeline? (project planning, project lifespan, post closure, 1,000 years, etc) - Which risk aspect? (technical, regulatory, economic, public acceptance, or heath safety and environment) - Which risk metric? (Dollars, CO2 lost, dollars/tonne CO2 avoided, etc.) Once the responses to these questions are understood a procedure and suite of tools can be selected that adequately addresses the questions. The key components of the CO2CRC procedure we describe here are: etc

No abstract available

The Capel and Faust basins lie at water depths of 1,500-3,000 m 800 km east of Brisbane. Geoscience Australia began a petroleum prospectivity study of these remote frontier basins with the acquisition of 2D geophysical data (seismic reflection, refraction, gravity, magnetic, multi-beam bathymetry) across an area of 87,000 km2 during 2006/07. The approach mapped the complex distribution of sub-basins and determined sediment thickness through integration of traditional 2D time-domain seismic interpretation techniques with 3D mapping, visualisation and gravity modelling. Forward and inverse 3D gravity models were used to inform the seismic interpretation process and test the seismic basement pick. Gravity models had three sediment layers with inferred average densities of 1.85, 2.13, 2.31 t/m3 overlying a pre-rift basement of density 2.54 t/m3, itself considered to consist of older basin material evidently intruded by igneous rocks. Conversion of travel times of interpreted seismic horizons to depth domain was achieved using a quadratic function derived from ray-tracing forward modelling of refraction data supplemented by stacking interval velocities, and densities for gravity modelling were inferred from the same velocity models. These models suggest sediment of average velocity 3.5 km/s reaches a thickness exceeding 6 km in the northwest of the area, and for the first time mapped the extent and depth of sediment in these basins. The results of the study have confirmed that sediment thickness in the Capel and Faust basins is sufficient in places for potential petroleum generation.