Severe wind has major impacts on exposed human settlements and infrastructure, while climate change is expected to increase the severe wind hazard in many regions of Australia. The Risk and Impact Analysis Group (RIAG) in Geoscience Australia (GA) has developed a series of techniques to analyse the impact of severe wind imposed on the residential buildings under current and future climate. The process includes four components: hazard, exposure, vulnerability and risk. Severe wind hazard represents site specific wind speed values for different return periods (e.g. 500-year, 2000-year return periods), which may be derived by the wind loading standard (AS/NZS 1170.2), or be a result of modelling for current or future climates. GA has developed a National Exposure Information System (NEXIS), a repository of spatial and structural information of infrastructure exposed and vulnerable to natural hazards. NEXIS has also been extended to consider the number of future residential structures by utilising simple spatial relationships. Using an expert evaluation process, GA has developed a series of fragility curves which relate wind speed to the expected level of damage to residential buildings (measured as a percentage of the total replacement cost) in specific regions in Australia. These curves include consideration of factors such as building location, age, roof material, wall material, and so on. Given a certain intensity of severe wind imposed on a certain type of residential building in a specific region, the physical impact to a community can be determined in terms of the economic loss and casualties. By applying above concepts and procedures, based on sample data from the selected cities, we have integrated these three components (hazard, residential buildings exposure and vulnerability) within a computational framework to derive severe wind risk under both current climate and for a range of climate scenarios. These processes will be utilised for the assessment of climate change adaptation strategies concerning structural wind loading.

A depth to magnetic basement map has been produced for the Gawler-Curnamona region of South Australia. The map combines depth to magnetic source estimates with outcrop, drill hole and seismic data. The spectral domain method of analysing the slope of straight line segments in the power spectrum was used to produce the majority of the magnetic source depth estimates. The spectral domain method was incorporated into a semi-automated in-house software package to rapidly produce the regional scale map. The reliability of the depth to magnetic basement map is heavily dependent on the reliability of the depth to magnetic source estimation methods. There are a number of factors that can lead to errors, such as data quality and wrongly assigning magnetic sources to the cover or basement. The spectral domain method tends to slightly over estimate depths, however the average absolute errors are less than %30 when compared to known depths which is considered reasonable for the production of this type of regional scale map. The map delineates large areas of prospective Gawler Craton and Curnamona Province basement beneath less than 300 m of cover material, providing a useful tool for the mineral explorer. The map also delineates large areas under thick sequences of sediments, greater than 1000 m, which may prove of interest for the hydrocarbon explorer or act as a thermal blanket for the geothermal explorer.

Many countries in the Pacific rely heavily on their groundwater resources for drinking water, and for quite a few islands it is the only reliable source of water throughout the year. Changes in rainfall patterns and sea-level rise due to climate change are likely to threaten the availability and quality of groundwater in the future. Despite this threat, there is limited knowledge of the vulnerability of Pacific-Island aquifers to climate change at a regional scale. Currently, the sustainability of groundwater in the South Pacific is understood primarily through specific local-scale assessments of varying detail, with many locations unsurveyed. As the South Pacific is comprised of 1000s of small islands, it is not feasible to individually assess the groundwater resources of each island. Based on their geological makeup, South-Pacific Islands can be broadly classified as carbonate, continental, volcanic or composite (mixture of volcanic and carbonate) types. Previous hydrogeological investigations are generally biased towards carbonate-island types such as coral atolls and raised limestone islands and their associated fresh groundwater resources. However, in many of the South-Pacific Island countries volcanic-rock aquifers are also an important source of freshwater. This study aims to develop a systematic regional-scale typology for the Pacific Islands that considers all island situations, based primarily on hydrogeological characteristics. This will contribute to a hydrogeological framework in order to describe and understand how groundwater vulnerability to climate change differs between different hydrogeological settings and in different parts of the region. This will assist policy makers in the allocation of climate-change funding and monitoring, management and adaptation assistance.

Hydrogeology of East Timor

The Australian National Gravity Database (ANGD) contains over 1.8 million gravity observations from over 2,000 surveys conducted in Australia over the last 80 years. Three processes are required to correct these observations for the effects of the surrounding topography: firstly a Bouguer correction (Bullard A), which approximates the topography as an infinite horizontal slab; secondly a correction to that horizontal slab for the curvature of the Earth (Bullard B); and thirdly a terrain correction (Bullard C), which accounts for the undulations in the surrounding topography. These three corrections together produce complete bouguer anomalies. Since February 2008, a spherical cap bouguer anomaly calculation has been applied to data extracted from the ANGD. This calculation applies the Bullard A and Bullard B corrections. Terrain corrections, Bullard C, have now been calculated for all terrestrial gravity observations in the ANGD allowing the calculation of complete bouguer anomalies. These terrain corrections were calculated using the Shuttle Radar Topography Mission 3 arc-second digital elevation data. The complete bouguer anomalies calculated for the ANGD provide users of the data with a more accurate representation of crustal density variations through the application of a more accurate Earth model to the gravity observations.

An integrated analysis of geoscience information and benthos data have been used to identify seafloor habitats and associated benthic communities in the near-shore environment of the Vestfold Hills, East Antarctica. A multibeam echo-sounder was used to collect high-resolution bathymetry of the seafloor to depths of 215 m. A towed underwater video was used to identify macrobenthos along 16 transects. Abiotic variables including depth, backscatter intensity, substrate, slope, seafloor features (e.g. iceberg scours, sand ripples) and latitude were extracted from the multibeam and video datasets. Multivariate analysis of the benthos data was used to identify discrete benthic communities within the study area. Analysis of bio-physical relationships indicates that these benthic communities occur within distinct geographical regions and seafloor habitats. The habitats are distinguished primarily on the basis of depth and substrate. The two dominant seafloor habitats and associated benthic communities are: 1) deep, muddy basins with low to medium biological cover, consisting predominantly of bivalves, urchins, and seapens; and 2) shallow rocky outcrops, typically covered in dense macroalgae communities and associated invertebrates such as amphipods, spirorbid polychaetes and holothurians. In between are transition zones which provide habitat to mixed benthic communities. This study demonstrates the efficacy of using multibeam systems to survey large areas of the seafloor and collect high-resolution baseline data across previously unexplored regions. This baseline data is critical to improve our understanding of ecosystem dynamics and the relationships between biota and habitats and allows managers to make informed decisions about the effects of different activities on marine habitats.

Global climate change is putting Australia's infrastructure and in particular coastal infrastructure at risk. More than 80% of Australians live within the coastal zone. Almost 800,000 residences are within 3km of the coast and less than 6m above sea level. Much of Australia's land transport is built around road and rail infrastructure which is within the threatened coastal zone. A significant number of Australia's ports, harbours and airports are under threat. Australia's coastal zone contains several major cities, and supports agriculture, fisheries, tourism, coastal wetlands and estuaries, mangroves and other coastal vegetation, coral reefs, heritage areas and threatened species or habitats. Sea level rise is one physical effect of rising sea temperatures and is estimated at about 0.146m for 2030 (IPCC 2007) and up to 1.1m for 2100 (Antarctic and Climate Ecosystems CRC). The warming is likely to result in increases in intensity of both extra-tropical and tropical storms (spatially dependent) which are predicted to increase storm surge and severe wind hazard. Beaches, estuaries, coastal wetlands, and reefs which have adapted naturally to past changes in climate (storminess) and sea level over long time scales, now are likely to face faster rates of change. In many cases landward migration may be blocked by human land uses and infrastructure. Adaptation options include integrated coastal zone assessments and management; redesign, rebuilding, or relocation of capital assets; protection of beaches, dunes and maritime infrastructure; development zone control; and retreat plans.

In recent years RIAG has developed a statistical model to assess severe wind hazard in the non-cyclonic regions of Australia ('Region A' as defined in the Australian/NZ Standards for Wind Loading of Structures (AS/NZS 1170.2, 2002)). The model has been tested using observational data from wind stations located in South Eastern Australia. The statistical model matched the results of the Australian/NZ standard for wind loading of structures utilising a more efficient, fully computational method (Sanabria & Cechet, 2007a). We present a methodology to assess severe wind hazard in Australia for regions where there are no observations. The methodology uses simulation data produced by a high resolution regional climate model in association with empirical gust factors. It compares wind speeds produced by the climate model with observations (mean wind speeds) and develops functions which allow wind engineers to correct the simulated data in order to match the observed mean wind speed data. The approach has been validated in a number of locations where observed records are available. In addition a Monte-Carlo modelling approach is utilised to relate extreme mean wind speeds to extreme peak gust wind speeds (Sanabria & Cechet, 2007b).

Understanding marine biodiversity has received much attention from an ecological and conservation management perspective. For this purpose, scientific marine surveys are necessary and often conducted by a multidisciplinary team. In particular, the data collected can come from multiple sources inheriting a particular aspect of each discipline that requires reasonable integration for the purpose of modelling biodiversity. This talk gives an overview of some strategies investigated in the Marine Biodiversity Research Hub project funded by the Commonwealth Environment Research Facilities Program to reconcile these differences.

U-PB-HF-O CHARACTER OF NEOARCHAEAN BASEMENT TO THE PINE CREEK OROGEN, NORTH AUSTRALIAN CRATON