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  • Exposure refers to the elements at risk which may be subjected to the impact of severe hazards within a defined geographic area or region. These elements include the built environment, i.e buildings, infrastructure services and utilities, and also population and business activity. Geoscience Australia (GA) is developing the National Exposure Information System (NEXIS) as a national capability to provide an exposure profile to underpin analysis of natural hazards; potential disaster footprints, risk assessments and climate change adaptation research. The NEXIS capability enables modelling to gain a greater understanding of the impact and risk exposure to these events. The information is used to inform evidence based decision making and future planning to aid in the prevention, preparedness, response and recovery to severe hazard events and climate change adaptation. The current NEXIS database provides exposure profile on building type, building construction materials (roof and wall), number of floors, floor area, year built and population demographics, business activity (turnover) and employee numbers. NEXIS is a demonstrated capability used in response to Tropical Cyclone Yasi, Victoria Bushfires, Queensland Floods and other recent national disaster events. The database also provides input data for use with the Earthquake Risk Model (EQRM) and Tropical Cyclone Risk Model (TCRM) to estimate direct and indirect losses to the built environment and possible population casualities. Further development of the database is planned to incorporate infrastructure and facilities data to enhance the capability and availability of nationally consistent data and exposure information.

  • Short article describing detection of interpreted unconformity between Coolbro Sandstone and Rudall Complex rocks near the Kintyre uranium deposit, Western Australia

  • Climate change is expected to exacerbate a range of natural hazards in Australia leading to more severe community impacts in the future. There is a need to adapt to a changing hazard environment and increasing community exposure in regions most likely influenced by climate change. Through this paper GA develops a methodology for projecting Australian communities in a spatial sense into the future. The application of this methodology is demonstrated in a case study. In order to address the fact that the impacts of climate change are expected to be more evident in the second half of this century, this model was to extend beyond the 30 year limitation of finer scale population projections, dwelling projections and development plans.

  • The Australian National Coastal Vulnerability Assessment (NCVA) has been commissioned by the Federal Government (Department of Climate Change) to assess the risk to coastal communities from climate related hazards. The first-pass national assessment includes an evaluation of the exposure and risk for infrastructure (currently only residential buildings) to severe wind gusts from tropical cyclones, which chiefly affect the northern part of the Australian continent. The understanding of the vulnerability and risk from cyclonic winds is derived from a number of factors, including: the frequency and intensity of the hazard, community exposure and the relationship between gust wind speed and impact/loss associated with residential structures. Cyclonic wind hazard along Australia's northern coastline has been estimated using Geoscience Australia's Tropical Cyclone Risk Model, utilising synthetic tropical cyclone event sets derived from IPCC AR4 global climate models. The wind hazard levels have been modified for terrain, topographic and shielding effects to reflect localised variations in wind hazard. The resulting hazard maps depicting annual exceedance probabilities for severe wind gusts have been integrated with Geoscience Australia's National Exposure Information System (NEXIS) to provide an analysis of impact, in terms of residential infrastructure affected and the cost of replacement. Australian Bureau of Statistics (ABS) population projections have been related to infrastructure/building projections via logical assumptions (residential buildings only) allowing the analysis of exposure to the end of the 21st century.

  • Severe wind is one of the major natural hazards in Australia. The main contributors to economic loss in Australia are tropical cyclones, thunderstorms and sub-tropical (synoptic) storms. Geoscience Australia's Risk and Impact Analysis Group (RIAG) is developing mathematical models to study a number of natural hazards including wind hazard. This study examines synoptic wind hazard under current and future climate scenarios using RIAG's synoptic wind hazard model. This model can be used in non-cyclonic regions of Australia (Region A in the Australian-New Zealand Wind Loading Standard; AS/NZS 1170.2:2002) which are dominated by synoptic and thunderstorm winds. The methodology to study synoptic wind hazard involves a combination of three models: - a statistical model (ie. a model based on observed data) to quantify wind hazard using extreme value distributions; - a technique to extract and process wind speeds from a high-resolution regional climate model (RCM), which produces gridded hourly 'maximum time-step mean' wind speed and direction fields; and - a Monte Carlo method to generate gust wind speeds from the RCM mean winds. Gust wind speeds are generated by a numerical convolution of the modelled mean wind speed distribution and a distribution of observed 'regional' gust factor. To illustrate the methodology, wind hazard calculations under current and future climate conditions for the Australian state of Tasmania will be presented. The results show increases in synoptic wind hazard in some parts of the state especially at the end of this century.

  • A review commissioned by the Council of Australian Governments (COAG) in June 2001 entitled 'Natural Disasters in Australia: reforming mitigation, relief and recovery arrangements' concluded that a new approach to natural disasters in Australia was needed. While disaster response and reaction plans remain important, there is now a greater focus towards anticipation of mitigation against natural hazards, involving a fundamental shift in focus beyond relief and recovery towards cost-effective, evidence-based disaster mitigation. This new approach now includes an assessment of the changes in frequency and intensity of natural hazard events that are influenced by climate change, and aims to achieve safer, more sustainable Australian communities in addition to a reduction in risk, damage and losses from future natural disasters. Geoscience Australia (GA) is developing risk models and innovative approaches to assess the potential losses to Australian communities from a range of sudden impact natural hazards. GA aims to define the economic and social threat posed by a range of rapid onset hazards through a combined study of natural hazard research methods and risk assessment models. These hazards include earthquakes, cyclones, floods, landslides, severe winds and storm surge/tsunami. This presentation provides an overview of the risk that peak wind gusts pose to a number of Australian communities (major capital cities), and for some cities examines how climate change may affect the risk (utilising modelling underpinned by a small subset of the IPCC greenhouse gas emission scenarios).

  • In addition to the devastating 1989 Newcastle earthquake, at least four other earthquakes of magnitude 5 or greater have occurred in the surrounding Hunter region since European settlement in 1804. Some of these earthquakes caused damage in areas that, at the time, were sparsely populated. Similar events, were they to occur today in populated areas, would certainly cause significant damage. The frequency with which these events have occurred in the Hunter region suggests that earthquakes pose a genuine threat to the communities there. This study presents the most comprehensive and advanced earthquake risk assessment undertaken for any Australian city to date. It has focused on the economic losses caused by damage to buildings from earthquake ground shaking, and not on the impacts from other, secondary hazards such as soil liquefaction and surface faulting. The study has adopted a probabilistic approach that makes allowances for the variability that is inherent in natural processes as well as the uncertainty in our knowledge. The results from this project will assist decision-makers involved in local and state government, policy development, the insurance industry, engineers, architects, and the building and finance industries to manage potential damage and loss of life from earthquakes in Newcastle and Lake Macquarie. The results also have implications for the earthquake risk facing larger Australian cities such as Sydney, Melbourne and Adelaide. This is due to a number of factors, including similarities between the earthquake hazard in Newcastle and Lake Macquarie and other parts of Australia, and similarities between the urban environments, particularly the composition of the building stock.

  • This is a short and informative 3.3 minute movie for the Engineering, Economics and Exposure Project - NEXIS Development for DCCEE - late 2010. It is a promotional movie that demonstrates NEXIS capabilities, and explains how NEXIS will be benefitial to the NEXIS stakeholder. This movie may also go onto the web, where it's purpose is to convince the public that NEXIS is a worthwhile investment in Australia's future.

  • Manila is one of the world's megacities, and the Greater Metro Manila Area is prone to natural disasters. These events may have devestating consequences for individuals, communities, buildings, infrastructure and economic development. Understanding the risk is essential for implementing Disaster Risk Reduction programs. In partnership with AusAID, Geoscience Australia is providing technical leadership for risk analysis projects in the Asia-Pacific Region. In the Philippines, Geoscience Australia is engaging with Government of the Philippines agencies to deliver the "Enhancing Risk Analysis Capacities for Flood, Tropical Cyclone Severe Wind and Earthquake in the Greater Metro Manila Area" Project.

  • We describe a weighted-average approach for incorporating various types of data (observed peak ground motions and intensities, and estimates from ground motion prediction equations) into the ShakeMap ground motion and intensity mapping framework. This approach represents a fundamental revision of ShakeMap technique, particularly as it pertains to processing ground motion and intensity data. Combining ground motion and intensity data onto composite ShakeMaps proves invaluable for loss calibration of historical events as well as for loss estimation in near-real time applications. In addition, the increased availability of near-real-time macroseismic intensity data, the development of new relationships between intensity and peak ground motions, and new relationships to directly predict intensity from earthquake source information, have facilitated the inclusion of intensity measurements directly into the ShakeMap computations. Our approach allows for the possible combination of all of the following data sources and estimates: 1) nearby observations (ground motion measurements and reported intensities), 2) converted observations from intensity to ground motion (or vice-versa), and 3) estimated peak ground motions from prediction equations (or numerical estimates).