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Climate change is expected to increase severe wind hazard in many regions of the Australian continent with consequences for exposed infrastructure and human populations. The objective of this study is to provide a nationally consistent assessment of wind risk under current climate and to provide preliminary indications of the effects (impact) of future hazard under several climate change scenarios. This is being undertaken by considering wind hazard, infrastructure exposure and wind vulnerability of infrastructure (residential buildings). The National Wind Risk Assessment (NWRA) will identify communities subject to high wind risk under present climate, and which will be most susceptible to any climate change related exacerbation of local wind hazard. While there is significant uncertainty on what the likelihood of extreme winds will be in the future, the understanding of current local wind hazard for the Australian region is also in need of improvement. Australian wind hazard is based on the statistical analysis of extreme wind observations and engineering judgement. Observations include peak 3-second gusts captured at about 30 meteorological measurement stations, mainly located at significant city and regional airports. These provide poor spatial texture with regard to wind hazard. This study is taking advantage of modelled wind hazard assessments (current climate) being developed at Geoscience Australia utilising separate techniques for the three main wind hazards: tropical cyclones; thunderstorms; and synoptic winds. A stochastic model based on observed and modelled cyclone tracks is used to obtain an understanding of cyclonic wind hazard, whilst two statistical approaches involving observed and modelled vertical instability and mean wind speed fields (via high-resolution regional climate model) are the basis for the thunderstorm and synoptic wind hazard.
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This booklet identifies different types of volcanoes, and the dangers associated when volcanic materials are ejected in an eruption. It explains the importance of why we should study volcanoes and the effects these eruptions have on the atmosphere and climate. It also identifies where volcanoes are located in Australia. Student activities are included.
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Geoscience Australia (GA) embarked on the development of the National Exposure Information System (NEXIS) project in response to the Council of Australian Governments (COAG) reform commitment on Australia's ability to manage natural disasters and other emergencies. The COAG commitment was for the establishment of a nationally consistent system of data collection, research and analysis to ensure a sound knowledge base on natural disasters and disaster mitigation - (DOTARS 2002). NEXIS has also been identified as an important component for improving several projects of national interest within Geoscience Australia (GA). These include the Risk Analysis Methods Section (RAMS), Climate hazards and Risk Section (CHRS) and the Vulnerability Section (VS) which investigate natural and man-made risks and their impacts on the community. The NEXIS was developed by the Exposure Information Section (EIS), National Geographic Information Group (NGIG), formerly the Engineering, Economic and Exposure Project (E3P), Risk and Impact Analysis Group (RIAG), within Geoscience Australia. It has a key role to gather accurate and up-to-date exposure information about Australia's resident population and buildings. This information is used when calculating the risk from natural and man-made disasters in order to inform policy and operational decision makers of the impact on Australian communities. In order to understand the effects a natural or man-made disaster could have on a community we need to know as much as we can about the people and buildings that occupy that area. This includes information about: People: how many people will be affected and where they live Buildings: the type of construction materials used, the number of storeys, and age all contribute to how a building withstands damage Cost : how much will it cost to rebuild a house or replace contents if damaged This information is used to not only investigate physical impacts of a disaster, but also forms base information that is needed to help inform the socio-economic impacts, such as loss to the business community when impacted by severe cyclonic wind storms. The National Exposure Information System (NEXIS) aims to maintain building level detail for all residential, commercial and industrial building in Australia. NEXIS information is available at Local Government Are (LGA) & Statistical Local Area (SLA)
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Introduction The Rapid Inventory Collection System (RICS) was initially conceived as a roving vehicular video damage assessment platform which offered many potential time and cost saving benefits to Geoscience Australia (GA) in the efficient and effective assessment of building and infrastructure damage following natural disasters. In particular, RICS: - provides a quick 'first-look' of the damage impact area when the first-on-scene personnel are assessing worst-hit regions - compliments and augments the detailed field damage assessments (house-to-house, structure-to-structure) currently undertaken using hand-held PDAs - allows for 100% coverage of building damage in a disaster-affected area - collects data focusing on 'population coverage' and undamaged structures allowing key engineering and geographic information systems (GIS) staff to focus on damaged structures - allows the field damage assessment to be undertaken more efficiently and in a shorter period of time - provides the option of analysing data off site when operating in the field in 'poor weather conditions' and - is useful for rapid building inventory assessment, validation & updating To date, RICS has been mainly utilised for building inventory assessment in support of the development of the National Exposure Information System (NEXIS), a buildings database that GA is constructing for national scale infrastructure risk assessment.
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Palaeotsunami investigations can enhance our understanding of tsunami hazard in the Australian region, providing a means of assessing future risk. Previous researchers have suggested that at least six large tsunami impacted the NSW coast during the Holocene, some with run-up in excess of +100 m asl and inundation of 10 km inland. However, this evidence is contentious as it focuses on poorly understood rocky shoreline features and proposes tsunami signatures that have not been described in other parts of the world. If such evidence is substantiated, it has profound implications for the tsunami preparedness of the NSW communities. This study focuses on late Holocene coastal sedimentary records from backshore environments in NSW to develop an assessment of whether catastrophic marine inundation such as tsunami played a significant role in coastal evolution. The advantages of studying backshore environments are that a more continuous sedimentary record is likely to be preserved than on rocky shorelines and an estimate of tsunami recurrence can be obtained if several tsunamigenic units are found in sequence. Fifty cores from sixteen coastal water bodies in southern and central NSW were studied for evidence of past tsunami inundation. Potentially tsunamigenic sediment horizons were identified in some water bodies, which may be a result of localised submarine slump-induced palaeotsunami. However the small size and discontinuous distribution of these sedimentary units does not support the theory of "mega-tsunami" inundation. If such "mega-tsunami" had occurred, definitive evidence for them should be preserved on a wider scale in the backshore sedimentary record. This suggests that previous research for mega-tsunami on the NSW coastline needs to be re-evaluated.
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We have applied new modelling and analysis techniques to develop a revised understanding of the regional wind hazard across the Tasmanian region. This modelling builds on downscaled global climate simulations from the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) over the Tasmanian region, undertaken by the Climate Futures for Tasmania project. These downscaled simulations enabled the development of wind hazard maps for the Tasmanian region both for current climate and also for two climate change scenarios. The wind hazard assessments (current and future climates) were used in a wind risk model to investigate the impact of severe wind risk on residential buildings. Australian Bureau of Statistics population projections were used to scale-up the number of residential structures based on the current ratio of residents per structure. The assessment of wind risk driven by the small increase in the hazard during the 21st century resulted in little or no change to the wind risk associated with the current residential building stock. When population projections were utilised to infer increased number of buildings (all built to the present building code), the proportion of legacy buildings within the building population declined resulting in a decline in wind risk. Wind risk levels remain well below those experienced in the northern part of the Australian continent were high wind hazard, chiefly associated with tropical cyclones, results in risk much greater than that experienced in Tasmania.
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The impacts of climate change, including sea level rise and the increased frequency of storm surge events, will adversely affect infrastructure in a significant number of Australian coastal communities. In order to quantify this risk, Geoscience Australia in collaboration with the Department of Climate Change and Energy Efficiency, have undertaken a first-pass national assessment which has identified the extent and value of infrastructure that are potentially vulnerable to impacts of climate change. We have utilised the best available national scale information to assess the vulnerability of Australia's coastal zone to the impacts of climate change. In addition to assessing coastal vulnerability assuming the current population, we also examined the changes in exposure under a range of future population scenarios provided by the Australian Bureau of Statistics. Continuation of the current trend for significant development in the coastal zone increases the number and value of residential buildings potentially vulnerable by 2100. We found that over 270,000 residential buildings are potentially vulnerable to the combined impacts of inundation and recession by 2100. This equates to a replacement value of approximately AUD$72 billion. Nearly 250,000 residential buildings were found to be potentially vulnerable to inundation only, which equates to AUD$64 billion. Queensland and New South Wales have the largest vulnerability (considering both value and number of buildings affected). Nationally, approximately 33,000 km of road and 1,500 km of rail infrastructure are potentially at risk by 2100. These results are influencing policy and adaptation planning decisions made by federal, state and local government.
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AUSTRALIAN MULTI-HAZARD RISK RESEARCH TO INFORM MITIGATION John Schneider, Mark Edwards, Trevor Jones, Bob Cechet, Trevor Dhu, Ole Nielsen, David Robinson, David Burbidge, Jane Sexton, Krishna Nadimpalli Risk & Impact Analysis Group, Geoscience Australia GPO Box 378, Canberra, ACT 2601, Australia, john.schneider@ga.gov.au The annual cost of sudden onset natural hazards in Australia was estimated in 2001 to be more than 1.1 billion Australian dollars, and the cost of events since then indicates that ongoing efforts are required to manage the risks from a range of hazards. Tropical Cyclone Larry which impacted North Queensland (March 2006) and the Hunter Valley floods (June 2007) are the latest events to have each caused more than a billion dollars of insured and uninsured damage. They have also triggered substantial government relief payments. In 2003 the Council of Australian Governments (COAG) published a review of natural disaster relief and mitigation arrangements in Australia. Significantly, the review recommended the development and implementation of a "national program of systematic and rigorous disaster risk assessments". The report advocated a fundamental shift in focus from response to cost-effective, evidence-based disaster mitigation. As a result, the Natural Disaster Mitigation Programme (NDMP) was implemented by the Australian Government in collaboration with the State and Territory Governments. The aim of the NDMP was to reduce the costs of natural disasters in Australia by supporting risk assessment and mitigation efforts. Geoscience Australia has been engaged as a technical advisor as part of the programme and has also undertaken a series of national risk assessments for a range of natural hazards. Geoscience Australia has also facilitated the development of a national risk assessment advisory structure and risk assessment framework. Significant progress has been made in developing methods, models and tools for application to impact and risk assessment studies. In this presentation we examine three risk/impact assessment models and associated case studies for earthquake, cyclone/severe wind and tsunami. Each risk/impact model consists of hazard, building and population exposure, and consequence/damage modules. The hazard component considers the probability of occurrence of events of different magnitudes (or categories) and locations, and the propagation of energy from the hazard source to sites of interest. The exposure information is provided by the National Exposure Information System (NEXIS), which captures key attributes of residential and commercial buildings, critical infrastructure, population statistics, and business activity information. Vulnerability models consider the relationship between hazard exposure and the resulting damage to buildings/infrastructure, and human casualties. Underpinning research has been directed at developing vulnerability models applicable to Australian infrastructure and has drawn upon several surveys of extreme event damage. Building damage is then linked to repair-cost models that have been developed using quantity surveying data. Finally, the costs and repair times are used to evaluate direct and indirect economic impacts at a regional and national scale. The economic assessment has entailed the spatialisation of the disruption of essential utility services to urban communities well outside the footprint of damage. Geoscience Australia is making these risk/impact assessment models and information available to the States and Territories and other stakeholders. This is being done through the release of open source software, interoperable databases, web-based information access, and the training of technical experts.
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The short historical record of tropical cyclone activity in the Australian region is insufficient for estimating return period wind speeds at long return periods (greater than 100 years). Utilising the auto-correlated nature of tropical cyclone behaviour (forward speed and direction, intensity and size), Geoscience Australia has developed a statistical-parametric model of tropical cyclone behaviour to generate synthetic event sets that are statistically similar to the historical record. The track model is auto-regressive, with lag-1 auto-regression used for forward speed and bearing, and lag-2 auto-regression applied to the intensity and size characteristics. Applying a parametric wind field and a linear boundary layer model to the synthetic tropical cyclone tracks allows users to generate synthetic wind swaths, and in turn fit extreme value distributions to evaluate return period wind speeds spatially. The model has been applied to evaluate severe wind hazard across Australia and neighbouring regions. In conjunction with statistical models of synoptic (mid-latitude storms) and thunderstorm wind hazard, we have been able to generate a national assessment of severe wind hazard, which is comparable to existing wind loading design standards. Using tropical cyclone-like vortex tracks directly detected from regional climate models, it is also possible to project cyclonic wind hazard into future climate conditions, accounting for both changes in frequency and intensity of tropical cyclones.
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The Rapid Inventroy Collection System (RICS) is a vehicular data collection system (image and GPS) used for building/infrastructure damage and inventory assesment. The system consists of Ethernet Cameras attached to a tripod mounted on the roof of a motor vehicle, a GPS device, and software written in C++ and developed using the Agile software development methodology. RICS has been extensively field tested and is ready for deployment at short notice.