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  • This dynamic dataset is composed of data layers representing the potential damage arising from the impacts of Tropical Cyclone (TC) related winds on residential houses. The impacts are determined using information on the forecast track of the TC issued by the Bureau of Meteorology, nationally consistent exposure (residential building) and vulnerability (likely level of damage) information maintained by Geoscience Australia. The tracks are based on the content of Technical Bulletins issued by the Bureau of Meteorology’s Tropical Cyclone Warning Centres every 6 hours for active TCs in the Australian region. As such, information is generated intermittently, depending on the occurrence of TCs. The tracks are a forecast only, so do not include past position information of the TC. Forecasts may extend up to 120 hours (5 days) ahead of the forecast time. A wind field around each track is simulated using Geoscience Australia’s Tropical Cyclone Risk Model (TCRM, https://pid.geoscience.gov.au/dataset/ga/77484). This provides an estimate of the maximum gust wind speed over open, flat terrain (e.g. airports). Local effects such as topography and land cover changes are incorporated via site wind multipliers (https://pid.geoscience.gov.au/dataset/ga/75299), resulting in a 0.2-second, 10-m above ground level wind speed, with a spatial resolution of approximately 30 metres. The impacts are calculated using Geoscience Australia’s HazImp code (https://pid.geoscience.gov.au/dataset/ga/110501), which utilises the National Exposure Information System building data and a suite of wind vulnerability curves to determine the level of damage sustained by individual buildings (a damage index). The damage index values are aggregated to Australian Bureau of Statistics Statistical Area Level 1 regions, and can be assigned a qualitative damage description based on the mean damage index.

  • Windstorms cause most of the damage to housing in Australia. Population growth is exposing more people and buildings to risks from these wind hazards. Houses and components are currently designed and built to standards aligned with the Building Code of Australia. Regulatory measures including building inspections are meant to ensure acceptable quality of construction. Inspections and post windstorm damage surveys have consistently shown that contemporary houses (post 1980) perform better than older houses (pre 1980) in cyclone and non cyclone areas. However, errors in design and construction found during recent surveys, reduce the resilience of contemporary housing. Geoscience Australia is developing a software tool for assessing the vulnerability of housing, using empirical models, expert opinion, and engineering methods. These models could be used to assess vulnerability of a range of house types and also recommend adaptation measure to account for increases in the intensity of windstorms in Australia.

  • The National Hazard Impact Risk Service for Tropical Cyclone Event Impact provides information on the potential impact to residential separate houses due to severe winds. The information is derived from Bureau of Meteorology tropical cyclone forecast tracks, in combination with building location and attributes from the National Exposure Information System and vulnerability models to define the level of impact. Impact data is aggregated to Statistical Area Level 1, categorised into five qualitative levels of impact.

  • Modelling the effectiveness of retrofit to legacy houses requires a quantitative estimate of the houses’ vulnerability to severe wind and how the vulnerability is affected by mitigation work. Historical approaches to estimating vulnerability through either heuristic or empirical methods do not quantitatively capture the change in vulnerability afforded by mitigation. To address this information gap the Bushfire and Natural Hazards CRC project “Improving the Resilience of Existing Housing to Severe Wind Events” has augmented a software tool which models damage from wind loads and associated repair cost. In this paper the development process is described including the establishment of a suite of test cases to assess the effectiveness of the software. An example of the validation work is presented along with the augmentation of the software from the previous version. Finally, use of the software in assessing the incremental effectiveness of a range of mitigation strategies in economic terms is described. Abstract submitted to/presented at the19th Australasian Wind Engineering Society Workshop.

  • Australian Community Climate and Earth-System (ACCESS) Numerical Weather Prediction (NWP) data is made available by the Bureau of Meteorology for registered subscribers such as GA. ACCESS-C3 (City) model is a forecast-only model performed every 6 hours and consists of grid coordinates covering domains around Sydney, Victoria and Tasmania, Brisbane, Perth, Adelaide and Darwin. ACCESS Impact Modelling (ACCESS-IM) System utilise information from ACCESS-NWP on the forecast wind gust speeds ground surface (single-level) at 10 metres, simulated by the ACCESS-C3 model, for the time period of 0-12, 12-24, 24-36, 0-36.

  • The extensive electricity transmission network of Queensland is managed by Powerlink and has a significant exposure to both thunderstorms and tropical cyclones. In coastal North Queensland tropical cyclones (TC) dominate the severe wind hazard environment whereas in South East Queensland both storm types contribute significantly. Some parts of Powerlink’s network have high concentrations of older tower assets such as in the Gladstone region which supply electricity for the smelting and refining of aluminium. Other parts provide vital transmission links with limited redundancy between regions of generation in the south to large communities to the north, such as in far-North Queensland. These assets have been developed over many years, to design standards that have progressively changed, and some have been exposed to corrosive environments that are characteristic of the warm and humid coastal tropics. As a consequence of these factors, some assets within the system are particularly vulnerable to severe wind.

  • The Risk and Impact Analysis Group (RIAG) at Geoscience Australia (GA) in Canberra is a multidisciplinary research team. Their key role is to develop knowledge on the risk from natural and human-caused hazards for input to policy and operational decision makers for the mitigation of risk to Australian communities. The RIAG achieves this through the development of computational methods, models and decision support tools that assess the hazard, vulnerability and risk posed by hazards. The RIAG also works with other agencies to develop and collect information on natural disasters that is essential for developing valid risk models for forecasting the impact of future hazard events. The Group includes hazard experts, numerical modellers, engineers, economists, and GIS specialists. This paper will discuss the risk analysis process used at GA, with a particular focus on the vulnerability component. Earthquake and tsunami risk examples will highlight technical aspects of the work and step through the risk analysis framework that has been adopted. The method being used to develop vulnerability models for the wind and tsunami hazard is an engineering model approach. The method requires a generalised hazard definition, an engineering model of a particular structure, and a costing module to calculate the real cost of repairs. The initial focus will be Australian residential structures. The engineering model is based on the assumption that connection failure is the primary initiator of structural failure in residential structures (as opposed to say, a beam or wall stud failing in bending). It also assumes that component failures can be aggregated up into overall damage scenarios. The engineering model employs a Monte Carlo simulation approach that allows for the incorporation of variability (in connection strengths, building orientation, opening sizes, and key hazard parameters). The engineering model approach also allows the opportunity to investigate mitigation options through strengthening structural components. The multi-hazard risk approach used at GA is a move towards being able to make informed decisions on how to manage the risk from natural hazards. This paper has presented examples of computational natural hazard risk with a particular focus on the development of engineering vulnerability models. Presented at the International Forum on Engineering Decision Making, 12th to 15th Dec, 2007, Port Stephens, NSW.

  • Natural disasters provide an invaluable opportunity to capture data for improving our understanding of risk. Observed damage types and their predominance provide useful insights into the factors contributing to building vulnerability and consequential community risk. They also facilitate the appraisal of mitigation measures directed at reducing that risk where it is found to be high. Survey activities that followed the impact of Tropical Cyclone Larry have highlighted the benefits of a co-ordinated survey response to natural hazard impacts. The response to this event involved liaison with local emergency management and the broad participation of recognised wind engineering experts. Survey techniques were refined to achieve a more efficient and comprehensive approach that ensured consistency, utility and transferability of the data for all collaborators. The refined approach proved very successful and may provide a useful model for similar post-disaster exercises directed at earthquake damage. The sudden nature by which earthquakes inflict damage without warning points to having arrangements already established beforehand for the best survey outcomes. Proposals for advancing such preplanning are presented.

  • A presentation delivered at the Australia Reinsurance Pool Corporation / Organisation for Economic Co-operation and Development (ARPC/OECD) Terrorism Risk Insurance Conference held in Canberra from 6-7 October 2016. The presentation focusses on GA's work with the ARPC in developing a capability to estimate insured losses due to blast in Australian cities.

  • <div>Knowledge of the nature of buildings within CBD areas is fundamental to a broad range of decision-making processes, including planning, emergency management and the mitigation of the impact of natural hazards. To support these activities, Geoscience Australia has developed a building information system called the National Exposure Information System (NEXIS) which provides information on buildings across Australia. Most of the building level information in NEXIS is statistically derived, but efforts are being made to include more detailed information on the nature of individual buildings, particularly in CBD areas. This is being achieved in Perth through field survey work.</div>