From 1 - 10 / 254
  • Geoscience Australia, in collaboration with the Department of Climate Change and Energy Efficiency (DCCEE), has conducted a preliminary study to investigate the risk posed to Australian communities by severe winds, both in the current climate and under a range of future climate scenarios. This National Wind Risk Assessment (NWRA) represents the first national-scale assessment of severe wind risk, using consistent information on residential buildings and severe wind hazard. The NWRA has produced an understanding of severe wind hazard for the whole Australian continent, including extreme winds caused by tropical cyclones, thunderstorm downbursts and synoptic storms. New modelling and analysis techniques have been applied to the results of Intergovernmental Panel on Climate Change (IPCC) climate modelling efforts to enable assessment of regional wind hazard to the end of the 21st century for four case study regions: Cairns, southeast Queensland, Hobart and Perth. In developing adaptation options, it is essential to have an understanding of the existing risk, and the risk at future times if no action is taken. Adaptation options can then be assessed on their cost versus benefit (i.e. reduction in risk). The NWRA presents methods by which the effectiveness of adaptation to improve residential building resilience may be assessed in economic terms. The study also recognises it is important that the outcomes of the risk analysis are communicated in such a way that the results are easily understood and utilised to support evidence-based policy.

  • The paper presents a methodology developed at Geoscience Australia to analyse the impact of tropical cyclone (TC) hazard on communities in northern Australia. This work was carried out for the Garnaut Climate Change Review commissioned by Australia's State and Territory Governments. The Review examined the impacts of, and possible policy responses to, climate change on the Australian economy The study focuses on the maximum potential intensity (MPI) of the wind hazard. This sets a thermodynamic, theoretical upper limit for the distribution of TC intensities given a vertical temperature and humidity profile and given location. Storm surge impacts were developed using a simple relationship between TC intensity and storm surge height and adopting the IPCC global mid-point sea-level rise predictions. We consider the impact on residential building stock of severe wind and storm surge hazards associated with a number of IPCC climate change scenarios. Changes in residential building stock, for over 500 coastal statistical local areas (SLA's) from Southeast Queensland anticlockwise to Perth, were forecast using Australian Bureau of Statistics population projections through to 2100. A Probable Maximum Loss (PML) curve for each study region was obtained. The average annual cost to the region due to exposure to tropical cyclones across a 5000 year period or 'annualised losses' were evaluated for each study region. Expressing the annualised loss as a percentage of total reconstruction demonstrates the intensity of the risk to the studied community not so evident in simple dollar loss figures. We show the projected population, especially the drift to coastal locations in Queensland, is significant in determining the damage associated with possible future cyclone threat.

  • FIRE NOTE 4 page article for the BCRC/AFAC information series.

  • Historical settlement patterns have resulted in Australia having most of its major city developments situated on the coastline. Storm tides are a major natural hazard for coastal regions. Severe storms and cyclones contribute 29 per cent of the total damage cost from natural hazards to the Australian community. In 1999 prices, this amounts to A$40 billion during the period 1967 to 1999 (including the cost of deaths and injuries). A storm surge is an increase in coastal water levels well above the normal high tide. If the storm surge is combined with daily tidal variation, the combined water level is called the storm tide. When the resulting storm tide exceeds the normal tidal range, local beach topography will dictate whether significant coastal inundation will occur.

  • Tsunamis are unpredictable and infrequent but potentially large impact natural disasters. To prepare, mitigate and prevent losses from tsunamis, probabilistic hazard and risk analysis methods have been developed and have proved useful. However, large gaps and uncertainties still exist and many steps in the assessment methods lack information, theoretical foundation, or commonly accepted methods. Moreover, applied methods have very different levels of maturity, from already advanced probabilistic tsunami hazard analysis for earthquake sources, to less mature probabilistic risk analysis. In this review we give an overview of the current state of probabilistic tsunami hazard and risk analysis. Identifying research gaps, we offer suggestions for future research directions. An extensive literature list allows for branching into diverse aspects of this scientific approach. Appeared online in Front. Earth Sci., 29 April 2021

  • One of the more important observations from the 1989 Newcastle earthquake in Australia was the spatial distribution of earthquake damage, which was strongly related to variability in near-surface regolith properties and their influence on ground-shaking (i.e. site response). This association between ground-shaking and sediment distribution is well recognised, but has not previously been investigated for much of Australia. In an effort to characterize the Australian regolith in terms of its ability to modify earthquake energy, this study develops a national site classification map of Australia for application in first order earthquake hazard and risk assessment. Site classes are assigned based on a method developed in California, which uses the relationship between geological material and the shear wave velocity of the upper 30 m (Vs30). The classification scheme is then adjusted to suit the Australian geological environment, by accounting for the presence of highly weathered in situ regolith commonly encountered in this generally stable tectonic setting. This methodology has been successfully tested using geophysical data from a variety of Quaternary sedimentary environments in the Newcastle, Sydney and Perth urban areas and from bedrock-dominated environments at a range of sites across Australia.

  • In this study, a methodology is developed to assess the vulnerability of individuals within households to risk from natural hazards. The methodology introduces a technique for measuring certain attributes of individuals living within a household that contribute to their vulnerability to a natural hazard impact. The methodology has four main steps; 1) indicator selection 2) a risk perception questionnaire 3) decision tree analysis 4) synthetic estimation. Step four involves an application to an area in Perth, Western Australia. The study found that, through the application of this new methodology, eleven unique combinations of specific attributes contribute to the vulnerability of an individual within a household. The attributes, referred to as vulnerability indicators, of most importance relate to various levels of; injury sustained, residence damage, house insurance, income and type of house ownership. This finding suggests that individual and household finances, when combined with other specific indicators, play a significant role in determining an individual's vulnerability to a natural hazard impact. The combinations of indicators can be mapped in order to provide a useful tool for representing aspects of social vulnerability to natural hazard impacts.

  • The seismicity of the Australian continent is low to moderate by world standards. However, the seismic risk is much higher for some types of Australian infrastructure. The legacy of older unreinforced masonry buildings, in particular, may contribute disproportionately to community risk. At 8:17am on the 20th April a Mw 5.0 earthquake shook Kalgoorlie. The resultant ground motion was found to vary markedly across the town with the older masonry building stock in the suburb of Boulder experiencing a greater shaking intensity than the corresponding vintage of buildings in the Kalgoorlie business district 4km away. The event has provided the best opportunity to examine the earthquake vulnerability of Australian buildings since the Newcastle Earthquake of 1989. This paper describes the event and the staged collaborative survey activity that followed. The initial reconnaissance team of two specialists captured street-view imagery of 12,000 buildings within Kalgoorlie using a vehicle mounted camera array developed by Geoscience Australia. This information subsequently informed a systematic population based building survey using PDA data collection units. The work was performed by a team of nine from the University of Adelaide, the University of Melbourne and Geoscience Australia. This paper describes the preliminary findings of the work and outlines proposed future research.

  • The influence of federalism, especially in the role of fiscal centralisation, has significantly shaped Australia's state and federal government approaches and management of natural disasters. A review of the political climate around the time Cyclone Tracy devastated Darwin in 1974 provides a significant insight into how the relationship between the Commonwelath and State Governments shaped the backbone of Australia's emergency management arrangements. This influence is still evident today and provides an ongoing challenge for achieveing long-term mitigation.