From 1 - 10 / 192
  • Some of the most visible consequences arising from climate change are sea level rise and more intense and frequent storms. On the open coast and low lying estuarine waterways these impacts will lead to the increased risks of inundation, storm surge and coastal erosion that can damage beaches, property and infrastructure and impact on a significant number of people. Understanding the potential risk of these coastal hazards is critical for coastal zone management and the formulation of adaptation responses, while early action is likely to be the most cost effective approach to managing the risk. Geoscience Australia (GA) is assisting the Australian Government's Department of Climate Change to develop a 'first pass' National Coastal Vulnerability Assessment. GA and the University of Tasmania (UTas) are developing fundamental spatial datasets and GIS modelling tools to identify which land areas of the Australian coast are likely to be physically sensitive to the effects of sea level rise, storms and storm surge. Of special interest is to identify sensitive areas where there is significant property and infrastructure that will be the focus of a more detailed study in a second pass assessment. A new national shoreline geomorphic and stability map or Smartline, developed for the project by UTas, is a key new spatial dataset. The Smartline is an interactive, nationally-consistent coastal GIS map in the form of a segmented line. Each line segment identifies distinct coastal landform types using multiple attribute fields to describe important aspects of the geology, geomorphology and topography of the coast. These data enable an assessment of the stability of the coast and its sensitivity to the potential impacts of shoreline erosion (soft coast) and inundation (low-lying coast), providing a useful indicative coastal risk assessment.

  • This framework is a reference for individuals and agencies involved in bushfire risk assessment in Australia who seek to improve information on bushfire risk from quantitative methods compared to qualitative methods. It is aimed at bushfire researchers and risk managers in fire, planning and related agencies. Computational bushfire risk assessment is in an early stage of development in Australia. It is an opportune time to establish a framework sufficiently broad that it will accommodate pre-existing and new methods to assess bushfire risk while encouraging innovation. Current methods for assessing bushfire risk in Australia use different terminologies and approaches, and application of an overarching framework improves the potential to compare methods and confidence in comparing results between studies.

  • 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 paper is to provide an initial nationally consistent assessment of wind risk under current climate, utilizing the Australian/New Zealand wind loading standard (AS/NZS 1170.2, 2002) as a measure of the hazard. This work is part of the National Wind Risk Assessment (NWRA), which is a collaboration between the Australian Federal Government (Department of Climate Change and Energy Efficiency) and Geoscience Australia. It is aimed at highlighting regions of the Australian continent where there is high wind risk to residential structures under current climate, and where, if hazard increases under climate change, there will be a greater need for adaptation. This assessment is being undertaken by separately considering wind hazard, infrastructure exposure and the wind vulnerability of residential buildings. The NWRA will provide a benchmark measure of wind risk nationally (current climate), underpinned by the National Exposure Information System (NEXIS; developed by Geoscience Australia) and the wind loading standard. The methodology which determines the direct impact of severe wind on Australian communities involves the parallel development of the understanding of wind hazard, residential building exposure and the wind vulnerability of residential structures. We provide the current climate wind risk, expressed as annualized loss, based on the wind loading standard.

  • Evidence based disaster management enables decision makers to manage more effectively because it yields a better informed understanding of the situation. When based on evidence, the decision making process delivers more rational, credible and objective disaster management decisions, rather than those influenced by panic. The translation of fundamental data into information and knowledge is critical for decision makers to act and implement the decisions. The evidence from appropriate information helps both tactical and strategic responses to minimise impacts on community and promote recovery. The information requirements of such a system are quite comprehensive in order to estimate the direct and indirect losses; the short and long term social and economic resilience. Disasters may be of rapid onset in nature like earthquakes, tsunamis and blast. Others are slow onset such those associated with gradual climate change. Climate change has become a real challenge for all nations and the early adaptors will reduce risk from threats such as increased strength of tropical cyclones, storm surge inundations, floods and the spread of disease vectors. The Australian Government has recognised the threats and prioritised adaptation as an opportunity to enhance the nation's existing infrastructure and thereby reduce risk. A thorough understanding of the exposure under current and future climate projections is fundamental to this process of future capacity building. The nation's exposure to these increased natural hazards includes all sectors from communities to businesses, services, lifeline utilities and infrastructure. The development of a National Exposure Information System (NEXIS) is a significant national capacity building task being undertaken by Geoscience Australia (GA). NEXIS is collecting, collating, managing and providing the exposure information required to assess multi-hazard impacts.

  • Extreme events in a changing climate A climate event is 'extreme' when it (or a series of events) occurs with greater intensity, frequency or duration than is normally expected. Every region of the world experiences extreme events from time to time and natural climate variability already produces extreme events in Tasmania. This includes heat waves, cold waves, floods, droughts and storms. Extreme events can have devastating and wide ranging effects on society and the environment, impacting infrastructure, agriculture, utilities, water resources and emergency planning.

  • This presentation will provide an overview of some of the work currently being undertaken at Geoscience Australia GA) as part of the National Coastal Vulnerability Assessment (NCVA), funded by the Department of Climate Change (DCC). The presentation will summarise the methodology applied, and highlight the issues, including the limitations and data gaps.

  • The Climate Futures for Tasmania (CFT) research project is the Tasmanian Government's most important source of climate change data at a local scale. The project has created fine-scale (14 kilometre) climate information for Tasmania by downscaling five global climate models (GCM-s) with two IPCC emission scenarios (A2 and B1) to generate climate information from 1961 to 2100. This new dataset is being used to interpret the impact of the changing climate on four main disciplines: General Climate, Water and Catchments, Extreme Events and Agriculture. As part of the extreme events component, Geoscience Australia is conducting severe wind hazard and risk studies in the Tasmanian region under both current and future climate conditions. In this paper we present severe wind hazard maps for Tasmania for current and future climate. The CFT fine scale climate simulations which provide high-resolution spatial detail of the wind speed (hourly maximum time-step mean wind speed used) were used. The methodology is described in an accompanying paper ('Dynamical downscaling of severe wind hazard: Methodology', in these proceedings).

  • Geoscience Australia has developed a model to assess severe wind hazard for large-scale numerical model-derived grided data. The severe wind modelling approach integrates two models developed at Geoscience Australia: a) A statistical model based on observations which determines return periods (RP) of severe winds using Extreme Value distributions (EVD), and b) A model which extracts mean wind speeds from high resolution numerical models (climate simulations) and generates wind gust from the mean speeds using Monte Carlo simulation (convolution with empirical gust factors) This methodology is particularly suitable for the study of wind hazard over large regions, and is being developed to provide improved spatial information for the Australia/NZ Wind Loading Standard (AS/NZS 1170.2, 2002). The methodology also allows comparison of current and future wind hazard under changing climate conditions. To illustrate the characteristics and capabilities of the methodology, the determination of severe wind hazard for a high-resolution grid encompassing the state of Tasmania (south of the Australian continent) will be presented and discussed, considering both the current and a range of possible future climate conditions (utilising IPCC B1 & A2 emission scenarios).

  • Overhead transmission lines are a key element of the electrical power system for transferring bulk power from generators to communities. Lattice type transmission towers carrying conductors form the physical backbone of the power transmission system. Transmission tower safety and reliability assessment is necessary to plan for minimisation of the risk of disruption of power supply resulting from in-service tower failure. Lattice type transmission towers are constructed using angle section members and are eccentrically connected. They are regarded as one of the most difficult forms of lattice structures to analyse for dynamic loads. Analysis is difficult due to fabrication errors, inadequate joint details and material properties being hard to quantify as a combination. Proof loading and full-scale tower testing is a traditional form of design validation for lattice type towers [1]. However, loading conditions experienced in severe wind events are dynamic and relatively short term loads and this behavior is confirmed in a limited way through full scale measurements of aero-elastic models in wind tunnels [2].