NEXIS (National Exposure Information System) Residential Dwelling Density is a set of four raster layers representing the density of residential dwellings across Australia at different scales and resolutions. Resolutions include 2km, 1km, 500m and 100m. The Australian Bureau of Statistics (ABS) defines dwelling units as self-contained suites of rooms including cooking and bathing facilities and intended for long-term residential use. Such dwelling units include houses-detached buildings used for long-term residential purposes-and other dwellings including flats. This product is based on NEXIS version 13 (2022) data.

The National Seismic Hazard Assessment (NSHA) is a flagship Geoscience Australia product, used to support the decisions of the Australian Building Codes Board Standards Subcommittee BD-006-11, to ensure buildings and infrastructure are built to withstand seismic events in Australia. The NSHA has been updated in 2018 and includes significant advances on previous assessments including: inclusion of epistemic uncertainty using third-party source models contributed by the Australian seismology community, use of modern ground-motion models, and more. As a consequence of these advances, estimates of seismic hazard have decreased significantly across most Australian localities at the return period (of earthquake ground shaking) currently used by the Australian Standard. The objective of this document is to outline the significant changes to the NSHA18 from the 2012 version, and the science behind these changes. The responses were developed through feedback and consultation with experts in the seismic and engineering industry. If you have additional questions, please contact the project team at hazards@ga.gov.au.

Report is result of a rapid geological reconnaissance of the Federal Territory made primarily to locate deposits of limestone and shale, suitable for the manufacture of Portland cement, and other materials likely to be of value in the building of the Federal City.

Indonesia is located in one of the most seismically active regions in the world and often experiences damaging earthquakes. In the past the housing sector has sustained more damage and losses than other sectors due to earthquakes. This is often attributed to the fact that the most common houses in Indonesia are non-engineered, built with poor quality workmanship, poor quality materials and without resilient seismic design features. However little effort has been made to quantify how fragile these houses are, or how the fragility of these houses may vary according to location or wealth. It is not possible to derive empirical fragility functions for Indonesia due to insufficient damage data. The aim of this study is to determine whether existing earthquake fragility functions can be used for common houses in Indonesia. Scenario damage analyses were undertaken several times using different sets of fragility functions for the 2006 Yogyakarta and 2009 Padang events. The simulated damage results were then compared to the damage observed post event to determine whether an accurate damage prediction could be achieved. It was found that the common houses in Yogyakarta and Central Java vary according to age, location and wealth and can be reasonably well represented by existing fragility functions. However, the houses in Padang and surrounding West Sumatra did not vary in a predictable manner and are more fragile than anticipated. Therefore, the fragility of the most common houses in Indonesia is not uniform across the country. This has important implications for seismic damage and risk assessment undertaken in Indonesia. <b>Citation:</b> Weber, R., Cummins, P. & Edwards, M. Fragility of Indonesian houses: scenario damage analysis of the 2006 Yogyakarta and 2009 Padang earthquakes. <i>Bull Earthquake Eng</i> (2024). https://doi.org/10.1007/s10518-024-01930-z

This paper presents a methodology for post-earthquake probabilistic risk (of damage) assessment that we propose in order to develop a computational tool for automatic or semi-automatic assessment. The methodology utilizes the same so-called risk integral which can be used for pre-earthquake probabilistic assessment. The risk integral couples (i) ground motion hazard information for the location of a structure of interest with (ii) knowledge of the fragility of the structure with respect to potential ground motion intensities. In the proposed post-mainshock methodology, the ground motion hazard component of the risk integral is adapted to account for aftershocks which are deliberately excluded from typical pre-earthquake hazard assessments and which decrease in frequency with the time elapsed since the mainshock. Correspondingly, the structural fragility component is adapted to account for any damage caused by the mainshock, as well as any uncertainty in the extent of this damage. The result of the adapted risk integral is a fully-probabilistic quantification of post-mainshock seismic risk that can inform emergency response mobilization, inspection prioritization, and reoccupancy decisions.

This web service shows areas or locations occupied by an existing high-density urban development or known individual building structures in peri-urban and remote locations. Data used in this service is of varying levels of coverage and quality since it is aggregated from a variety of sources. The intended purpose of the service is to provide preliminary, first-pass information about urban environment, building structures and their distribution in landscape, as one of constraints on future development. Users should carry out further and more detailed investigations because this information is not meant to be a definitive source or support engineering phase planning. The service has layer scale dependencies.

Geoscience Australia is the Australian Government advisor on the geology and geography of Australia, and develops the National Seismic Hazard Assessment (NSHA). The NSHA defines the level of earthquake ground shaking across Australia that has a likelihood of being exceeded in a given time period. Knowing how the ground-shaking hazard varies across Australia allows high hazard areas to be identified for the development of mitigation strategies so communities can be more resilient to earthquake events. The NSHA provides key information to the Australian Government Building Codes Board, so buildings and infrastructure design standards can be updated to ensure they can withstand earthquake events in Australia. Using the NSHA, decision makers can better consider: • What this could mean for communities in those areas and whether any further action is required • Where to prioritise further efforts • What this could mean for insurance and reinsurance premiums • Identify high and low hazard areas to plan for growth or investment in infrastructure

Knowledge of the nature of buildings within business precincts 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 business districts. This is being achieved in Southbank through field survey work.

Papua New Guinea (PNG) sits at complex boundary between three major tectonic plates and eight microplates. As a result of this setting, the region experiences significant seismic activity that gives the country a hazard that ranges from low in the south west of the country up to very high by global hazard levels found at plate boundaries. This hazard has been long recognised and the suite of building standards released in 1982 contain provisions to impart resilience to buildings that were based on the best understanding of seismic hazard available at that time. The associated design methodologies in the standards also embody design methodologies that reflect the then current seismic design practice including requirements for achieving structural ductility in design using a range of structural materials. With a bedrock hazard that varies across the country, the overall objective of the suite of standards is that the design provisions impart properly constructed buildings with a strength and toughness compatible with the local hazard severity.

Earthquake hazard was not fully recognised in Australian building design until the mid-1990's. This oversight has resulted in a legacy of vulnerable buildings that can be readily damaged in moderate to severe Australian earthquakes. In particular, older unreinforced masonry buildings are particularly vulnerable and very common in the centres of our large cities and towns with significant heritage value. What can be done to cost-effectively address the risk they represent to people in the community and to protect these valued assets from future damaging earthquakes? With a focus on the Heritage town of York and the state capital of Melbourne, strategies have been examined as to effectiveness which have included a virtual retrofit to progressively reduce damage, injury, economic losses and emergency management logistics. Communication products derived from this work are described and initiatives to apply them in other Australian communities highlighted.