The development of the National Exposure Information System (NEXIS) is a significant national project being undertaken by Geoscience Australia (GA). NEXIS collects, collates, manages and provides the information required to assess multi-hazard impacts. Exposure information is defined as a suite of elements at risk from a hazard which includes human populations, buildings, businesses and infrastructure. Understanding population exposure is essential for emergency planning and management. However exposure information can also be used for understanding climate change risk, assessing energy efficiency policy, urban planning and other spatial research. This paper focuses on the population aspects of NEXIS and recent work on estimation methods for the present day over any geographic extent. Plans for work on small area population estimates to 2100 will also be presented. Finally planned future work on activity modelling, that is determining population movement throughout the day, will also be highlighted.

This report covers the work carried out by the author who was the geophysicist in charge of seismic and magnetic work conducted on Macquarie Island during 1951-52. It deals mainly with the preparation of and repairs to huts, the continuation of the seismic recording programme and the installation of a magnetic recorder. Although scientific achievement was not outstanding, the way has been prepared for a successful observing programme in the future.

The Swan River is the main river through Perth, the capital city of Western Australia. Direct tangible economic losses to residential dwellings in Perth was based on hydraulic modelling using the one dimensional unsteady flow model HEC-RAS, geographical information systems, a building exposure database and synthetic stage-damage curves. Eight flood scenarios ranging from the 10 year average recurrence interval (ARI) to the 2000 year ARI event were examined. The combined structure and contents flood losses ranged from A$17 million to A$659 million for insured structures and A$14 million to A$583 million for uninsured structures. This equates to an average annual damage of A$9.6 million and A$7.9 million respectively. The results reinforce the need to consider a wide range of varying magnitude flood events when assessing losses due to the temporal and spatial variation between flood scenarios.

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.

<div>National Exposure Information System (NEXIS) Residential Dwelling Density is a set of four raster layers representing the density of residential dwellings across Australia at different scales and resolutions. A dwelling is defined 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. NEXIS collates the best publicly-available information, statistics, spatial and survey data into comprehensive and nationally-consistent exposure information datasets. Where data is limited, models are used to apply statistics based on similar areas. Exposure Information products are created at the national, state or local level to understand the elements at risk during an event or as a key input for analysis in risk assessments. NEXIS products are not intended for operational purposes at the building or individual feature level. Its strength is to provide consistent aggregated exposure information for individual event footprints or at standard community, local, state and national geographies such as the Australian Bureau of Statistics (ABS) Statistical Areas (SA) or Local Government Areas (LGA). NEXIS Building exposure information consists of Residential, Commercial and Industrial buildings. This information can be used to understand the type, use, age and structural characteristics such as number of storeys, roof type and wall type of the building stock nationally. Building exposure information can also be used to estimate population attributes such as the number of occupants, household income and other demographic indicators, as well as economic impacts based on building construction and replacement costs. The NEXIS Residential Dwelling Density is a national grid-based representation derived from the number and distribution of dwellings produced from the NEXIS residential buildings data. </div><div><br></div><div>Dwelling density is available as a web service displaying the aggregate number of dwellings, at four different raster scales and resolutions, to show the distribution and density of residential dwellings across Australia. Resolutions include 100m, 500m, 1km and 2km rasters.</div><div><br></div><div>Resolutions:</div><div>1. Number of residential dwellings per 100sqm. Visible at zoom scales 1:250,000 minimum with no maximum. </div><div>2. Number of residential dwellings per 500sqm. Visible at zoom scales 1:700,000 minimum with 1:250,001 maximum.</div><div>3. Number of residential dwellings per 1km square. Visible at zoom scales 1:3,000,000 minimum with 1:700,001 maximum. </div><div>4. Number of residential dwellings per 2km square. Visible at zoom scales with no minimum and 1:3,000,001 maximum</div><div>&nbsp;</div><div>This product is based on NEXIS version 15 (2024) data.</div><div><br></div>

A field party from the Bureau of Mineral Resources left Melbourne on 19th March, 1949, together with a relief party from the Australian National Antarctic Research Expedition. The objects of the party's visit to Macquarie Island were the establishment of a Seismological Observatory, the determination of the secular variation of magnetic declination, and the location of magnetically suitable areas for a proposed Magnetic Observatory. The present preliminary report is concerned exclusively with an accident which occurred during the construction of the Seismological Observatory and which caused injuries to A.B. Billan, R.A.N. The building plans and choice of the site are discussed.