From 1 - 10 / 138
  • The Historical Bushfire Boundaries service represents the aggregation of jurisdictional supplied burnt areas polygons stemming from the early 1900's through to 2022 (excluding the Northern Territory). The burnt area data represents curated jurisdictional owned polygons of both bushfires and prescribed (planned) burns. To ensure the dataset adhered to the nationally approved and agreed data dictionary for fire history Geoscience Australia had to modify some of the attributes presented. The information provided within this service is reflective only of data supplied by participating authoritative agencies and may or may not represent all fire history within a state.

  • Abstract: Land Surface Temperature (Ts) is an important boundary condition in many land surface modelling schemes. It is also important in other application areas such as, hydrology, urban environmental monitoring, agriculture, ecological and bushfire monitoring. Many studies have shown that it is possible to retrieve Ts on a global scale using thermal infrared data from satellites. Development of standard methodologies that generate Ts products routinely would be of broad benefit to the application of remote sensing data in areas such as hydrology and urban monitoring. AVHRR and MODIS datasets are routinely used to deliver Ts products. However, these data have 1km spatial resolution, which is too coarse to detect the detailed variation of land surface change of concern in many applications, especially in heterogeneous areas. Higher resolution thermal data from Landsat is a possible option in such cases. To derive Ts, two scientific problems need to be resolved: to remove the atmospheric effects and derive surface brightness temperature (TB) and to separate the emissivity and Ts effects in the surface brightness temperature (TB). To derive TB, for single thermal band sensors such as, Landsat 5, 7 and (due to a faulty dual-band thermal instrument) on Landsat-8, the split window methods, such as those used for NOAAAVHRR data (Becker & Li, 1990), and the day/night pairs of thermal infrared data in several bands, as used for MODIS (Wan et al., 2002) are not available for correcting atmospheric effects. The retrieval of surface brightness temperature TB from Landsat data therefore needs more care, as the accuracy of the TB retrieval depends critically on the ancillary data, such as atmospheric water vapour data (precipitable water). In this paper, a feasible operational method to remove the atmospheric effects and retrieve surface brightness temperature from Landsat data is presented. The method uses the MODTRAN 5 radiative transfer model and global atmospheric profile data sets, such as NASA MERRA (The Modern Era Retrospective-Analysis for Research and Applications) atmospheric profiles, NOAA NCEP (National Center for Environmental Prediction) reanalysis product and ECMWF (The European Centre for Medium-Range Weather Forecasts) to correct for the atmospheric effects. The results derived from the global atmospheric profiles are assessed against the TB product estimated by using (accurate) ground based radiosonde data (balloon data). The results from this study have found: The global data sets NCEP1, NCEP2, MERRA and ECMWF can all generally give satisfactory TB products and can meet the levels of accuracy demanded by many practitioners, such as 1º K. Among global data sets, ECMWF data set performs best. The root mean square difference (RMSD) for the 9 days and 3 test sites are all within 0.4º K when compared with the TB products estimated using ground radiosonde measurements.

  • We have developed a Building Fire Impact Model to evaluate the probability that a building located in a peri-urban region of a community is affected/destroyed by a forest fire. The methodology is based on a well-known mathematical technique called Event Tree (ET) modeling, which is a useful graphical way of representing the dependency of events. The tree nodes are the event itself, and the branches are formed with the probability of the event happening. If the event can be represented by a discrete random variable, the number of possible realisations of the event and their corresponding probability of occurring, conditional on the realisations of the previous event, is given by the branches. As the probability of each event is displayed conditional on the occurrence of events that precede it in the tree, the joint probability of the simultaneous occurrence of events that constitute a path is found by multiplication (Hasofer et al., 2007). BFIM contains a basic implementation of the main elements of bushfire characteristics, house vulnerability and human intervention. In the first pass of the BFIM model, the characteristics of the bushfire in the neighboring region to the house is considered as well as the characteristics of the house and the occupants of the house. In the second pass, the number of embers impacting on the house is adjusted for human intervention and wind damage. In the third pass, the model examines house by house conditions to determine what houses have been burnt and their impact on neighboring houses. To illustrate the model application, a community involved in the 2009 Victorian bushfires has been studied and the event post-disaster impact assessment is utilized to validate the model outcomes. MODSIM 2013 Conference

  • Wind multipliers are factors that transform regional wind speeds into local wind speeds, accounting for the local effects which include topographical, terrain and shielding influences. Wind multipliers have been successfully utilized in various wind related activities such as wind hazard assessment (engineering building code applications), event-based wind impact assessments (tropical cyclones), and also national scale wind risk assessment. The work of McArthur in developing the Forest Fire Danger Index (FFDI: Luke and McArthur, 1978) indicates that the contribution of wind speed to the FFDI is about 45% of the magnitude, indicating the importance of determining an accurate local wind speed in bushfire hazard and spread calculations. For bushfire spread modeling, local site variation (@ 100 metre and also 25 metre horizontal resolution) have been considered through the use of wind multipliers, and this has resulted in a significant difference to the currently utilized regional '10 metre height' wind speed (and further to the impact analysis). A series of wind multipliers have been developed for three historic bushfire case study areas; the 2009 Victorian fires (Kilmore fire), the 2005 Wangary fire (Eyre Peninsula), and the 2001 Warragamba - Mt. Hall fire (Western Sydney). This paper describes the development of wind multiplier computation methodology and the application of wind multipliers to bushfire hazard and impact analysis. The efficacy of using wind multipliers within a bushfire spread hazard model is evaluated by considering case study comparisons of fire extent, shape and impact against post-disaster impact assessments. The analysis has determined that it is important to consider wind multipliers for local wind speed determination in order to achieve reliable fire spread and impact results. From AMSA 2013 conference

  • A collection of mining and explotation tenements supplied by the individual state and territory bodies. Loaded monthly to an Oracle database from shapefiles given to Geoscience Australia.

  • To date, a range of methods have been developed and applied to the processing and analysis of underwater video and imagery, in part driven by different requirements. For example, in Australia, the marine science community who are partnered by the National Environmental Research Program (NERP) and funded by the Marine Biodiversity Hub, has developed a national CATAMI (Collaborative and Automated Tools for Analysis of Marine Imagery and video) scheme. Technological advances in recent years have improved the usability and output quality of underwater video and still images used to identify and monitor underwater habitats and structures and as a result, these techniques are more frequently applied to marine studies. So far, a comprehensive review of underwater video and still imagery processing/analysis methods has not been completed, although the number of studies utilising underwater stills and video has increased dramatically. Difficulties in diver limitation and stringent regulations applied to the collection of diver-based imagery and video data from underwater benthic habitats. Therefore, remote sensing methods such as underwater video and still imagery are becoming increasingly pivotal for ground-truthing benthic biological and physical habitats in shallow and deep marine and freshwater habitats and are also providing a permanent archive for future analyses. This review focuses on post-processing observational methods used for underwater video and still image habitat classification and quantification. We summarise the main applications, advantages and disadvantages of video and still imagery scoring methods, and illustrate recent advances in this topic.

  • Sediment grainsize and compositional data is presented for the East Antarctic region (30-150ºE) south of 60ºS to provide insight into the nature of habitats available for benthic communities. This compilation of sedimentary properties incorporates data collected and analysed from the 1950s to 2012. Sediment grainsize data is presented from quantitative analyses (472 samples) and Folk classifications (an additional 192 samples), and composition data is presented for calcium carbonate (255 samples) and biogenic silica (304 samples). Sedimentary properties are a key environmental layer for understanding the nature and diversity of benthic habitats. In this report, sediment grainsize and composition data are overlain on maps of bathymetry and geomorphic features, to further illustrate key variations in seabed habitats. The Antarctic shelf is typically dissected by deep troughs and channels, and these form sediment depocenters for fine grained biosiliceous material. Shelf banks, by contrast, are typically composed of coarser sands and gravels due to their exposure to stronger currents and frequent iceberg scouring. The continental slope is heavily eroded into rugged canyons which also contain coarser sediments due to reworking by down slope processes. In several regions, high carbonate content occurs at the shelf break, associated with areas of known hydrocoral occurrence. These variations in physical properties across the Antarctic shelf and slope create distinct habitats for seabed communities. Maps of sediment type, together with broader-scale maps of geomorphic features, can therefore guide understanding of the nature and distribution of seabed habitats in East Antarctica, and particularly within the seven proposed Marine Protected Areas (MPAs) within this region. Sedimentary and geomorphic properties are shown to be highly variable within these MPAs, indicating that these areas likely support a wide variety of benthic communities.

  • Geoscience Australia has completed a re-development of Sentinel, from the infrastructure that supports the system through to the spatial technology and user-interface. These changes will allow Geoscience Australia to more easily integrate data from different platforms and sources as well as provide additional products through the Sentinel interface. The new Sentinel system was developed in consultation with stakeholders to ensure a close alignment between end-users needs and the services provided by Sentinel. This paper presents the key features of the new Sentinel.

  • Geoscience Australia Flyer prepared for LOCATE14.

  • Data package containing an ESRI shapefile and associated comma-separated value table (.csv) of the Pacific islands, including the countries of Cook Islands, Federated States of Micronesia, Fiji, Kiribati, Nauru, Niue, Palau, Papua New Guinea, Republic of Marshall Islands, Samoa, Solomon Islands, Tokelau, Tonga, Tuvalu and Vanuatu. The ESRI shapefile contains polygons of the islands and has been adapted from the World Vector Shoreline dataset, with original scale suitability of 1:250,000 (reference: Soluri, E.A. and Woodson, V.A. 1990. World Vector Shoreline. International Hydrographic Review LXVII(1)). See lineage for more information. The .csv file contains tabular data associated with the island polygons. The file has been adapted to suit the purposes of the companion report by Dixon-Jain et al. (2014). The island polygon shapefile and .csv file can be joined using the common UniqueID field. The attribute fields within the .csv file include island hydrogeological and physical characteristics. Relative ratings for component of the potential vulnerability framework are included for the two projection periods (2035-2064 and 2070-2099), for each climate hazard (low rainfall periods and mean sea-level rise). See the field list within lineage in the Data Dictionary for more information on the source of each attribute. The full bibliographic reference for the companion report (catalogue number 79066) is: Dixon-Jain, P., Norman, R., Stewart, G., Fontaine, K., Walker, K., Sundaram, B., Flannery, E., Riddell, A., Wallace, L. 2014. Pacific Island Groundwater and Future Climates: First-Pass Regional Vulnerability Assessment. Record 2014/43. Geoscience Australia, Canberra. http://dx.doi.org/10.11636/Record.2014.043