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  • Geoscience Australia has developed a wind hazard model for estimating the risk posed by peak wind gusts. In this study we have utilised the regional return period wind gusts as defined in the Australian/New Zealand wind loading standard (AS/NZS 1170.2, 2002) and applied the methodology detailed in the standard. In addition, our association with Dr. John Holmes (chairperson of the Australian Wind Loading committee) allowed us to make a significant attempt to remove the conservatism associated with the wind loading standard. Geoscience Australia entered into discussions with Dr. Holmes which resulted in a consultancy that reviewed the Geoscience Australia wind risk methodology and vulnerability model development (Holmes, 2004). Geoscience Australia's basic approach is detailed in the Perth Cities report (Lin et al., 2005). In the present study we build on that earlier work by examining three other city regions and contrasting the results. Each component of the methodology is described in this section with a brief overview provided below: Estimated return period regional wind speeds (for peak 3 second gusts at a height of 10 metres in open level terrain) were obtained from AS/NZS 1170.2. The local wind effects on these return period regional wind speeds were determined by assessing the local effect of terrain at the structure height of interest, the shielding effect on the structure and the topographic effect. These effects were numerically estimated using remote sensing techniques, digital elevation data and by using formulae given in AS/NZS 1170.2. Finally, the estimation of the local wind speeds that would be equalled or exceeded within a given time period (commonly called return period wind speeds or return levels) was derived by combining the local wind multipliers (terrain/height, shielding and topographic) for 8 cardinal directions with the return period regional wind speeds (from AS/NZS 1170.2) across a 25 by 25 metre grid covering each study region.

  • These datasets cover approximately 30 sq km over the Mornington Island Community and are part of the 2006 North Queensland Communities LiDAR capture project. This project, undertaken by Fugro Spatial Solutions Pty Ltd on behalf of the Queensland Government captured highly accurate elevation data using LiDAR technology. Available dataset formats (in 1 kilometre tiles) are: - Classified las (LiDAR Data Exchange Format where strikes are classified as ground or non-ground) - Ground-classified LiDAR returns in XYZ format - non-ground classified LiDAR returns in XYZ format

  • Technical report on operational activities, including data, analysis and interpretation, for the Ti Tree demonstration study site conducted for the Palaeovalley Groundwater Project. This work was funded by the National Water Commission and managed by Geoscience Australia.

  • Map compiled on request from AGS Native Title Case QUD6040/2001 Proclamation 3 See 2008/3111 for particulars.

  • Diagram produced for inclusion in Limits of Continental Shelf Proclamation - Option 3 (In Confidence)

  • Continuity of Earth Observation Data for Australia - Operational Requirements to 2015 for Lands, Coasts and Oceans

  • A challenge for climate change researchers and planners alike is to understand the urban form in the future to assess needs and risks. Most impacts of climate change won't be clear until 2050 or later, however population projections, dwelling projections and development plans generally go no further than a 30 year time period. This leaves a gap in the understanding of the urban form between the end of the projections and future climate change impacts. Geoscience Australia in partnership with the Department of Climate Change and Energy Efficiency is developing a method that can model the urban form and adaptation scenarios. The method is based on existing models, but is generalised to enable linkage to the National Exposure Information System (NEXIS) and be implemented in a nationally consistent manner. The model is focussed on building vulnerability, namely building age, but implementing social vulnerability is also being considered.

  • A new approach for the 1D inversion of AEM data has been developed. We use a reversible jump Markov Chain Monte Carlo method to perform Bayesian inference. The Earth is partitioned by a variable number of non-overlapping cells defined by a 1D Voronoi tessellation. A cell is equivalent to a layer in conventional AEM inversion and has a corresponding conductivity value. The number and the position of the cells defining the geometry of the structure with depth, as well as their conductivities, are unknowns in the inversion. The inversion is carried out with a fully non-linear parameter search method based on a transdimensional Markov chain. Many conductivity models, with variable numbers of layers, are generated via the Markov chain and information is extracted from the ensemble as a whole. The variability of the individual models in the ensemble represents the posterior distribution. Spatially averaging results is a form of 'data-driven' smoothing, without the need to impose a specific number of layers, an explicit smoothing function, or choose regularization parameters. The ensemble can also be examined to ascertain the most probable depths of the layer interfaces in the vertical structure. The method is demonstrated with synthetic time-domain AEM data. The results show that an attractive feature of this method over conventional approaches is that rigorous information about the non-uniqueness and uncertainty of the solution is obtained. We also conclude that the method will also have utility for AEM system selection and investigation of calibration problems.

  • Developing Scientific Applications in Python

  • This metadata sheet refers to the following three shapefiles: flight_lines_ci11.shp photo_centres_ci11.shp photo_rectangles_ci2011.shp They can all be found in the following directory: \CIGIS\orthophoto\ortho2011 Together these datasets show the flight lines flown by AAM during the 2011 aerial survey of Christmas Island, the centre of each aerial photograph taken during flight and approximate photograph extent rectangles.