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  • This report describes the results of an extended national field spectroscopy campaign designed to validate the Landsat 8 and Sentinel 2 Analysis Ready Data (ARD) surface reflectance (SR) products generated by Digital Earth Australia. Field spectral data from 55 overpass coincident field campaigns have been processed to match the ARD surface reflectances. The results suggest the Landsat 8 SR is validated to within 10%, the Sentinel 2A SR is validated to within 6.5% and Sentinel 2B is validated to within 6.8% . Overall combined Sentinel 2A and 2B are validated within 6.6% and the SR for all three ARD products are validated to within 7.7%.

  • Plutonium (Pu) interactions in the environment are highly complex. Site-specific variables play an integral role in determining the chemical and physical form of Pu, and its migration, bioavailability, and immobility. This paper aims to identify the key variables that can be used to highlight regions of radioecological sensitivity and guide remediation strategies in Australia. Plutonium is present in the Australian environment as a result of global fallout and the British nuclear testing program of 1952 – 1958 in central and west Australia (Maralinga and Monte Bello islands). We report the first systematic measurements of 239+240Pu and 238Pu activity concentrations in distal (≥1,000 km from test sites) catchment outlet sediments from Queensland, Australia. The average 239+240Pu activity concentration was 0.29 mBq.g -1 (n = 73 samples) with a maximum of 4.88 mBq.g -1. 238Pu/239+240Pu isotope ratios identified a large range (0.02 – 0.29 (RSD: 74%)) which is congruent with the heterogeneous nuclear material used for the British nuclear testing programme at Maralinga and Montebello Islands. The use of a modified PCA relying on non-linear distance correlation (dCorr) provided broader insight into the impact of environmental variables on the transport and migration of Pu in this soil system. Primary key environmental indicators of Pu presence were determined to be actinide/lanthanide/heavier transition metals, elevation, electrical conductivity (EC), CaO, SiO2, SO3, landform, geomorphology, land use, and climate explaining 81.7% of the variance of the system. Overall this highlighted that trace level Pu accumulations are associated with the coarse, refractive components of Australian soils, and are more likely regulated by the climate of the region and overall soil type. <b>Citation:</b> Megan Cook, Patrice de Caritat, Ross Kleinschmidt, Joёl Brugger, Vanessa NL. Wong, Future migration: Key environmental indicators of Pu accumulation in terrestrial sediments of Queensland, Australia,<i> Journal of Environmental Radioactivity</i>, Volumes 223–224, 2020, 106398,ISSN 0265-931X, https://doi.org/10.1016/j.jenvrad.2020.106398

  • This Gunnedah Basin dataset contains descriptive attribute information for the areas bounded by the relevant spatial groundwater feature in the associated Hydrogeology Index map. Descriptive topics are grouped into the following themes: Location and administration; Demographics; Physical geography; Surface water; Geology; Hydrogeology; Groundwater; Groundwater management and use; Environment; Land use and industry types; and Scientific stimulus. The Gunnedah Basin is an intracratonic, sedimentary basin in northern NSW. It forms the middle section of the greater Sydney-Gunnedah-Bowen Basin system and mainly consists of Permian and Triassic sedimentary rocks resting on Late Carboniferous to Early Permian volcanics. The Gunnedah Basin is overlain by the Surat Basin and the younger alluvial sediments associated with modern and ancient river systems. The Gunnedah Basin is not considered a single well-connected aquifer, rather a series of porous rock aquifers separated by several non-porous or poorly conductive layers. The Lachlan Fold Belt forms what is thought to be an effective basement although little information is known of its hydrogeological properties. All units of the Gunnedah Basin are of low permeability and significantly lower hydraulic conductivity than the overlying alluvial aquifers. Most of the groundwater resources in the area are extracted from either the overlying Surat Basin or younger alluvial aquifers. There is relatively little groundwater sourced from the aquifers of the Gunnedah Basin, except in areas where the overlying aquifers do not occur. The most viable groundwater source in the Gunnedah Basin are the more porous aquifers of the Triassic sequence.

  • This Wiso Basin dataset contains descriptive attribute information for the areas bounded by the relevant spatial groundwater feature in the associated Hydrogeology Index map. Descriptive topics are grouped into the following themes: Location and administration; Demographics; Physical geography; Surface water; Geology; Hydrogeology; Groundwater; Groundwater management and use; Environment; Land use and industry types; and Scientific stimulus. The Wiso Basin, a large intra-cratonic basin in the central Northern Territory, covers about 140,000 square kilometres and is part of the Centralian Superbasin. It is bounded by the Tennant and Tanami regions to the east and west, while a thrust fault separates it from the Arunta Region to the south. The basin adjoins the Georgina Basin in the southeast and joins the Daly and Georgina basins beneath the Cretaceous strata of the Carpentaria Basin in the north. The basin contains a relatively flat, undeformed succession of strata that gently dip towards the main depo-centre, the Lander Trough. About 80% of the basin consists of shallow middle Cambrian strata, while the remaining portion is within the Lander Trough, containing a diverse succession of Cambrian, Ordovician, and Devonian units. The depositional history and stratigraphy reveal that early Cambrian saw widespread basaltic volcanism, with the Antrim Plateau Volcanics forming the base layer and aquitard of the Wiso Basin. The middle Cambrian deposits include the Montejinni Limestone, the oldest sedimentary unit, followed by the Hooker Creek Formation and the Lothari Hills Sandstone. The uppermost Cambrian unit is the Point Wakefield beds. The Ordovician deposits consist of the Hansen River beds, primarily composed of fossiliferous sandstone and siltstone deposited in shallow marine environments. The Devonian unit capping the basin is the Lake Surprise Sandstone, found in the Lander Trough area, formed in shallow marine, shoreline, and fluvial environments during the Alice Springs Orogeny. Three main hypotheses have been proposed for the formation of the Lander Trough: a large crustal downwarp before thrusting of Paleoproterozoic rocks, the formation of a half-graben by faulting along the southern boundary, or the formation of two en-echelon synclines by vertical block movement. While the majority of the Wiso Basin consists of shallow middle Cambrian rocks, the Lander Trough presents a more varied stratigraphic sequence, holding potential for Neoproterozoic and early Cambrian rocks. However, further drilling is needed to verify this. The presence of similar units in neighbouring basins provides valuable insight into the basin's geological history and development.

  • Wetlands around the world provide crucial ecosystem services and are under increasing pressure from multiple sources including climate change, changing flow and flooding regimes, and encroaching human populations. The Landsat satellite imagery archive provides a unique observational record of how wetlands have responded to these impacts during the last three decades. Information stored within this archive has historically been difficult to access due to its petabyte-scale and the challenges in converting Earth observation data into biophysical measurements that can be interpreted by wetland ecologists and catchment managers. This paper introduces the Wetlands Insight Tool (WIT), a workflow that generates WIT plots that present a multidecadal view of the biophysical cover types contained within individual Australian wetlands. The WIT workflow summarises Earth observation data over 35 years at 30 m resolution within a user-defined wetland boundary to produce a time-series plot (WIT plot) of the percentage of the wetland covered by open water, areas of water mixed with vegetation (‘wet’), green vegetation, dry vegetation, and bare soil. We compare these WIT plots with documented changes that have occurred in floodplain shrublands, alpine peat wetlands, and lacustrine and palustrine wetlands, demonstrating the power of satellite observations to supplement ground-based data collection in a diverse range of wetland types. The use of WIT plots to observe and manage wetlands enables improved evidence-based decision making. <b>Citation:</b> Dunn, B., Ai, E., Alger, M.J. et al. Wetlands Insight Tool: Characterising the Surface Water and Vegetation Cover Dynamics of Individual Wetlands Using Multidecadal Landsat Satellite Data. <i>Wetlands</i><b> 43</b>, 37 (2023). https://doi.org/10.1007/s13157-023-01682-7

  • The National Geochemical Survey of Australia (NGSA) is Australia’s first national-scale geochemical survey. It was delivered to the public on 30 June 2011, after almost five years of stakeholder engagement, strategic planning, sample collection, preparation and analysis, quality assurance/quality control, and preliminary data analytics. The project was comprehensively documented in seven initial open-file reports and six data and map sets, followed over the next decade by more than 70 well-cited scientific publications. This review compiles the body of work and knowledge that emanated from the project to-date as an indication of the impact the NGSA had over the decade 2011-2021. The geochemical fabric of Australia as never seen before has been revealed by the NGSA. This has spurred further research and stimulated the mineral exploration industry. This paper also critically looks at operational decisions taken at project time (2007-2011) that were good and perhaps – with the benefit of hindsight – not so good, with the intention of providing experiential advice for any future large-scale geochemical survey of Australia or elsewhere. Strengths of the NGSA included stakeholder engagement, holistic approach to a national survey, involvement of other geoscience agencies, collaboration on quality assurance with international partners, and targeted promotion of results. Weaknesses included gaining successful access to all parts of the nation, and management of sample processing in laboratories. <b>Citation:</b> Patrice de Caritat; The National Geochemical Survey of Australia: review and impact. <i>Geochemistry: Exploration, Environment, Analysis </i>2022;; 22 (4): geochem2022–032. doi: https://doi.org/10.1144/geochem2022-032 This article appears in multiple journals (Lyell Collection & GeoScienceWorld)

  • The Great Artesian Basin (GAB) covers one fifth of Australia and is the largest groundwater ‘basin’ on the continent. Groundwater from the GAB is a vital resource for pastoral, agricultural and extractive industries, underpinning at least $12.8 billion in economic activity annually, as well as providing town water supplies and supporting environmental and cultural values. The Australian Government, through the National Water Infrastructure Development Fund – Expansion, commissioned Geoscience Australia to undertake the project ‘Assessing the Status of Groundwater in the Great Artesian Basin’. A key deliverable of this project is a water balance (for 2019) encompassing the main aquifers of the GAB. To facilitate this outcome, a range of tools and techniques to assist in the development of improved hydrogeological conceptualisations of the GAB have been developed and assessed. This report presents the results of investigations from a pilot study area in the northern Surat Basin, Queensland, with components of the work extending into the wider GAB. The results demonstrate that the application of existing and new geoscientific data and technologies has the potential to further improve our understanding of the GAB hydrogeological system thus supporting the responsible management of basin water resources. Groundwater recharge potential within the GAB intake beds has been investigated using techniques that consider variations in physical and environmental characteristics. Empirical modelling assessing deep drainage as a recharge proxy suggests that, with isolated exceptions, diffuse recharge potential is generally low across most of the study area. The spatial variability in recharge potential can assist in the interpretation and/or interpolation of estimates derived from other techniques, such as chloride mass balance. The results of machine learning modelling suggest that further work is needed to better constrain uncertainty in input and training datasets, and in the development of robust translations of outputs to hydrogeologically meaningful products. The chloride mass balance (CMB) method remains the most appropriate tool for estimating long-term mean gross recharge to GAB aquifers in the northern Surat Basin. New upscaling methods provide significant improvements for mapping regional scale groundwater recharge rates and quantifying uncertainties associated with these estimates. Application of multiple techniques to the assessment of groundwater flow and recharge processes is necessary to complement CMB recharge estimates, and reduce associated uncertainty. Analysis of groundwater environmental tracers are recommended for constraining CMB recharge rates. Integrated geological assessments using airborne electromagnetic data in conjunction with other geophysical and geological data (e.g., reflection seismic, wells) are effective at characterising aquifer architecture to better understand geometry, flow pathways and structural controls relevant to recharge and connectivity at local to regional scales. Significant effort has gone into updating the regional geological framework at the whole-of-GAB scale, combining legacy and new data with recent knowledge to revise the hydrogeological conceptualisation of the GAB. This assists in constraining interpretations of regional depositional architecture and lithological heterogeneity within hydrogeological units, particularly those properties that influence groundwater storage and flux. Assessment of lateral and vertical heterogeneity of hydraulic properties within and between aquifers and aquitards in the northern Surat Basin has refined our understanding of potential groundwater connectivity and compartmentalisation. This study provides an improved hydrogeological framework to support revised water balance estimates for the GAB, and insights into potential recharge variability that may impact those input components. Targeted examples from the northern Surat Basin demonstrate the application of the techniques and tools employed, including methods to reduce uncertainty. The outcomes of this work underpin a revised hydrogeological conceptualisation for the GAB, a standardised basis for establishing future investigations, and a framework for more informed water management decision-making.

  • This animation shows how groundwater sampling is conducted. It is part of a series of Field Activity Technique Engagement Animations. The target audience are the communities that are impacted by GA's data acquisition activities. There is no sound or voice over. The 2D animation includes a simplified view of what groundwater sampling equipment looks like, what the equipment measures and how scientists use the data.

  • Background It is important to know where water is normally present in a landscape, where water is rarely observed, and where inundation has occasionally occurred. These observations tell us where flooding has occurred in the past, and allows us to understand wetlands, water connectivity and surface-groundwater relationships. This can lead to more effective emergency management and risk assessment. This is the principal Digital Earth Australia (DEA) Water product (previously known as Water Observations from Space (WOfS)), providing the individual water observations per satellite image that are subsequently used in the following DEA Watersuite and related water bodies products: DEA Waterbodies (Landsat), DEA Water Observations Statistics (Landsat), DEA Water Observations Filtered Statistics (Landsat). This product shows where surface water was observed by the Landsat satellites on any particular day since mid 1986. These daily data layers are termed Water Observations (WOs). What this product offers DEA Water Observations provides surface water observations derived from Landsat satellite imagery for all of Australia from 1986 to present. The Water Observationsshow the extent of water in a corresponding Landsat scene, along with the degree to which the scene was obscured by clouds, shadows or where sensor problems cause parts of a scene to not be observable.

  • This animation shows how borehole geophysical surveys are conducted. It is part of a series of Field Activity Technique Engagement Animations. The target audience are the communities that are impacted by GA's data acquisition activities. There is no sound or voice over. The 2D animation includes a simplified view of what borehole geophysics equipment looks like, what the equipment measures and how scientists use the data.