<div>The Australian Government's Trusted Environmental and Geological Information program is a collaboration between Geoscience Australia and CSIRO. Part of this program includes baseline geological and environmental assessments. </div><div> Hydrogeological information has been collated for the Adavale, Cooper, Galilee and north Bowen basins and overlying basins, including the Eromanga and Lake Eyre basins. This information will provide a regionally-consistent baseline dataset that will be used to develop groundwater conceptualisation models.</div><div> Publicly-available data within these basin regions have been compiled from over 30&nbsp;000 boreholes, 120 stream gauges, and 1100 rainfall stations, resulting in revised hydrostratigraphic frameworks. From the published literature, 14 major hydrostratigraphic units are recognised within the basin regions. For each of these major hydrostratigraphic units, we determined the salinity, Darcian yield, specific yield/storativity, groundwater reserve volume for unallocated groundwater, groundwater levels/hydrological pressure, likelihood of inter-aquifer connectivity, rainfall, connectivity between surface water and groundwater, and water-use volume statistics, where relevant, for each basin, hydrogeological province and aquifer. We then adopted a play-based approach to develop holistic hydrostratigraphic conceptualisations of the basin regions. </div><div> Within the Adavale Basin we have defined a new hydrogeological province including two new aquifers defined as the moderate salinity and moderately overpressured Buckabie-Etonvale Aquifer, and the hypersaline and hyper-overpressured Lissoy-Log Creek-Eastwood Aquifer. Similarities between the upper Buckabie-Etonvale Aquifer of the Adavale Basin and lowermost Joe Joe Group of the Galilee Basin suggests connectivity between the upper Adavale and lower Galilee basins. Hydraulic pressures (up to 1500 m of excess freshwater head) calculated for the Lissoy–Log Creek–Eastwood Aquifer indicate that if the aquifer was to be breached, there is potential localised risk to overlying aquifers and surface environments, including infrastructure.</div><div><br></div><div><strong>Author Biography:</strong></div><div>Dr. Chris Gouramanis is a hydrogeologist working in the Trusted Environmental and Geological Information program, in the Minerals, Energy and Groundwater Division of Geoscience Australia. Chris was awarded his PhD from The Australian National University in 2009 and has held several water and environmental policy positions within the Australian Government. He worked for 10 years as an academic at the Earth Observatory of Singapore and the Geography Department at the National University of Singapore. He is also Australia’s National Focal Point to the Scientific and Technical Review Panel of the Ramsar Convention on Wetlands.</div><div><br></div>This Abstract was submitted/presented to the 2022 Australasian Groundwater Conference 21-23 November (https://agc2022.com.au/)

<div>This is a conference abstract discussing the compilation of information for our consistent national understanding across the major hydrogeological regions of Australia. This work is a component of the National Groundwater Systems project within the Exploring for the Future program.</div>

<div>This report presents the findings of a study conducted in the upper Darling River floodplain, aimed at improving optical and interferometric synthetic aperture radar (InSAR) remote sensing products for groundwater dependant vegetation (GDV) characterisation. The research was part of the Upper Darling Floodplain (UDF) groundwater study, funded by the Exploring for the Future program.</div><div>This work tests the suitability of two novel remote sensing methods for characterising ecosystems with a range of likely groundwater dependence: combined wetness and greenness indices derived from Landsat products available through Geoscience Australia’s Digital Earth Australia platform, and an InSAR derived index of vegetation structure (known as SARGDE), which has been so far tested only in northern Australia. In addition, the relationship between the Normalised Difference Vegetation Index (NDVI), a remotely sensed proxy for vegetation condition, and water availability from surface water flows, rainfall, and groundwater was tested for sites with a range of low to high likely groundwater dependence.&nbsp;</div><div>The key findings of this work, and potential implications, are:</div><div>• A multiple lines of evidence approach, drawing on persistence of wetness/greenness and vegetation structure, and correlation between inferred vegetation condition and groundwater levels, gives high confidence in the groundwater dependence of parts of the floodplain, particularly within the riparian zone. These indices require calibration with ground condition data to be applied in different regions, but a combined index could provide a high confidence measure of groundwater dependence.</div><div>• Combined greenness and wetness, SARGDE, and the relationship between NDVI and groundwater levels all showed areas classified as ‘moderate’ likelihood of groundwater dependence having signatures comparable to areas classified as high likelihood. This could address a shortcoming of the groundwater dependence classification methodology, which, when groundwater level information is missing, classifies some vegetation types as moderate.</div><div>• A combined index taking into account both greenness and wetness was able to better delineate vegetation types with a range of groundwater dependence previously not achievable using remote sensing products.&nbsp;</div><div>This work has provided improved methodology for applying remote sensing products to groundwater dependent vegetation characterisation in the study area. The methods are likely to be applicable to other regions with groundwater dependent vegetation. The results add to the evidence that it is necessary to better integrate surface and groundwater resources in water sharing plans at a basin scale. Further work is required to quantify the frequency and magnitude of flow events required to replenish alluvial groundwater sufficiently to maintain existing groundwater dependent ecosystems.&nbsp;&nbsp;</div><div><br></div><div><br></div>

<div>The Exploring for the Future program is a world leading program, delivering public geoscientific data and information required to empower decision-makers and attract future investment in resource exploration and development. Geoscience Australia engaged Alluvium Consulting Australia to quantify the impact and value of groundwater activities and outputs to the quadruple bottom line through an evaluation of 2 case studies, namely: • National Hydrogeological Mapping • The Southern Stuart Corridor project. This involved understanding the impact pathways for these case studies and the collection of data to be used in a cost benefit analysis. The work sought to provide feedback to Geoscience Australia, stakeholder groups and the broader community on the value of Geoscience Australia’s groundwater activities. The case study evaluations were facilitated by a series of specific questions, which were developed to guide data collection and the building of a knowledge base around the impact and value of the work in each case study and associated outputs. The questions broadly fell under the following categories: 1. Uptake and Usage 2. Impact 3. Benefit These evaluations were framed around the program impact pathway developed for each case study. This is a description of how inputs are used to deliver activities, which in turn result in outcomes and impacts (changes) for stakeholders, including the environment. The primary means of data collection to help answer the key evaluation questions was through online workshops and interviews with key stakeholders for each case study. These were undertaken between March 10 and March 24, 2023. In these workshops and interviews, representatives from industry, community and government agencies were asked if they could identify instances where case study program outputs were used for particular purposes, such as prioritising research or investment, advising Members of Parliament, or education and training. These examples were then explored further to understand what outcomes and benefits were derived from the use of the case study outputs, and how critical were the case study outputs to achieving those outcomes and benefits</div>

This was the third of five presentations held on 31 July 2023 as part of the National Groundwater Systems Workshop - WaMSTeC: Water Monitoring and Standardisation Technical Committee National Industry Guidelines for hydrometric monitoring WaMSTeC GUIDELINE REVISIONS UPDATE FOR GROUNDWATER COMPONENTS: GROUNDWATER SUBCOMMITTEE

This was the first of five presentations held on 31 July 2023 as part of the National Groundwater Systems Workshop - A clear and consistent inventory of knowledge about Australia’s major hydrogeological provinces.

<div>The Lake Eyre surface water catchment covers around 1,200,000 km2 of central Australia, about one-sixth of the entire continent. It is one of the largest endorheic river basins in the world and contains iconic arid streams such as the Diamantina, Finke and Georgina rivers, and Cooper Creek. The Lake Eyre region supports diverse native fauna and flora, including nationally significant groundwater-dependent ecosystems such as springs and wetlands which are important cultural sites for Aboriginal Australians.</div><div><br></div><div>Much of the Lake Eyre catchment is underlain by the geological Lake Eyre Basin (LEB). The LEB includes major sedimentary depocentres such as the Tirari and Callabonna sub-basins which have been active sites of deposition throughout the Cenozoic. The stratigraphy of the LEB is dominated by the Eyre, Namba and Etadunna formations, as well as overlying Pliocene to Quaternary sediments.</div><div><br></div><div>The National Groundwater Systems Project, part of Geoscience Australia's Exploring for the Future Program (https://www.eftf.ga.gov.au/), is transforming our understanding of the nation's major aquifer systems. With an initial focus on the Lake Eyre Basin, we have applied an integrated geoscience systems approach to model the basin's regional stratigraphy and geological architecture. This analysis has significantly improved understanding of the extent and thickness of the main stratigraphic units, leading to new insights into the conceptualisation of aquifer systems in the LEB.</div><div><br></div><div>Developing the new understanding of the LEB involved compilation and standardisation of data acquired from thousands of petroleum, minerals and groundwater bores. This enabled consistent stratigraphic analysis of the major geological surfaces across all state and territory boundaries. In places, the new borehole dataset was integrated with biostratigraphic and petrophysical data, as well as airborne electromagnetic (AEM) data acquired through AusAEM (https://www.eftf.ga.gov.au/ausaem). The analysis and integration of diverse geoscience datasets helped to better constrain the key stratigraphic horizons and improved our overall confidence in the geological interpretations.</div><div><br></div><div>The new geological modelling of the LEB has highlighted the diverse sedimentary history of the basin and provided insights into the influence of geological structures on modern groundwater flow systems. Our work has refined the margins of the key depocentres of the Callabonna and Tirari sub-basins, and shown that their sediment sequences are up to 400 m thick. We have also revised maximum thickness estimates for the main units of the Eyre Formation (185 m), Namba Formation (265 m) and Etadunna Formation (180 m).</div><div><br></div><div>The geometry, distribution and thickness of sediments in the LEB is influenced by geological structures. Many structural features at or near surface are related to deeper structures that can be traced into the underlying Eromanga and Cooper basins. The occurrence of neotectonic features, coupled with insights from geomorphological studies, implies that structural deformation continues to influence the evolution of the basin. Structures also affect the hydrogeology of the LEB, particularly by compartmentalising groundwater flow systems in some areas. For example, the shallow groundwater system of the Cooper Creek floodplain is likely segregated from groundwater in the nearby Callabonna Sub-basin due to structural highs in the underlying Eromanga Basin.</div><div> Abstract submitted and presented at the 2023 Australian Earth Science Convention (AESC), Perth WA (https://2023.aegc.com.au/)

<div>Geoscience Australia's Exploring for the Future Program (EFTF) is supporting regional and national-scale initiatives to address Australia’s hydrogeological challenges using an integrated geoscience systems approach. An important early step in the EFTF groundwater program focused on developing a national hydrogeological inventory of Australia’s major groundwater basins and fractured rock provinces. The inventory has its roots in the seminal 1987 Hydrogeology of Australia map, the first continental-scale map of groundwater systems and principal aquifers (Jacobson and Lau, 1987). Seeking to enhance and modernise the supporting information base for the national map, the inventory combines a curated selection of geospatial data attributes supported by focused narrative on the geology and hydrogeology of each basin and fractured rock province.</div><div>&nbsp;</div><div>The national hydrogeological inventory has a broad range of benefits for Australian groundwater users, managers and policy makers. These include the provision of an updated knowledge base covering the hydrogeology and groundwater systems of the major hydrogeological provinces of the nation, as well as important contextual information. The extensive catalogue of knowledge contained in the inventory also enables an objective approach to identify and prioritise areas for further regional assessment.</div><div>&nbsp;</div><div>Based on analysis of data compiled for the national inventory, the Lake Eyre Basin in arid central Australia was the first region prioritised for more detailed hydrogeological assessment during EFTF. The integration of a variety of basin- to national-scale geoscience datasets enabled significant advances in geological and hydrogeological understanding and the development of a new geological model for the three main basin depo-centres, namely the Tirari and Callabonna Sub-basins, and the Cooper Creek Palaeovalley. The geological modelling has further supported a range of hydrogeological applications, including substantial improvements in the number of bores with aquifer attribution, as well as the first regional watertable map across the basin. Abstract submitted and presented at the 2023 AGC NZHS Joint Conference Auckland, NZ (https://www.agcnzhs2023conference.co.nz/)

<div>Groundwater dependent ecosystems (GDEs) rely on access to groundwater on a permanent or intermittent basis to meet some or all of their water requirements (Richardson et al., 2011). The <a href="https://explorer-aws.dea.ga.gov.au/products/ga_ls_tc_pc_cyear_3">Tasselled Cap percentile products</a> created by Digital Earth Australia (2023) were used to identify potential GDEs for the upper Darling River floodplain study area. These percentile products provide statistical summaries (10th, 50th, 90th percentiles) of landscape brightness, greenness and wetness in imagery acquired between 1987 and present day. The 10th percentile greenness and wetness represent the lowest 10% of values for the time period evaluated, e.g. 10th greenness represents the least green period. In arid regions, areas that are depicted as persistently green and/or wet at the 10th percentile have the greatest potential to be GDEs. For this reason, and due to accessibility of the data, the 10th percentile Tasselled Cap greenness (TCG) and Tasselled Cap wetness (TCW) products were used as the basis for the assessment of GDEs for the upper Darling River floodplain study area. </div><div><br></div><div>This data release is an ESRI geodatabase, with layer files, including:</div><div><br></div><div>-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;original greenness and wetness datasets extracted; </div><div><br></div><div>-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;classified 10th percentile greenness and wetness datasets (used as input for the combined dataset); </div><div><br></div><div>-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;combined scaled 10th percentile greenness and wetness dataset (useful for a quick glance to identify potential groundwater dependent vegetation (GDV) that have high greenness and wetness e.g. river red gums)</div><div><br></div><div>-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;combined classified 10th percentile greenness and wetness dataset (useful to identify potential GDV/GDE and differentiate between vegetation types)</div><div><br></div><div>-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;coefficient of variation of 50th percentile greenness dataset (useful when used in conjunction with the scaled/combined products to help identify GDEs)</div><div><br></div><div>For more information and detail on these products, refer to <a href="https://dx.doi.org/10.26186/148545">https://dx.doi.org/10.26186/148545</a>.</div><div><br></div><div><strong>References</strong></div><div>Digital Earth Australia (2023). <em><a href="https://docs.dea.ga.gov.au">Digital Earth Australia User Guide</a></em>. </div><div>Richardson, S., E. Irvine, R. Froend, P. Boon, S. Barber, and B. Bonneville. 2011a. <em>Australian groundwater-dependent ecosystem toolbox part 1: Assessment framework.</em> Waterlines Report 69. Canberra, Australia: Waterlines.</div>

<div>Australia is the driest inhabited continent on Earth and groundwater is crucial to maintaining the country’s population, economic activities, Indigenous culture and environmental values. Geoscience Australia is renewing a national-scale focus to tackle hydrogeological challenges by building upon our historic legacy in groundwater studies at regional and national scales.</div><div><br></div><div>The most comprehensive hydrogeological coverage of the nation is the 1987 Hydrogeology of Australia map, developed by a predecessor of Geoscience Australia. This map provides an overview of groundwater systems and principal aquifers across Australia, based upon the large sedimentary basins, intervening fractured rock areas and smaller overlying sedimentary/volcanic aquifers. However, the currency and completeness of the information presented and accompanying the national hydrogeology map needs to be improved. Updating the extents, data and scientific understanding of the hydrogeological regions across Australia, and improving the accessibility and useability of this information will address many of its current limitations.</div><div><br></div><div>Geoscience Australia, within its Exploring for the Future program, is compiling hydrogeological and related contextual information clearly and consistently across Australia’s major sedimentary basins and intervening fractured rock provinces. This information has been collected for 41 major hydrogeological regions spanning the continent: 36 sedimentary basins and 5 regions dominated by fractured-rock aquifers. The information, collected through a combination of geospatial analyses of national datasets and high-level summaries of scientific literature, will be presented through Geoscience Australia’s online data discovery portal, thereby enabling improved interrogation and integration with other web mapping services.</div><div><br></div><div>The new compilation of nationally consistent groundwater data and information will help to prioritise future investment for new groundwater research in specific regions or basins, inform the work programs of Geoscience Australia and influence the prioritisation of national hydrogeological research more broadly.&nbsp;</div><div><br></div>This Abstract was submitted/presented to the 2022 Australasian Groundwater Conference 21-23 November (https://agc2022.com.au/)