This project was conducted by Geoscience Australia in collaboration with the Water Science Branch of the Department of Water, Western Australia, to acquire baseline information supporting the condition assessment for Hardy Inlet. The project contributes to the Estuarine Resource Condition Indicators project funded by the Strategic Reserve of the National Action Plan for Salinity and Water Quality / National Heritage Trust and forms part of the Resource Condition Monitoring endorsed under the State (Western Australia) Natural Resource Management framework. Two surveys were undertaken in Hardy Inlet in September 2007 and April 2008 with the aim to develop an understanding of the historical environmental changes and current nutrient and sediment conditions for the purpose of developing sediment indicators to characterise estuary condition.

This report presents the results of a study by Geoscience Australia of Stokes Inlet and Wellstead Estuary, located in southwestern Western Australia, based on data collected during surveys in March 2006 and May 2007. It includes the present day rates of organic matter breakdown in the sediments of these estuaries, sediment and porewater properties, sedimentation rates, and an account of the historical environmental changes to these estuaries based on the sediment record. In the report you will find: 1. Purpose and background 2. Environmental Setting 3. Methods 4. Benthic Chambers 5. Sediment Cores and Grabs 6. Results and Discussions 7. Environmental conditions during the survey 8. Present-day nutrient dynamics in Stokes Inlet 9. Palaeoenvironmental reconstruction 10. Key conclusions

Islands in the Pacific region rely heavily on their fresh groundwater, and for a number of islands it is the only reliable source of freshwater throughout the year. Stresses on groundwater resources in many Pacific Island countries are set to escalate in the future with projected population and economic growth. In addition, there are likely to be future climate impacts on groundwater availability and quality. Although a number of studies have been undertaken at a local scale, very limited information is available to consider the impacts of future climates on groundwater systems at a regional scale. This project provides a first-pass regional-scale assessment of the relative potential vulnerability of groundwater to: (i) low rainfall periods and (ii) mean sea-level rise for 15 Pacific Island countries and territories. The dataset associated with this report can be obtained from www.ga.gov.au using title "Pacific Island Groundwater Vulnerability to Future Climates Dataset" or catalogue number 81575.

The Great Artesian Basin Research Priorities Workshop, organised by Geoscience Australia (GA), was held in Canberra on 27 and 28 April 2016. Workshop attendees represented a spectrum of stakeholders including government, policy, management, scientific and technical representatives interested in GAB-related water management. This workshop was aimed at identifying and documenting key science issues and strategies to fill hydrogeological knowledge gaps that will assist federal and state/territory governments in addressing groundwater management issues within the GAB, such as influencing the development of the next Strategic Management Plan for the GAB. This report summarises the findings out of the workshop.

Fresh groundwater stored in Australian coastal aquifers constitutes an important resource for humans and the natural environment. However, many Australian coastal aquifers are vulnerable to seawater intrusion the landward encroachment of seawater into coastal aquifers. This report is one technical assessment of the National Seawater Intrusion Project, aimed at characterising current and future seawater intrusion vulnerability of Australian coastal aquifers. This report outlines the development of a typological framework to categorise coastal aquifers and assist in their assessment of vulnerability. The report includes a characterisation of the different hydrogeological and climatic settings of Australia's coastal aquifer. Using public and confidential information, simplified cross-sectional conceptual models of case study areas were developed and aquifer parameters were tabulated for 28 case study areas (CSAs). Key hydrogeological characteristics are analysed and tabulated for use in other aspects of the overall vulnerability assessment.

Geoscience Australia (GA) was invited by Murray-Darling Basin Authority (MDBA) in 2010 to participate in an evaluation of the Intermap IFSAR (Interferometric Synthetic Aperture RADAR) data that was acquired as part of the Murray-Darling Basin Information Infrastructure Project Stage 1 (MDBIIP1) in 2009. This evaluation will feed into the business case for Stage 2 of the project. As part of the evaluation GA undertook the following: 1. A comparison of the IFSAR Digital Surface Model (DSM) and Digital Terrain Model (DTM) with a recent LiDAR acquisition, covering approximately 9000Km2 of the Lower Darling Region. It focused on assessment of the data over various land cover and terrain types and identified opportunities and issues with integrating IFSAR with LiDAR. 2. A comparison of the IFSAR Vegetation Canopy Surface (DSM minus DTM) with the Lower Darling LiDAR Canopy Elevation Model (CEM). 3. A comparison between currently mapped man-made and natural water bodies over the Murray-Darling Basin with the IFSAR derived products (water mask). 4. Application of the National Catchment Boundaries (NCBs) methodology to the IFSAR data and comparison with the delineated watersheds from PBS&J (Intermap's sub-contractor). This report outlines the findings of this evaluation based on the 4 items above MDBA requested.

We examine surface sediment and water column total nutrient and chlorophyll a concentrations for 12 estuaries with average water depths <4 m, and calculated sediment loads ranging from 0.2 to 10.8 kg m-2 year-1. Sediment total nitrogen, phosphorus and organic carbon concentrations vary inversely with sediment loads due to: (i) the influx of more mineral-rich sediment into the estuaries; and (ii) increasing sediment sulfidation. Sediment total organic carbon (TOC) : total sulfur (TS) and TS : Fe(II) ratios correlated to sediment loads because enhanced sedimentation increases burial, hence the importance of sulfate reduction in organic matter degradation. Curvilinear relationships were found between a weathering index and organic matter 13C in sediment, and sediment load. The rising phase of the curve (increasing weathering, lighter isotopic values) at low to intermediate loads relates to soil erosion, whereas regolith or bedrock erosion probably explains the declining phase of the curve (decreasing weathering, heavier isotopic values) at higher sediment loads. The pattern of change for water column total nutrients (nitrogen and phosphorus) with sediment loads is similar to that of the weathering index. Most water quality problems occur in association with soil erosion, and at sediment loads that are intermediate for the estuaries studied. Limited evidence is presented that flushing can moderate the impact of sediment loads upon the estuaries.

Petascale archives of Earth observations from space (EOS) have the potential to characterise water resources at continental scales. For this data to be useful, it needs to be organised, converted from individual scenes as acquired by multiple sensors, converted into ‘analysis ready data’ and made available through high performance computing platforms. Moreover, converting this data into insights requires integration of non-EOS datasets that can provide biophysical and climatic context for EOS. Digital Earth Australia has demonstrated its ability to link EOS to rainfall and stream gauge data to provide insight into surface water dynamics during the hydrological extremes of flood and drought. This information is supporting the characterisation of groundwater resources across Australia’s north and could potentially be used to gain an understanding of the vulnerability of transport infrastructure to floods in remote, sparsely gauged regions of northern and central Australia.

No abstract available

A PowerPoint presentation showing regional interpretations of data from the Frome airborne electromagnetic survey, presented at a workshop on 30 November 2011 at the University of Adelaide, South Australia