The 'River Murray Corridor (RMC) Salinity Mapping Project', provides important new information in relation to salinity hazard and management along in a 20 km-wide swath along a 450 km reach of the River Murray. The project area contains iconic wetlands, national and state forest parks, irrigation and dryland farming assets and the Murray River, significant areas of which are at risk from increasing salinisation of the River, the floodplain, and underlying groundwater resources. The project utilised a hydrogeological systems approach to integrate and analyse data obtained from a large regional airborne electromagnetic (AEM) survey (24,000 line km @ 150m line-spacing in a 20 km-wide swath along the Murray River), field mapping, and lithological and hydrogeochemical data obtained from drilling. New holistic inversions of the AEM data have been used to map key elements of the hydrogeological system and salinity extent in the shallow sub-surface (top 20-50 m). The Murray River is known to display great complexity in surface-groundwater interactions along its course. Electrical geophysical methods (such as AEM) are able to map surface-groundwater interaction due to the contrast between (electrically resistive) fresh water in the river, and (electrically conductive) brackish to saline groundwater in adjacent sediments. The location of significant river flush zones is influenced both by underlying geology and the location of locks, weirs and irrigation districts. The study has also identified significant areas of high salinity hazard in the floodplain and river, and quantified the salt store and salt load across the floodplain. The study has also identified sub-surface factors (including saline groundwater, shrinking flush zones, declining water tables) linked to vegetation health declines.

Legacy product - no abstract available

This is the second quarterly report on the progress of the Murray Basin Hydrogeological Project. In this report an outline map of the basin is included to indicate where activities have occurred during the quarter, and the general statement describing the Project forms the appendix. Participating organisations are the Geological Survey of New South Wales, the Water Resources Commission of New South Wales, the Geological Survey of Victoria, the State Rivers and Water Supply Commission of Victoria, the Department of Mines and Energy of South Australia, and the Bureau of Mineral Resources.

The Calivil Formation was explored for water resource and Managed Aquifer Recharge targets, combining new and established techniques in an integrated and multidisciplinary manner.

There is increasing demand from policy makers for high levels of certainty before committing to decisions on water security infrastructure. This demand for higher certainty in groundwater model predictions has provided an impetus for new hydrogeological research directions. This has included a renewed impetus in the search for technologies and methods to aid rapid groundwater resource assessment. Critical measurements used to parameterise groundwater models include effective porosity and hydraulic conductivity measurements. Typically, values for effective porosity are derived by lithological comparisons with published data, and measurements of hydraulic conductivity acquired by limited constant head pumping tests or slug tests. Look-up tables are used for deriving effective porosity as a surrogate for expensive and time consuming laboratory measurements of cores that may be biased by sampling, and the difficulty of making measurements on unconsolidated materials. However, pump tests are costly and time-consuming, with environmental permissions for disposal of produced waters increasingly difficult to obtain. Nuclear Magnetic Resonance (NMR) can provide a direct measurement of the presence of water in the pore space of aquifer materials. The detection is possible due to the nuclear magnetization of the hydrogen (protons) in the water. The NMR measurement is the basis of MRI (magnetic resonance imaging) in medical applications, and geophysical logging applications within consolidated sediments for the petroleum industry. In the Darling River floodplain, NMR data were acquired in 26 boreholes in a 4-week period. Effective porosity values were derived directly from the NMR data, and hydraulic conductivity values were calculated using empirical relationships calibrated and verified with limited laboratory permeameter and field aquifer tests.

This study reports the findings of salt store and salinity hazard mapping for a 20-km wide swath of the Lindsay - Wallpolla reach of the River Murray floodplain in SE Australia. The study integrated remote sensing data, an airborne electromagnetics (AEM) survey (RESOLVE frequency domain system), and lithological and hydrogeochemical data obtained from a field mapping and drilling program. Maps of surface salinity, and surface salinity hazard identified Lindsay and Wallpolla Islands, and the lower Darling Floodplain as areas of high to extreme surface salinity hazard. In the sub-surface, salt stores were found in general to increase away from drainage lines in both the unsaturated and saturated zones. Beneath the Murray River floodplain, salt stores in both unsaturated and saturated zones are high to very high (100 to 300t/ha/m) across most of the floodplain. Sub-surface salinity hazard maps (incorporating mapped salt stores and lithologies, depth to water table and the hydraulic connectivity between the aquifers), identify Lindsay and Wallpolla Islands; the northern floodplain between Lock 8 and Lock 7; and northern bank of Frenchman's Creek as areas of greatest hazard. Overall, the new data and knowledge obtained in this study has filled important knowledge gaps particularly with respect to the distribution of key elements of the hydrostratigraphy and salinity extent across the Murray River and lower Darling floodplain. These data are being used to parameterise groundwater models for salinity risk predictions, to recalculate estimates of evapotranspiration for salt load predictions, address specific salinity management questions, and refine monitoring and management strategies.

Under the Community Stream Sampling and Salinity Mapping Project, the Australian Government through the Department of Agriculture, Fisheries and Forestry and the Department of Environment and Heritage, acting through Bureau of Rural Sciences, funded an airborne electromagnetic (AEM) survey to provide information in relation to land use questions in selected areas along the River Murray Corridor (RMC). The proposed study areas and major land use issues were identified by the RMC Reference Group at its inception meeting on 26th July, 2006. This report has been prepared to facilitate recommendations on the Robinvale - Boundary Bend study area. The work was developed in consultation with the RMC Technical Working Group (TWG) to provide a basis for the RMC Reference Group and other stake holders to understand the value and application of AEM data to the study area. This understanding, combined with the Reference Groups assessment of the final results and taking in account policy and land management issues, will enable the Reference Group to make recommendations to the Australian Government.

Final demonstration site report for the Murchison region completed as part of the Palaeovalley Groundwater Project

Geoscience Australia (GA) has developed an interactive 3D virtual globe viewer to facilitate effective communication of geoscience data and scientific findings to a wide range of stakeholders. The interactive virtual globe is built on NASA's open source World Wind Java Software Development Kit (SDK) and provides users with easy and rich access to geoscientific data. The tool has been used to launch a number of national and regional datasets, including sub-surface seismic and airborne electromagnetic data (AEM) in conjunction with other relevant geoscience data. For the Broken Hill Managed Aquifer (BHMAR Project, there was a requirement to further develop the existing viewer platform in order to display complex 3D hydrogeological, hydrogeophysical and hydrogeochemical data (points, lines, 2D surface and 3D shapes). The final product includes support for a variety of geo-referenced raster data formats, as well as vector data such as ESRI shapefiles; native support for a variety of GOCAD data types including TSurf, SGrid, Voxet and PLine. It also supports well and borehole data including attribute-based styling of log features and the ability to include legends and descriptions of data within the user interface. An easy-to-use interface has been customised for navigation of data in 3D space using a virtual globe model, with powerful keyframe based animation tools used to generate flythrough animations for use in knowledge communication workshops. The products will be distributed as data layers via the internet and as a stand alone DVD package.

Development of coal mines and coal seam gas (CSG) resources can have significant impacts on groundwater systems, hydrogeological processes and the surface environment. The Australian Government, via the Office of Water Science, Department of Sustainability, Environment, Water, Population and Communities has funded a program to investigate the potential impacts of the development of new coal mines and CSG production in eastern Australia. The Laura Basin was investigated as part of this program because: -Drainage systems discharge to the World Heritage-listed Great Barrier Reef Marine Park; -Almost half of the basin area is National Park; -Over half of the basin is covered by Indigenous Land-Use Agreements; -Most available land is tenemented for coal exploration and a significant black coal resource occurs at Bathurst Range (47 million tonne resource of coking coal); -There are many significant wetlands and threatened species in the region; -There was previously a relatively poor understanding of groundwater characteristics across the basin. These include temporal variations in groundwater balance components, groundwater flow directions, aquifer connectivity, groundwater quality and surface water-groundwater connectivity. A desktop study was undertaken, bringing together diverse data sets, to develop a basin-scale understanding of the hydrogeology of the Laura Basin and undertake a regional-scale water balance components analysis. The potential for geological structures to impact groundwater flow systems and interactions between aquifers or between surface water and groundwater systems was considered. The study also identified water dependent assets and potential pathways for impacts of coal mining to these assets. This project highlights the limitations posed to regional assessments by sparse data and provides recommendations for targeted investigation to improve scientific understanding. Importantly, data coverage is highlighted with reference to its adequacy for providing a baseline against which change due to future land use/ resource development might be assessed. This abstract was developed as part of the National Collaborative Framework Project- Hydrogeological Characterisation of the Laura Basin