Assessing Hydrological Connectivity in Australia Through Noble Gas Data

Gorge in the Beetaloo sub-basin where the project team have collected samples for analysis. Image: Dr Matthias Raiber

This Project aims to demonstrate the value of combining novel noble gas analysis facilities at CSIRO and the University of Adelaide (UoA) to strengthen our understanding of complex groundwater systems. This will underpin long-term water security in Australia and, in turn, support the growing water needs of the mineral, energy, and agricultural industries.

Overview

Hydrological and hydrogeological connectivity in groundwater and surface water systems describes how readily water can move within different parts of aquifers and between groundwater and surface water systems such as springs, rivers and lakes. It assesses the degree of water-mediated transport of matter, energy, and organisms within or between elements of the hydrological cycle. Typically used to understand variations in run-off and run-on, at a broader scale, it provides crucial information that impacts everything from water quality to ecosystem health.

Spearheaded by Dr Matthias Raiber from CSIRO’s Sustainable Groundwater Futures team, this project aims to collect groundwater samples from two proof-of-concept areas on First Nations Country: Beetaloo Sub-Basin in the Northern Territory and the K’gari World-Heritage sand island on Queensland. The springs and lake systems in these two areas were selected due to their cultural significance in areas of gas exploration, as well as contrasting hydrogeological environments where the noble gas tracers can cover full-time range testing. The team will analyse samples through the Atom Trap Trace Analysis (ATTA) technology at UoA, and publish the findings via respective data portals to facilitate the inclusion of groundwater environmental tracer data for traditional owners and industry users.

“There are only three labs in the world with this noble gas tracer capacity, including labs in Germany and China.
The ability to measure both stable and radioactive noble gases in water samples in Australia allows us to not only understand how old groundwater is, from decades and centuries up to hundreds of thousands of years, but also identify if deep aquifers are connected to springs and surface water systems.” - Dr Matthias Raiber

The Challenge

Despite hydroconnectivity between aquifers, springs and surface water systems being a cornerstone of effective water management, environmental conservation, and sustainable development, adequate information about hydrological connectivity is lacking in many areas. Geochemical reactions can influence traditional groundwater tracers such as 14C and 36Cl, whereas stable noble gases such as helium and radioactive noble gases such as 39Ar and 81Kr are inert, meaning they are less affected by geochemical reactions. This makes stable and radioactive noble gases an ideal tracer to complement other environmental tracers such as 14C and 36Cl.

In this project, the team is testing a new field collection technique that requires a much smaller sample volume, thus making sampling easier and increasing the uptake of this technique. The combination of traditional tracers such as tritium, 14C, and 36Cl with noble gases can support the governance and management of ecological systems, particularly decision-making for land-use and resource development activities. The inclusion of groundwater sampling in platforms like AusGeochem and the CSIRO data access portal will enable the development of new data models, allowing more of Australia’s groundwater science community to participate more actively in research and development.

Expected Outcomes

Field collection of water noble gas samples
Gas separation and purification of radioactive noble gas samples
Analysis of water samples in Australia (including 3H, 14C, 36Cl and stable noble gases)
Analysis of radioactive noble gas samples (University of Adelaide and at the University of Science and Technology of China in Hefei)
Final data delivery through AusGeochem database and CSIRO data portal

What are the benefits?

Enhanced environmental monitoring: Collections of high-quality tracer data, including stable noble gas and radioactive noble gas isotopes, will provide a better understanding of inland and coastal aquifers by providing baseline data and monitoring climate change impacts and subsequent mitigation actions.
Improved sampling and processing techniques: Using a new gas separator for radioactive noble gases will demonstrate the benefits of small-volume sampling, enabling groundwater stakeholders to participate in research more actively.
Broader research partnerships: The creation of new groundwater data sets will help provide greater context to research, including knowledge sharing with adjacent fields that rely on groundwater assessment and prediction.

Who will benefit

Researchers, government agencies, and industry professionals involved or are interested in groundwater sampling and hydrological processes.

Access

Lab access: The broader research community has access to the ATTA radioactive noble gas analytical facility at UoA and the stable noble gas laboratory at CSIRO.
Data access: When available, groundwater sampling data will be made available via AusGeochem and the CSIRO data access portal.

Acknowledging AuScope

This project was made possible by support from the National Collaborative Research Infrastructure Strategy (NCRIS) through AuScope. Acknowledging AuScope and NCRIS helps us demonstrate the value of shared research infrastructure, ensuring continued support and resources for the research community.

If you helped deliver this project or have benefited from its outputs, please credit AuScope so we can include your work in our impact reporting. For examples of acknowledgment, please visit our ‘How to Acknowledge AuScope’ page.

We’d love to see your work—please tag us on social media using:

@auscope | #AuScopeImpact | #NCRISimpact

Project Name
Assessing Hydrological Connectivity in Australia Through Noble Gas Data

Project Lead

Featured