The challenge
Monitoring our groundwater and resources that depend on it
We use monitoring data to establish the baseline of groundwater quantity and quality. Ongoing assessment ensures sustainable use and early detection of water quantity and quality changes. Monitoring strategies need to be cost sensitive and critical. This guarantees the collected datasets are relevant for the assessment and management of groundwater resources.
The monitoring of groundwater and its dependencies, such as ecosystems or ground deformation, is most often undertaken using direct and derived field measurements. While the characterisation of the aquifer system ( hydraulic parameters, aquifer compressibility) relies on derived information, the system behaviour (groundwater heads, water quality, environmental tracers, land subsidence) is usually measured directly. Such data, however, is expensive and not always available at sufficient spatial and temporal resolution. Geophysics, remote sensing and other data sets also provide a highly valuable and cost-efficient source of information to fill gaps in groundwater monitoring data. The type and amount of monitoring data required to inform management decisions and constrain modelled predictions of management interest vary considerably depending on the objectives of monitoring.
Our response
Cost-effective new methods and tools provide maximum return
We are developing methods that help to devise optimal and cost-effective strategies for groundwater monitoring that identifies the type, number and locations of groundwater observations that can provide maximal return on investment for a given objective(s). We are also inventing new techniques to extract as much reliable information as possible for a given set of monitoring data.
These methods and tools facilitate smart data acquisition – identifying both the most appropriate data type and the optimal locations/times for sampling. The techniques can be used to develop effective new monitoring networks or to improve existing monitoring programs and can be tailored to regional or local areas of interest. They help to ensure that the maximum knowledge gain is obtained from a fixed field campaign budget.
We work alongside partners such as State and Federal water management jurisdictions and regulators, such as the New South Wales Department of Planning, Industry and Environment (NSW-DPIE), alliances like the Gas Industry Social and Environmental Research Alliance (GISERA), industry, and land holders to apply these tools and methods for informing groundwater monitoring and management decisions.
The results
Evidence for impact assessment, response management and early warning
Our research has been used to inform groundwater monitoring strategies to better assess the impacts of onshore gas development in Eastern Australia. Our methods have also been used to identify areas with high likelihood of finding groundwater in South Australian regions where field data sets are highly sparse. Our methods allow a cost-effective and adaptive monitoring strategy that support evidence-based decision making for sustainable water resource management.
Novel space-borne platforms provide new opportunities in quantitative groundwater monitoring. For example, geodetic ground deformation and time-variable gravity data (GRACE) inform on groundwater storage change at different scales. While they are both highly cost-effective and able to cover large areas, their resolution and unusual sensitivity require expertise for integration into typical groundwater monitoring schemes. We are using spaceborne radar imagery (InSAR) from a diversity of orbital platforms, including our in-house radar NovaSAR, to monitor groundwater dependencies such as land subsidence and health of Groundwater-Dependant Ecosystems (GDEs). In turn, monitoring these groundwater dependencies allow us inferring groundwater storage anomalies.
Our space-borne monitoring systems are used to create evidence base and decision-support basis for groundwater response management and as early warning systems for land holders and regulators. Future risk assessments of the feedback of land deformation on surface-water systems, such as the Murray Darling Basin, will benefit from increased confidence on improved deformation observations and models that are informed and constrained by those data. This will become exceedingly more important as pressure on groundwater extractions will most likely increase as a result of climate-change related surface-water shortage.