The Australian Government, through the National Water Infrastructure Development Fund, commissioned Geoscience Australia to undertake a 3-year project ‘Assessing the Status of Groundwater in the Great Artesian Basin’. The overall aim of the project was to analyse existing and new geoscientific data acquired by the project to improve understanding of the hydrogeological system and water balance in the GAB. In conjunction, the project assessed satellite based technologies for monitoring groundwater storage and level change. This talk will discuss some of the key results of the project. These include: an updated hydrogeological framework for the GAB, mapping aquifer and aquitard properties, geometry and extent; revised groundwater recharge rate estimates in the eastern GAB groundwater intake beds; new groundwater system conceptual models of groundwater recharge processes and groundwater flow; an assessment of the Gravity Recovery and Climate Experiment (GRACE) satellite derived groundwater storage change estimates for the GAB; and Interferometric Synthetic Aperture Radar (InSAR) satellite data, for detecting changes in groundwater levels.

Salinity of groundwater directly affects its suitability for different uses, from human consumption, agricultural use, to mineral and energy extraction. Traditionally, direct measurements of groundwater salinity at monitoring bores have been used to create salinity maps. However, drilling is expensive and logistically challenging, while leaving us with a small set of salinity measurements over large areas. Airborne electromagnetic (AEM) surveying provides a cost effective solution to this problem. We have developed a scripted geostatistical methodology, which can be repeated on a computer cluster as new AEM data are acquired or boreholes are drilled. We also provide uncertainties on the knowledge gained, allowing remote communities to manage their land and water resources effectively.

Rapid population growth and an increasing demand for water has been depleting groundwater resources in the Central Valley of California for decades. The lack of sufficient ground monitoring networks poses serious challenges to water management efforts and puts the sustainability of groundwater resources at risk. This seminar will demonstrate how the satellite remote sensing techniques of Interferometric Synthetic Aperture Radar (InSAR) and the Gravity Recovery and Climate Experiment (GRACE) can be applied to monitor groundwater resources and aquifer response to drought. The final part of this seminar will describe how GA is currently trialling the demonstrated methods as remote groundwater monitoring tools in the Great Artesian Basin of Australia.