Multi-physics, inter-disciplinary approaches for groundwater system investigations and hydrogeological assessments in Northern Australia

Abstract

The development of Northern Australia has been identified as a national priority, with water availability being fundamental to economic development. Surface water options are limited hence identification of new groundwater resources and water banking options is essential. Over the past four years, Geoscience Australia, in concert with State and Territory partners, has been involved in focussed groundwater investigations in 10 geographic areas as well as broader regional investigations (Figure 1). New data acquisition has included airborne electromagnetics (AEM); drilling (sonic, rotary mud, air core and diamond); slug and bore testing; ground geophysics (surface nuclear magnetic resonance, microgravity, passive seismic, seismic reflection and ground penetrating radar); borehole geophysics (induction, spectral gamma, nuclear magnetic resonance); hydrochemical and hydrodynamic analysis; age dating of water and landscape materials; and mapping (geomorphic, morphotectonic, regolith, geological and hydrological). These investigations inform hydrogeological assessments and water allocation planning.Overall, this multi-physics, inter-disciplinary approach has been critical in enabling the rapid identification and assessment of significant new potential fresh groundwater resources within tectonically inverted Palaeozoic sedimentary basins in the Fitzroy Basin (WA), Bonaparte Basin (WA-NT), Wiso Basin (NT), and Southern Georgina Basin (NT), and helped define the extents of a new groundwater resource for the town of Alice Springs (NT). Potential brackish and saline groundwater resources have also been identified in Cenozoic paleovalleys and Tertiary and Paleozoic Basins.