Curtin/CSIRO Geophysics Seminar, 2nd June 2022
Water for food, desalination and how to find fractured rock aquifers with geophysics and drilling; examples from the Wheatbelt of Western Australia
Date: Thursday, 2nd of June, 2022
Time: 11:00 AM – 12:00 PM
Location: CSIRO/ARRC Auditorium, 26 Dick Perry Avenue, Kensington
Authors/Research Team: Brett Harris, Richard George, Richard Chopping, and Matt Becker
Presenter: Brett Harris, Professor, Discipline Lead – Exploration Geophysics, WASM: Minerals, Energy and Chemical Engineering, Curtin University
Supply of high-quality water is critical for global food production. This challenge can be acute in arid to semi-arid regions. New water treatment technologies such as solar driven desalination have potential to transform brackish groundwater into water suitable for food production at reasonable cost. Does this mean that brackish groundwater held in fractured rock aquifers could be a new long-term water resource?
Fractured rock aquifers can be productive but are notoriously high-risk drill targets. Integration of geophysics and exploratory drilling will be needed for: (i) fractured rock aquifer prospectively mapping, (ii) targeting of wells at farm scale, and (iii) rapid quantification of groundwater resources across a wide range of water qualities. We will consider the status of our knowledge for targeting fractured rock aquifers and the criteria for prospectivity mapping with examples from the Wheatbelt of Southwestern Australia. Here fault systems many hundreds of kilometres long are clearly observed in magnetic imaging, but which of these structures are more likely to host viable aquifers?
We review apparent temporal and spatial association of faults and fractured rock aquifers. Finally, we review the integration of drilling and geophysics needed to facilitate distributed water supply from fractures in the context of: (i) dry land salinity, (ii) solute concentration distribution, (iii) relationships between fractured rock aquifers and water stored in regolith/cover and (iv) requirements for brine disposal from desalination processes.