This research was first established during the ARC/NWC funded National Centre for Groundwater Research and Training (NCGRT) from 2009-2014, and is now a CWI Flagship Project.
Our recently published research
Key research papers on aquitard integrity at field scale and applications of the geotechnical centrifuge are listed below.
Bouzalakos, S., Crane R.A, McGeeney, D., Timms W.A. (2016) Stress-dependent hydraulic properties of clayey-silt aquitards in Eastern Australia. Acta Geotechnica, in press.
Timms WA; Crane R; Anderson DJ; Bouzalakos S; Whelan M; McGeeney D; Rahman PF; Acworth RI, 2016, 'Accelerated gravity testing of aquitard core permeability and implications at formation and regional scale', Hydrology and Earth System Sciences, vol. 20, no. 1, pp. 39 - 54, http://dx.doi.org/10.5194/hess-20-39-2016
Acworth RI; Timms WA; Kelly BFJ; Mcgeeney DE; Ralph TJ; Larkin ZT; Rau GC, 2015, 'Late Cenozoic paleovalley fill sequence from the Southern Liverpool Plains, New South Wales - implications for groundwater resource evaluation', Australian Journal of Earth Sciences, vol. 62, no. 6, pp. 657 - 680,http://dx.doi.org/10.1080/08120099.2015.1086815
Crane RA; CuthbertMO; Timms W, 2015, 'Technical Note: The use of an interrupted-flow centrifugation method to characterise preferential flow in low permeability media', Hydrology and Earth System Sciences, vol. 19, no. 9, pp. 3991 - 4000, http://dx.doi.org/10.5194/hess-19-3991-2015
David K; Timms W; Baker A, 2015, 'Direct stable isotope porewater equilibration and identification of groundwater processes in heterogeneous sedimentary rock', Science of the Total Environment, vol. 538, pp. 1010 - 1023, http://dx.doi.org/10.1016/j.scitotenv.2015.08.075
Jiang Z; Mariethoz G; Raiber M; Timms W; Cox M, 2015, 'Application of 1D paleo-fluvial process modelling at a basin scale to augment sparse borehole data: Example of a Permian formation in the Galilee Basin, Australia', Hydrological Processes, http://dx.doi.org/10.1002/hyp.10747
Research background
Lack of knowledge of the moisture content, storage, hydraulic conductivity and water quality of the many aquitards that overlie critical groundwater acquifers in Australia is a major threat to groundwater resource security. Aquitards surround many aquifers and because they have a comparatively high storage capacity, they will control the hydraulics of aquifers in the long term (Remenda, 2001).
Over very long time scales, diffusional losses mean that they also play a vital role in aquifer water quality. Neuzil (2003) stressed the importance of understanding the hydromechanical coupling within these systems and McMahon (2001) illustrated the importance of the mixing zone between aquifers and aquitards. Neuzil also noted that time constraints are a major problem in testing many of the physical properties of aquitards using field techniques such as drawdown tests.
The timescale problem can be overcome partly through the use of a large, high-speed centrifuge from which permeability and characteristic moisture curves of drill core samples can be derived. This sophisticated equipment also allows the extraction of water samples for chemical analysis and will be a unique resource in Australia.
The program is continuing to develop techniques to characterise both the hydraulics and chemistry (major anions, cations, stable isotopes) of low permeability strata with the view to better estimating the potential impact of water derived from these strata on groundwater quality and regional-scale aquifer dynamics. Various hydraulic, chemical and geophysical methods (e.g. microgravity methods for measuring subtle changes in water content of geologic materials) will be utilised and compared. Major advances in hydrochemistry will require techniques that allow better representative samples to be obtained (Glynn and Plummer, 2005) and this program directly addresses this urgent need.
Research personnel:
Completed personnel and students: