Chris Turnadge

Doctoral candidate in Adjoint Solutions for Model Sensitivities

I am a hydrogeologist with a broad range of theoretical and applied experience. My past work has involved the development of forward models of groundwater flow and solute transport using a range of methods including parameter estimation via model inversion. I have also characterised modelled system responses using a range of sensitivity and uncertainty analysis approaches. Recently, I have focused on the use of time and frequency domain methods to estimate subsurface hydraulic properties from groundwater pressure responses to various periodic passive forcings.

My doctoral research is focused on the derivation, implementation and effective communication of adjoint solutions for the sensitivities of saturated groundwater flow solutions. These will facilitate more efficient computation of model sensitivities, which will in turn improve the efficiency of model inversion algorithms.

My contribution to Deep Earth Imaging involves the development of periodic methods based on active forcings for the hydraulic testing of groundwater wells. This research contributes to both the Imaging and Conceptualisation pillars of research.

Within Deep Earth Imaging my research is part of the System Conceptualisation research program.


Technical skills

  • Forward modelling of saturated and unsaturated flow and solute transport using analytical, semi-analytical and numerical approaches
  • Local and global sensitivity analysis using direct differentiation, perturbation and adjoint state approaches
  • Model prediction uncertainty analysis using linear and nonlinear methods
  • Field sampling and model-based interpretation of environmental tracers and hydrochemical constituents in ground and surface waters
  • Time and frequency domain methods of time series analysis using Fourier analysis and regression deconvolution


Professional experience

October 2011 – Present
Hydrogeologist Researcher, CSIRO Land and Water



BSc (Honours, first class), Flinders University, South Australia (2010)


Selected publications

Turnadge, C., Crosbie, R. S., Barron, O., & Rau, G. C. (2019). Comparing Methods of Barometric Efficiency Characterization for Specific Storage Estimation. Groundwater, 57(6), 844-859.

Peeters, L. J. M., & Turnadge, C. (2019). When to account for boundary conditions in estimating hydraulic properties from head observations?. Groundwater, 57(3), 351-355.

Crosbie, R. S., Doble, R. C., Turnadge, C., & Taylor, A. R. (2019). Constraining the magnitude and uncertainty of specific yield for use in the water table fluctuation method of estimating recharge. Water Resources Research, 55(8), 7343-7361.

Smerdon, B. D., & Turnadge, C. (2015). Considering the potential effect of faulting on regional-scale groundwater flow: an illustrative example from Australia’s Great Artesian Basin. Hydrogeology Journal, 23(5), 949-960.

Turnadge, C., & Smerdon, B. D. (2014). A review of methods for modelling environmental tracers in groundwater: Advantages of tracer concentration simulation. Journal of Hydrology, 519, 3674-3689.



Australian Groundwater Conference, Brisbane, Australia, November 24-27, 2019

Modflow and More 2019, Golden, Colorado, USA, June 2-5, 2019.