Groundwater sensitivity to climate across Australia
- 1Department of Infrastructure Engineering, University of Melbourne, Melbourne, Australia (xinyangf1@student.unimelb.edu.au)
- 2Department of Civil Engineering, Monash University, Melbourne, Australia (tim.peterson@monash.edu)
- 3Climate and Energy College, University of Melbourne, Melbourne, Australia
- 4Institute of Applied Geosciences, Division of Hydrogeology, Karlsruhe Institute of Technology, Karlsruhe, Germany
- 5School of Earth, Atmosphere and Environment, Monash University, Melbourne, Australia
- 6Securing Antarctica’s Environmental Future, Monash University, Melbourne, Australia
Climate change is projected to significantly influence groundwater resources in many regions around the world. However, the Fifth Assessment Report of the IPCC states that it is still poorly understood how groundwater level and recharge has and will be impacted by climate change due to the limited groundwater observation records and the confounding influence from multiple drivers, such as climate, pumping, and land cover change. This study aims to understand the risks to groundwater by estimating the sensitivity of groundwater level and recharge across Australia to climate variability.
To achieve this we firstly used HydroSight, a time-series groundwater hydrograph modeling toolbox, to identify those sites having experienced minimal influence from anthropogenic impacts such as groundwater pumping or land cover changes. A total of 5077 sites were modeled, from which 336 sites were identified as having groundwater levels primarily driven by climate variations alone, with 245 sites located in Victoria. HydroSight groundwater simulations were then undertaken and used within multivariate regression to estimate the groundwater sensitivity to precipitation and potential evapotranspiration.
Results show that around one-fifth (n=72) sites are highly sensitive to changes in precipitation, with a sensitivity of more than 0.5m change in groundwater level per 1 percent shift in precipitation. The highly sensitive sites are mostly located in southwest Western Australia and southeastern Australia. The groundwater recharge sensitivity in Victoria shows a high spatial consistency which gradually increases from North to South. By quantifying the sensitivity of groundwater to historic climate variations, this study allows the identification of regions most vulnerable to climate change throughout Australia and hence a more targeted future climate adaptation strategy.
How to cite: Fan, X., Peterson, T., Henley, B., and Arora, M.: Groundwater sensitivity to climate across Australia, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4, https://doi.org/10.5194/egusphere-egu22-4, 2022.
