The groundwater in coastal zones is a critical freshwater resource relied upon by cities, agricultural areas, and rural communities across Australia. Coastal groundwater is threatened by saltwater penetrating from the sea (seawater intrusion) and serves as a pathway (through submarine groundwater discharge) for the transport of land-based pollutants to marine ecosystems. The study of coastal groundwater requires consideration of complicated processes arising from tidal mixing and the density difference between freshwater and seawater.

Researchers within NCGRT are leaders in the advancement of coastal groundwater research, including the understanding of seawater intrusion, tidal propagation into aquifers, geochemical processes, and estuary-aquifer interactions. Our research includes continental aquifers that have coastal boundaries and the highly threatened fresh groundwater of island aquifers, including those of neighbouring Pacific nations. Methods of investigation include intensive field measurements using a wide variety of physical, chemical and geophysical techniques, numerical simulation, analytical mathematics, and laboratory sand tank experimentation. Coastal groundwater systems and groundwater-dependent ecosystems in South Australia, Queensland, New South Wales, and Western Australia have been characterised by NCGRT researchers to support management decision making.

Selected Publications

Acworth RI, Andersen MS and Dasey G (2020) Investigation of the changing characteristics of the saline interface beneath an ocean beach using time-lapse physical and chemical methods. Hydrogeology Journal, 28, 1695-1719. https://doi.org/10.1007/s10040-020-02155-5.

Bryan E, Meredith KT, Baker A, Post VE and Andersen MS (2016) Island groundwater resources, impacts of abstraction and a drying climate: Rottnest Island, Western Australia. Journal of Hydrology, 542, 704-718. https://doi.org/10.1016/j.jhydrol.2016.09.043.

Hofmann H, Newborn D, Cartwright I, Cendón DI and Raiber M (2020) Groundwater mean residence times of a subtropical barrier sand island. Hydrology and Earth System Sciences, 24, 1293-1318. https://doi.org/10.5194/hess-24-1293-2020.

Sadat-Noori, M, Anibas C, Andersen MS, and Glamore W (2021) A comparison of radon, heat tracer and head gradient methods to quantify surface water - groundwater exchange in a tidal wetland (Kooragang Island, Newcastle, Australia). Journal of Hydrology, 598, 126281. https://doi.org/10.1016/j.jhydrol.2021.126281.

Solórzano-Rivas SC, Werner AD, and Irvine DJ (2021) Estimating hydraulic properties from tidal propagation in circular islands. Journal of Hydrology, 598, 126182. https://doi.org/10.1016/j.jhydrol.2021.126182.

Werner AD, Sharp HK, Galvis SC, Post VEA, and Sinclair P (2017) Hydrogeology and management of freshwater lenses on atoll islands: Review of current knowledge and research needs. Journal of Hydrology, 551, 819-844. https://doi.org/10.1016/j.jhydrol.2017.02.047.