Preface: Advances in hydrogeologic understanding of Australia's Great Artesian Basin.

Published in the special issue "Advances in hydrogeologic understanding of Australia's Great Artesian Basin" The special issue starts with a comprehensive review of the GAB by B Habermehl b that includes the history of the GAB discovery and its exploration, scientific investigations (hydrogeology, hydrochemistry, isotope hydrology, groundwater modelling) and governance, and that summarizes the most recent knowledge of the GAB as a complex groundwater socio-ecological system. The GAB springs appear to be discharging water predominantly from the main GAB aquifer in the region - the J Aquifer. How much water currently recharges GAB aquifers and how much is lost in surface and shallow subsurface processes, have been long-standing questions that need to be considered when modelling and managing GAB groundwater resources. [Extracted from the article]