Resilience, stress and sustainability of alluvial aquifers in the Murray-Darling Basin, Australia: Opportunities for groundwater management
Rodrigo Rojas, Dennis Gonzalez, Guobin Fu
Abstract
Main alluvial aquifers of the Murray-Darling Basin (MDB), Australia Around 75% of total metered groundwater use within Australia’s Murray-Darling Basin (MDB), arguably the nation’s most important food and fibre production region, is extracted from eight main alluvial aquifer systems. To date, regional-scale analyses of groundwater resilience, stress and sustainability for the region have not been completed. This study provides a systemic overview of the main alluvial systems anchored in these concepts. To achieve this, we combined three lines of evidence encompassing: a) long-term trend analysis of groundwater levels; (b) calculation of groundwater footprint indices considering volume and quality; and (c) an explicit comparison of groundwater management areas in terms of groundwater usage, sustainable use, storage volumes, presence and diversity of groundwater-dependent ecosystems (GDEs), and buffering capacity to absorb changes in recharge rates. The novelty of our work rests upon an integrated assessment of these three lines of evidence incorporating twelve different metrics to prioritise future groundwater management efforts. Results indicate that eleven out of twenty-two groundwater management areas show resilience, stress and/or sustainability issues, and a further two with emergent issues. Efforts to improve our understanding and management of these key groundwater resources would be most effective if focussed on these areas.