Understanding climate processes in the Murray-Darling Basin: utility and limitations for natural resources management

Ocean-atmosphere processes causing variations in the climate of Australia's Murray-Darling Basin (MDB) occur on time scales from days to centuries, all are important, and none are likely to act in isolation. Instead, interactions between all hydroclimatic drivers, on multiple time scales, are likely to have caused the variations observed in MDB instrumental records. The source and relative importance of each climate driver varies due to the geographic spread of the Basin from the subtropics to the middle latitudes. Such differences were highlighted during the period from 1997–2010 when the southern MDB experienced prolonged and severe dry conditions, while decadal-scale rainfall in the northern MDB remained close to normal. Although recent studies have provided insights into possible mechanisms, the cause of this recent drying is still uncertain. To this end, this paper addresses the current state of knowledge about the processes causing climate variations in the MDB and the utility and limitations of this knowledge for natural resources management.