Nuclear geophysiology: stable water isotopes as evaluators of hydroclimate predictions in the Murray-Darling basin

Abstract

Isotopic data from two end-range and one central aquifer in the Murray Darling Basin are used to determine precipitation intensity thresholds for evaluation of GCM predictions. Applying these to ‘good’ and ‘poor’ Atmospheric Model Intercomparison Project (AMIP) simulations of the Murray Darling gives rise to large differences in rainfall amount (30% to 62%). Selecting only ‘good’ models shows a >150mm annual groundwater recharge loss in El Niño cf. La Niña climates. These isotopic techniques are applicable to future model scenarios of basin-scale hydrology, especially in difficult to simulate semi-arid basins.