Author(s): C. Petheram; P. Rustomji; J. Vleeshouwer; R. Cresswell; F. Chiew
Linked Author(s): Cuan Petheram
Keywords: Rainfall-runoff modelling; Regionalisation; Climate change; Tropical
Abstract: The prolonged drought across southern Australia and climate change predictions of a drier future have led to renewed interest in water resource development of northern Australia. Using data from 105 catchments in tropical Australia, five daily rainfall-runoff models and three methods of regionalising model parameters were compared. Under prediction mode there was no difference in model performance. The adoption of multiple-criteria to select an optimal parameter set resulted in an improved ability to simulate low flows, with no loss in predictive capacity for higher flows. An educated transposition of ‘intact' parameter sets between gauged and ungauged catchments was better than random assignment of ‘intact' model parameter sets, while assigning model parameter sets on the basis of spatial proximity out-performed physical similarity methods. The best performing multi-model ensemble and the best method of parameter regionalisation were used to model runoff under current and future (2030) climates across the Timor Sea, Gulf of Carpentaria and northern North East coast drainage divisions. The mean annual runoff results under current and future climates are presented. The future climate series used for the modelling is informed by projections from 15 global climate models. There is considerable uncertainty in the future runoff projections, mainly because of the uncertainty in the future rainfall projections.
Year: 2011