Impact of climate change on Australia's surface water resources

Global climate change caused by rising atmospheric concentrations of carbon dioxide (CO2) and other trace gases may have significant impacts on the timing and magnitude of rainfall, soil moisture, evapotranspiration, and streamflow. These impacts have important implications for future water resources planning and management. This paper investigates the potential impact of climate change on Australia's surface water resources. Six catchments are selected from a variety of climatic and hydrologic regimes. A stochastic weather generator is used to derive 1000-year daily weather sequences corresponding to present day and future (doubled CO2) climates. The synthetic daily weather data are used to drive two conceptual rainfall-runoff models (IHACRES and a generalised version of Boughton's SFB Model) that have been calibrated using historical climate and runoff data to determine the potential impact of climate change on streamflow regimes. The most prominent impacts are sizeable changes in median monthly runoff magnitudes during the high runoff periods of the year and sizeable increases in annual maximum monthly runoff. This indicates a possible increase in flood risk.