Development of an agreed set of climate change projections for South Australia
GOYDER PROJECT NUMBER: C.1.1
Climate change will bring about significant changes to the capacity of, and the demand on, South Australia’s water resources. As the future changes to these water resources cannot be measured in the present, hydrological models are critical in the planning required to adapt the State’s water resource management strategies to future climate conditions. Climate projections derived from global climate models are typically on the spatial scale of a state or a region and on temporal scales that are typically monthly at best. There is a missing link between the outputs of regionally-downscaled global climate model projections for time horizons of 2030, 2050 and beyond, and the climate data requirements of hydrological models. Past and ongoing hydrological modelling efforts within South Australian State Government departments, universities and research organisations have been carried out individually rather than being coordinated across organisations, resulting in a lack of an agreed set of downscaled time series.
This project, in close consultation with end users, will develop an agreed set of downscaled climate projections for South Australia to support proactive responses to climate change in water resource planning and management. Distributions of environmental time series, including rainfall, temperature and potential evapotranspiration will be developed from a suite of agreed GCM downscaled projections for the Onkaparinga catchment, which will also account for current climate variability (including trend and seasonality) and the influence of known climate drivers. Once the methodology on the Onkaparinga case study catchment has been validated, the work will be expanded to provide downscaled climate projections for all eight South Australian NRM Board areas, using the most up-to-date climate information coming from the IPCC and Australian climate initiatives. The project’s integration component ensures that the required interconnections between each task are realised and that there is an integration of this work into the other three Goyder Institute Themes.
The Bureau of Meteorology is using the new understanding of El Nino-Southern Oscillation (ENSO) impact on Australian climate coming through the Indian Ocean to improve their seasonal prediction. The project team has purchased Daily rainfall gridded data, Daily Evaporation, Hourly Temp, humidity, pressure, and Daily Wind data from the Australian Bureau of Meteorology. Four project workshops have been held throughout 2010-11.
Next Steps/Future Work
The climate driver work will be used to determine how much of the observed climate change over SA is attributable to climate and climate variability, and evaluate how the impacts of climate drivers are manifested in terms of changes in extreme events. The system for benchmarking climate models will be applied to AR5 simulations as they become available. The GLIMCLIM precipitation simulations for historical climate will be assessed and GLIMCLIM and NHMM predictions will be compared for the Onkaparinga catchment. The project will conduct initial hydrological model calibration and evaluation using BATEA and commence the development of runoff error models for inclusion into BATEA calibrations.