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Summary of datasets for classification of river reaches in the Murray–Darling Basin and changes in the flow regime over the past few decades

The hydrology theme enhanced hydrological knowledge and advanced modelling capacity to inform water resources management and planning in the Murray–Darling Basin.
MD-WERP
Science and research

 

MD-WERP theme Hydrology
MD-WERP research question How can low flow prediction be improved to support water resources management planning?
Project title Enhancing low flow prediction to support water resources planning
Research lead CSIRO
Authors Russell Crosbie, Jai Vaze, Shaun Kim, Cherry Mateo and Bill Wang
Author contact details Russell Crosbie
Date of publication June 2022
Report full title Summary of datasets for classification of river reaches in the Murray–Darling Basin and changes in the flow regime over the past few decades
Keywords Murray–Darling Basin; northern Basin; southern Basin; low flows; river system models; predictions; hydrological; river reaches; streams; river system models;
Summary of output
  • These datasets are to be used as contextual information for understanding why our rivers system models have poor predictive performance for low flows. The models have no information on the status of the groundwater conditions for the reach, or a memory of the antecedent conditions within the channel.
  • This may not be a problem when the conditions under which predictions are made are the same as those under which the model was calibrated but may become a problem if the hydrological regime is changing beyond the conditions experienced during calibration.
  • Further analysis of these datasets will guide the modifications necessary to existing model structures to provide better predictions of future low flows. 
Key findings / recommendations
  • The results show that there has been a considerable increase in the proportion of intermittent streams in the Basin over recent decades, particularly in the northern Basin.
  • Over the past 20 years, most of the river reaches in the northern basin are mostly or always losing. In the southern basin, many reaches have an increasing trend in the proportion of bores predicting losing conditions.
  • The analysis of changes in flow regime over the past few decades indicate that the flow regime is not static in time. Both the decreasing perenniality of flow and increasing losing conditions will lead to less reliable low flows that cannot be explained by flow regulation alone.
  • These analyses demonstrate the hydrological processes missing from the current generation of river system models that will need to be incorporated to allow better prediction of low flows into the future.
Target audience Water managers, river managers, catchment managers, researchers, hydrological modellers, Australian Government, state governments, local governments, community

Published date: 19 May 2025