Hydrological research from the University of Melbourne is challenging long-held assumptions about Australia’s water catchments, suggesting they might not be as resilient as first thought.
Dr Tim Peterson and Professor Andrew Western have collaborated with the Bureau of Meteorology and Victorian Government to identify how climate and other factors influence catchment resilience to disturbances such as droughts.
We have traditionally assumed that our catchments are infinitely resilient but our research has shown, at least theoretically, that this is not necessarily the case.Dr Tim Peterson
He says stream flows and groundwater might drop during a drought, but even when the drought ends and rainfall returns, they could remain at low levels until an extreme wet event occurs. Or they may never return to their original state.
The initial project, funded through an Australian Research Council linkage grant, also revealed gaps in understanding about groundwater resources, which the project partners were keen to address.
The Bureau of Meteorology reports on groundwater as part of its National Water Account. Groundwater also became a contentious community issue during the Millennium Drought, with competing interests wanting to access its dwindling supplies to supplement other limited water sources.
Dr Peterson says this led to another linkage grant, which helped to develop the open-access software toolbox HydroSight. The software allows water managers across Australia to evaluate individual groundwater sources and test responses to future scenarios.
Using a statistical approach, HydroSight analyses monitoring data to identify how different aquifers function and what factors contribute to changing water levels over time. It can identify whether a decline in groundwater level is due to climate or to pumping and can predict the likely impacts of changes in groundwater use. It can also evaluate how reforestation or clearing of a site has affected local groundwater levels.
HydroSight allows anyone with access to monitoring data to generate useful information about their groundwater, which means they are able to make better decisions about the management of this valuable resource, Dr Peterson says.
Dr Tim Peterson