About the Victorian Water and Climate Initiative
We're working on the Victorian Water and Climate Initiative (VicWaCI) with the CSIRO and the Victorian Department of Energy, Environment and Climate Action.
The initiative aims to further analyse the relationship between drivers of Victoria's climate and water resources.
It's now in its second phase (2021–2024). This builds on earlier collaborations:
- South Eastern Australian Climate Initiative (2005–2012)
- Victorian Climate Initiative (2013–2017)
- VicWaCI Phase 1 (2017–2020).
VicWaCI findings inform the guidelines for assessing the impact of climate change on water availability. These guidelines are published on the Department of Energy, Environment and Climate Action website.
Key findings
Over the past few decades, Victoria has experienced its warmest period on record and declining cool-season (April–October) rainfall.
This decline is associated with more high-pressure systems over southern Australia and less rainfall from fronts and low-pressure systems.
Most global climate models indicate that climate change has contributed to the rainfall decline.
While rainfall will continue to vary, with some years being unusually wet or dry, the overall downward trend in cool-season rainfall due to climate change is projected to intensify unless global greenhouse gas emissions fall.
Victoria's cool-season rainfall
Victoria's cool season (May–October) rainfall from 1900–2020 and projections (shown as departures from the 1975–2020 average). Victoria's rainfall is highly variable, but in future the average rainfall will likely be lower.
Extreme rainfall on a sub-daily timescale is increasing, particularly during the warm season. This is despite declining annual-average and cool-season rainfall.
Station sub-daily rainfall extremes have increased in intensity in the north-west and east of Victoria, but remain reasonably steady in the central regions.
Deliverables
Our work aims to understand:
- observed and future trends in Victorian rainfall at a range of timescales
- regime shifts in Victorian rainfall – these are large and persistent changes over several years in annual or seasonal rainfall totals, to wetter or dryer conditions
- Victoria's weather types, how they changed in the past and are projected to change in future
- which compound weather events are most relevant to Victoria's climate and water resources
- how changes in the large-scale circulation in the tropics and to the south of the Australia explain changes in Victoria's climate – for example, El Niño or the polar vortex – and how these processes are represented in climate models
- the impact of rainfall variations on the streamflow and other components of the water balance. This helps understand persistent hydrological droughts. (Learn about types of drought.)