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Threats to our Key Assets

The Victorian Mallee is a semi-arid region where potential annual evaporation is up to seven times higher than average annual rainfall.

Regional Context

Salt has been a significant natural part of the Mallee landscape for hundreds of thousands of years, with the surface landscape being separated from a vast store of saline groundwater by a very thin layer of top soils of varying texture.  Therefore, the entire Victorian Mallee ecosystem exists in an extremely fine fresh/salt water balance. Hydrogeological processes play the most important role in affecting this balance.

Key Threats – Salt Impacts 

At a local scale, human activity has the greatest potential to affect hydrogeological processes, typically through land clearing and/or the application of inappropriate and/or excessive irrigation. Historically, our irrigators have irrigated using furrow/flood systems which are inherently inefficient in terms of water use. This has resulted in increases in groundwater recharge resulting in the mobilisation of saline groundwater which has discharged into natural depressions in the landscape including the Murray River and associated wetlands/floodplains. Until recently these impacts could be easily seen by the ring of saline lakes around Sunraysia.

 

Key Threats – Climate Change/variability  

Climate change will present significant challenges to the sustainability of farming practices in the Victorian Mallee irrigated region and the impact these pratices have on the region's natural resource assets. Key predictions include:

  • Increases in the number of days over 35o C from an average of 31o C to over 40o C;

  • More extreme weather events, more often;

  • A decrease in the number of frost events;

  • Reductions of up to 15% in rainfall and in water available to the region from storages;

  • Changes to rainfall patterns.

 

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