Developing water sharing plans that are comprehensive, rigorous and equitable requires sound scientific and technical knowledge.  With competition for water increasing, it is important to understand patterns of water use and to ask where the opportunities are for water savings, and how can water be ‘best’ distributed to meet a range of needs? Answering these questions requires information about how much water is being used by different land use types at the catchment scale.

Evapotranspiration (ET) is a fundamental component of the catchment water balance, with approximately 90% of total precipitation falling in Australia returning to the atmosphere through ET. Several ground-based methods exist for measuring ET however, they are designed for use at a local scale, and unable to provide estimates at a catchment or planning scale.

A recent study funded by the National Water Commission, has used remote sensed ET data at a number of different regional and local scales to investigate how it can inform water planning and management in Australia.  The results of this work revealed that remote sensing provides estimates of ET that can assist in determining regional water use while also understanding local scale influences. Remote sensing information can be used to assess the amount of water used by different land uses at different times, as well as predicting the effect of likely changes in land use (for example, annual to perennial crops) on water use.

There will be a workshop on this topic at the International Riversymposium where two fact sheets developed by the National Water Commission and the ARRC will be released.  For more see our New Information and Knowledge Page