20-04-2004

Australian Agriculture Minister Warren Truss has welcomed the release of a report that analyses salinity mapping techniques and highlights practical and effective ways of tackling salinity.

Mr Truss said the Review of Salinity Mapping Methods in the Australian Context, which was undertaken jointly by the Academy of Science and the Academy of Technological Science and Engineering, represents a major step forward in understanding and managing salinity.

"Salinity is a major problem in Australia , seriously affecting the sustainability of parts of our agriculture sector and the quality of our water resources ," he said. "Anything we can do to help land holders manage salinity more effectively represents a valuable investment in our future.

"The review examined and described 31 salinity mapping methods in language that everyone can understand and assessed their capabilities. The report suggested that the first step in determining if a catchment is likely to have a problem with salt discharging into local streams is to undertake systematic in-stream sampling of the salt concentrations.

"This sampling will help identify areas that need a more thorough investigation, which can be carried out using airborne electromagnetic techniques (AEM) - the only broadacre mapping technique currently available for the remote sensing of below-the-surface salt loads.

"These findings back the advice I gave last September at the launch of the Billabung Creek salinity report at Henty NSW, and represent a proven approach to broad area mapping of salt stores ."

Mr Truss said one of the major benefits of using AEM is that we can now:

• locate salt concentrations that are below the surface;
• determine whether the salt is likely to be moved by groundwater, and
• establish the risks associated with any subsequent movement of the salt.

"Once this information is available, we can respond in ways that best suit the particular locality," he said. "That may include strategies as practical as switching from annual to perennial pastures, localised tree planting and re-siting farm water storages and buildings. In many areas, we can tackle salinity without causing major disruptions to agriculture.

"In higher risk areas, an assessment of existing information, followed by the systematic sampling of salt concentrations in watercourses across the catchment, can help determine which areas need to be mapped.

"The Bureau of Rural Sciences recently used AEM , together with stream sampling and groundwater investigations, at nine localities across the Murray Darling Basin . The results showed that salt is localised, generally stored in quite well defined subsurface locations, and will only be a significant problem if it is moved by groundwater flows ."

Examples on how this technology has been used are available from: www.brs.gov.au

For further information please contact:

Please contact Land & Water Australia
Email:land&wateraustralia@lwa.gov.au
Phone: 02 6263 6000