Example map of salinity and salinity hazard. Orange areas were salt-affected in 1988, red areas became salt-affected by 1998 and blue areas are at risk.

Land Monitor: mapping soil salinity for better land management

CSIRO scientists have developed a technique using satellite maps to estimate the present and future extent of salinity in south Western Australia.

• 18 March 2010 | Updated 14 October 2011

• Overview 
• Project summary 
• Project outcomes

Overview

Salinity is a major conservation and natural resource management challenge and despite drought in many areas possibly removing attention from the issues, the threats to agricultural landscapes and aquatic ecosystems remain.

In Western Australia (WA) salinity has been a high priority environmental issue for many years.

South-west WA is home to important agricultural areas including the wheat belt and the Margaret River wine region, both at risk from increasing levels of salinity due to rising saline ground water as a result of the clearing of perennial vegetation.

CSIRO has created salinity maps using satellite images and digital elevation models (DEMs) to provide information about past and present vegetation cover and land condition.

When these images are combined with information about the terrain and the movement of water through the landscape, it is possible to predict which areas are at risk from salinity.

'Prior to this research the historical extent of salinity just simply wasn't known', said Dr Peter Caccetta, statistician and project leader.

'This work has allowed farmers and regional managers to understand the extent and scale of the problem and this aids in their plans for remedial actions '

In 2004 Dr Peter Caccetta's team was awarded the CSIRO Chairman's Medal. This video talks more about the team and their work mapping salinity and vegetation change in Australia.

Project summary

CSIRO has been progressively developing this spatial mapping technique for salinity since 1987. 

The Land Monitor project was set up by the National Dryland Salinity Program and funded by the WA Department of Agriculture and Food, Land and Water Australia and the National Heritage Trust.

The research has generated large and detailed maps which are distributed to partners and the land holders and general public through a project called Land Monitor.

Results have been used by government agencies to improve investment in agriculture, roads, water and biodiversity management. State programs have also taken this information to farmers, leading to improvements in catchment management

The team also creates maps showing the history of vegetation change, and its current extent in the landscape of the south-west WA agricultural area.

Project outcomes

The management of WA's dryland salinity problem requires reliable information in an accessible format for land holders and government agencies.

The salinity and vegetation maps developed by CSIRO will provide a benchmark for continued monitoring and a method by which future changes can be predicted.

The Land Monitor project continues to:

• systematically monitor and predict salt-affected land
• annually monitor the condition of both remnant and revegetated areas, over an 18 million hectare area in south-west Western Australia — this is roughly half the size of Germany
• ensure that an operational structure is in place to allow regular up-dating on a cost recovery basis
• allow timely, accurate information to be used for environmental auditing purposes as required by a range of State and national imperatives such as the WA and Australian State of Environment Reports and the National Land and Water audits.

The outcomes of the work are being used in national environmental reporting systems and for policy development for vegetation and land management.

The research has led to work with the Australian Government Department of Climate Change (DCC), creating maps showing how vegetation cover has changed in Australia over the last 30 years.

The maps are used as a key foundation for Australia's National Carbon Accounting System (NCAS), which was awarded a Eureka Prize for Environmental Research in 2008. The project team also works in close collaboration with DCC to implement the National Land Cover Changes Program.

Information about forest size, clearing and regrowth from these satellite maps also forms part of the international assessment of Australian's carbon budget.

Read more about the work of the Sustainable Agriculture Flagship