|Despite considerable expenditure of public and private funds on salinity (the Victorian Auditor General estimated at $1.8 billion over the period 1990-2001) we still do not have a reliable measure of the outcome of our salinity management program. The location, size and intensity of soil salinity has been accepted as a significant environmental indicator at Federal level and would also provide a valuable tool for reporting against Victorian Government Outcomes such as Matters for Targets, GVT, the ESF and DSE outcomes. Current field based methods are considered to be too expensive and labour intensive to implement at a state wide level.|
Airborne and satellite based multi-spectral sensors have been advocated as technologies for reducing the cost of field based measurement of soil salinity. However, they are limited spectrally and spatially (Landsat 7 for example has 6 bands in the visible to mid-infrared region ranging from 60 to 250 nm wide with 30 metre pixels), and it is unlikely that such data will ever successfully map vegetation down to a genera or species level. Instead, methodologies using multi-spectral data tend to rely on surrogate indicators of soil salinity such as mapping areas of consistently poor growth. This approach works well in some environments, but is likely to be limited in moderately and slightly saline areas where salt tolerant species can still thrive and maintain good ground cover.