The data shows areas of dryland salinity risk in 2000 in the Murray-Darling
Basin within NSW and coastal NSW catchments.Areas of risk are based on
groundwater levels and air photo interpretation. The merged data, at a nominal
scale of 1:250 000, show actual areas where dryland salinity or water-tables
less than 2 metres have been measured. For the extent map, every delineated
area is underpinned by either air photo data or by one or more groundwater
bores. Therefore, the area at risk is regarded as conservative due to
limitations in the spatial coverage of air photo and bore data. number of
techniques to spatially extrapolate these data to infer potential areas at
risk were trialed but were considered scientifically or statistically
inadequate. Estimates of impacts are based on areas at risk having groundwater
levels of less than 2 m. An impact assessment based on groundwater less than 5
m and rising was considered inappropriate. Total areas affected with
groundwater less than 5 m and rising have been presented, but only for
improved consistency with other States.
See [further metadata](http://data.daff.gov.au/anrdl/metadata_files/pa_dsa__r1in
__00111a01.xml) for more detail.