Where is there a dryland salinity risk or hazard and how was this determined?
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 watertables less than 2 m 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. A number of techniques to spatially extrapolate these data to infer potential areas at risk were trialled 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. Areas affected are based on groundwater le
