Data provided are the scale of polygonal datasources used to generate the
polygon derived surfaces for the intensive agricultural areas of Australia.
Data modelled from area based observations made by State soil agencies.The
final ASRIS polygon attributed surfaces are a mosaic of all of the data
obtained from various state and federal agencies. The surfaces have been
constructed with the best available soil survey information available at the
time. The surfaces also rely on a number of assumptions. One being that an
area weighted mean is a good estimate of the soil attributes for that polygon
or mapunit. Another assumption made is that the lookup tables provided by
McKenzie et al. (2000), state and territories accurately depict the soil
attribute values for each soil type.The accuracy of the maps is most dependent
on the scale of the original polygon data sets and the level of soil survey
that has taken place in each state. The scale of the various soil maps used in
deriving this map is available by accessing darasource grid, the scale is used
as an assessment of the likely accuracy of the modelling.The Atlas of
Australian Soils is considered to be the least accurate dataset and has
therefore only been used where there is no state based data.Of the state
datasets Western Australian sub-systems, South Australian land systems and NSW
soil landscapes and reconnaissance mapping would be the most reliable based on
scale. NSW soil landscapes and reconnaissance mapping however, may be less
accurate than South Australia and Western Australia as only one dominant soil
type per polygon was used in the estimation of attributes, compared to several
soil types per polygon or mapunit in South Australia and Western Australia.
NSW soil landscapes and reconnaissance mapping as the name suggests is
reconnaissance level only with no laboratory data. The digital map data is
provided in geographical coordinates based on the World Geodetic System 1984
(WGS84) datum.
See [further metadat](http://data.daff.gov.au/anrdl/metadata_files/pa_dams_r9cl_
_04011a00.xml) for more detail.