It should be noted that this data is now somwhat dated!
Many industries discharge pollutants into streams a heavy metals, toxins,
nutrients and so on, which affect stream quality. The rate of discharge is
assumed to be proportional to the number of potential discharge points.
This indicator was developed from the Wild Rivers data set (Environment
Australia, 1997) which includes national data on point sources of pollution
(1:250K). This data set can be separated into industrial (mines, quarries,
chemical) point sources and nutrient point sources (abattoirs, dairy,
livestock production, sewage). Point sources were given equal weight.
The density of pollution point sources is not an unequivocal indicator of
heavy metal contamination of waterways, since there is no distinction made
between types and toxicities of pollutants, discharge magnitude and frequency,
environmental safe guards and proximity to stream network. The data set was
uncomplete, and should be improved as part of the National Pollution Inventory
data set. The main concentration of pollution sources is along the eastern
seaboard from the mid-coast of NSW to north of Brisbane. These would be mainly
industrial and mining pollutants. High values are for Maroochy, Qld South
Coast, Tweed, Brunswick, Richmond, Hunter, Macquarie, Tuggerah Lakes, Sydney
Coast-Georges, and Wollongong Coast. Inland from the coast, the Hunter Valley,
Bathurst and Orange areas fall into the poorest category. Other areas include
the area around Perth, a high proportion of Tasmania, the Darwin area and the
catchments inland of Cairns.
Data are available as:
- continental maps at 5km (0.05 deg) cell resolution for the ILZ;
- spatial averages over CRES defined catchments (CRES, 2000) in the ILZ;
- spatial averages over the AWRC river basins in the ILZ.
See further metadata for more detail.
