To improve the scientific basis of national policy development and to enable better resource assessment, monitoring and management, a geographic information system (GIS) has been developed to describe and evaluate the distribution and abundance of grazing livestock populations and their productivity.

Data were processed using the ArcInfo GIS. Livestock distribution was based on statistical local area (SLA) boundaries obtained from the Australian Surveying and Land Information Group (AUSLIG). Distribution within SLAs was then adjusted to exclude land not available for grazing (AUSLIG, 1979). The remaining area was classed as grazing land suitable for livestock production. Further refinements to distribution were made using advice based on knowledge from livestock specialist in State departments.

The average density ( sheep or cattle per hectare) for total grazing land of each SLA was calculated, based on livestock numbers from Agstats (1988-89). Total livestock density was calculated as the average number of livestock equivalents per hectare of total grazing land per SLA. Areas of similar density were grouped for display purposes.