The spatial information on weed infestation was from BRS, downloaded from the ANRDL website. This dataset was compiled using vector weed coverage species from States with 4 classes (present {2}, low {1}, med {2}, high {3}) for Weeds Of National Significance. Thereafter, a relative density rating was derived by multiplying the percentage of the total number of species in each density class by the density weights and summing them. The polygons were then converted to 250 m grid that was resampled to 5 km grid. The data was represented in various ways such as the original 5 km grid, as a spatial average over CRES defined catchment, spatial average over AWRC river basin in the intensive landuse zone. For the present study we used 5 km grid categorised in five categories (BRS, 2001).

The map was downloaded in geographic coordinate system and was project to Albers equal area projection for further analysis. Thereafter, the analysis was calculated for the cropping area (More information- Landuse metadata summary). The area corresponding to different categories of weed infestation was calculated for each GRDC zone (More information- GRDC Zone metadata summary).

Reference- Original metadata

BRS (2001) Indicators of Catchment Condition in the Intensive Land Use Zone of Australia - Weed Density. Bureau of Rural Sciences (BRS), Scale 5 km grid. Source: http://asdd.ga.gov.au/asdd/tech/zap/basic-full.zap?&target=brs-4&syntax=html&cclfield1=all&cclfield2=phrase&cclfield3=any&cclterm1=weed%20density&cclterm2=&cclterm3=&start=1&number=1  (accessed July 2005)

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