All polygons visually checked at 1:100,000 scale and by topological consistency checks. Inconsistencies between the water body classification and wetland regional ecosystem classification were highlighted, manually checked and reconciled.
Absolute External Positional Accuracy
The positional accuracy of wetland data mapped at a scale of 1:100 000 is +/-75 metres. The minimum polygon size depicted is 5 ha or 75 metres wide for linear features, except for areas along the east coast which are mapped at the 1:50 000 scale with a positional accuracy of +/-50 metres, with a minimum polygon size of 1 ha or 35 metres wide for linear features. Wetlands smaller than 1 ha are not delineated on the wetland data. NB: Consideration of the effects of mapped scale is necessary when interpreting data at a larger scale, (eg: 1:25,000).For property assessment, digital linework should be used as a guide only.For further details refer to Attachment 3 Scale of Final Wetlands Mapping located on the DSITIA website.
Non Quantitative Attribute Accuracy
Regional EcosystemsFormal and informal assessments show regional ecosystem attributes to be accurate > 80% of the time.Water BodiesFormal assessment of selected areas (EPA, 2005) has shown that the delineation of wetlands by the water body mapping to have an overall accuracy of between 93-98%. The producer's accuracy of non-wetlands (i.e. how accurately non-wetland areas are mapped and the user's accuracy for wetlands (i.e. how accurate areas mapped as wetland are wetland) is also consistently high ranging from 77-99%. The water body mapping does miss substantial areas of wetland, as the producer's accuracy for wetlands is relatively low ranging from 14-54%. However, as the wetland regional ecosystem data maps areas of wetlands that are not well mapped by the water body data, many of these areas are not missing from the wetlands data.
Lineage statement, a general explanation
Queensland Wetland Data Version 3.0 - Wetland Data (2009), is an updated version of data previously released as version 1.0 (GBR catchments), version 1.1 (Wide Bay Burnett catchments), version 1.2 (Great Barrier Reef, northern Cape York Peninsula and Queensland Murray Darling Basin), version 1.3 (Queensland, 2001 extent) and version 2.0 (Queensland, 2005 extent) , versions up to and including version 1.3 depicted extent of wetlands based on rectified 2001 Landsat ETM+ imagery, version 2.0 depicted extent of wetlands based on rectified 2005 Landsat ETM+ imagery . Version 3.0 updates the depiction of the extent of wetlands from 2005 to 2009 based on rectified 2009 Landsat ETM+ imagery.This data is produced by combining (by union) the wetland regional ecosystem areas with water body data. Where overlap occurred across water bodies and regional ecosystem polygons, water body polygons take priority over regional ecosystem polygons, except for areas within mangrove and salt flat regional ecosystems. The identification of individual water bodies is not useful within these regional ecosystems, due to the limitations associated with mapping water bodies from satellite imagery in tidal areas.