NSW Wetlands

Abstract

This dataset and its metadata statement were supplied to the Bioregional Assessment Programme by a third party and are presented here as originally supplied.

The purpose of this project was to map the wetlands across New South Wales. Wetlands were identified using a combination of classification of spectral classes of Landsat MSS and TM imagery and ancillary wetland information to create information classes of broad wetland groups (floodplain wetlands, freshwater lakes, saline lakes, reservoirs, estuarine wetlands and coastal lagoons and lakes). The data will then be used to assess the wetland resource in each catchment.

Dataset History

The wetlands of the inland catchments were identified using unsupervised classification of Landsat MSS imagery on the basis of the presence of water. The wetlands of the coastal catchments were mapped with Landsat TM imagery. Wetlands were identified using a band 5 slice In both instances the thematic grid was vectorised using Arc/Info. Wetland areas were grouped a posteriori using ancillary attribute data such as aerial survey of wetland data, 1:250000 hard copy maps sheets, AUSLIG 250K waterbody theme, existing wetland maps. Each Landsat image scene was geometrically rectified and geocoded to UTM coordinates using topographic maps- 1:250000 scale for the inland catchments and 1:25,000 for the coastal catchments. A Root Mean Square Error of less than one was achieved for each image.Arc/Info was used to do topological consistency checks to detect flaws in the spatial data structure and to identify them as errors. This check ensures that all classified polygons are closed, nodes are formed at the intersection of lines, and that there is only one unique label within each. Multiple and dangling lines were also edited. All polygons were visually checked by draping over Landsat imagery using ERDAS Imagine to ensure that polygons were correctly coded.Both the unsupervised classification and band 5 slice is reliant on imagery being acquired at a wet period (some areas may have been missed because of dry imagery and/or cloud cover). Accuracy assessment was performed on both coastal and inland mapping.

Dataset Citation

"NSW Department of Environment, Climate Change and Water" (2010) NSW Wetlands. Bioregional Assessment Source Dataset. Viewed 13 March 2019, http://data.bioregionalassessments.gov.au/dataset/90476e12-77a2-4970-a0be-942eeb84e95e.