Dataset: Victorian Coastal Acid Sulphate Soils



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

Spatial data representing Victorian coastal lands which have the potential to contain coastal acid sulfate soil (CASS), i.e. it is prospective for CASS. This spatial data is used for triggering an investigation of a site where proposed activities risk disturbing CASS. Disturbing CASS is defined as causing oxygen to penetrate earth material that contains metal oxides either in sulfidic material or sulfuric material. Sulfidic material is soil or sediment that contains metal sulfides which oxidise to sulfuric acid in the presence of oxygen. Sulfuric material has either partially or completely oxidised metal oxides. This data was created to help avoid disturbing potential CASS.

Dataset History

Data Set Source:

Mapping was by interpretation of aerial photography, and data on site features, topography, water quality, soil and geology. Shapefiles were in decimal degrees with a datum of GDA94. LiDAR derived DEM data (MGA94) was used to aid mapping. In some areas, mostly in the eastern half of the state, contour lines from the DEM data, served as critical values of elevation (typically 2, 2.5, 3, 3.5 m AHD) below which prospectivity was interpreted to exist: a model typically applied to coastal plains, dunefields, flood plains and swamps. On-ground survey and soil analytical data was confined to land west of Lake Tyers. All inland boundaries were smoothed (PAEK 50-100 m) for Prospective Land. Made Land and Water were not smoothed and abut Prospective Land without gaps. The Water polygons were from the HY_WATER_AREA_POLYGON_NAMED spatial layer for all but Mallacoota Inlet and Reedy Lake, where the ESTUARIES spatial layer was used. While some waterbodies are navigable, many are shallow, many vary in outline and area with seasons, and some are ephemeral. Shorelines were used to clip the seaward extent. The shoreline boundaries were from the VIC_AUSCSTGEO_SHORELINE_SEG spatial layer for most of the coast. SHORELINE25 spatial layer was used in some parts, e.g. Bass River.

Collection Method:


Processing Steps:


Positional Accuracy: ?30m Handheld GPS

Atribute Accuracy: Derived from sparse field samples

Logical Consistency: Not Known

Dataset Citation

Victorian Department of Environment and Primary Industries (2014) Victorian Coastal Acid Sulphate Soils. Bioregional Assessment Source Dataset. Viewed 29 September 2017,

General Information