Dataset Number 1047 Dataset Title Mass Movement (landslip) Custodian Data Authority: Department for Environment and Water Data Provider: Department for Environment and Water

Description Description Mass movement occurs on sloping ground where large slabs of the ground surface separate and slide or flow downhill. The phenomenon is possibly the result of loss of binding in the soil mass following clearing of woody vegetation, but is generally triggered by excessive wetness in the soil causing simultaneous loss of strength and increased mass. The potential for mass movement, based on existing occurrences, is closely linked to underlying geology. The assessment identifies land with potential for mass movement and land which is already affected. Slope is a critical factor influencing mass movement, and virtually any slope steeper than 30% is at risk once cleared. However, some landscapes are more susceptible than others: 1) Soils on unconsolidated and slowly permeable substrate materials. Susceptible soils include deep clays and sand to sandy loam over clay types on slopes as low as 12%. 2) Soils on sodic shales and quartzites. Mass movement of loam over clay soils on these formations is common where slopes exceed 20%. 3) Soils on strongly laminated shaly bedrock. On slopes where rock laminations are parallel to the ground surface, lubrication of these planes by water can cause slippage of the overlying soil. Four Mass Movement (landslip) analysis data classes (including not applicable) have been supplied, as percentage values of Soil Landscape Map Units to be used for the calculation of spatial data statistics. Note: the sum of all percentage values for each map unit totals 100%. Soil Landscape Map Units are categorised INTO five (plus not applicable) legend categories (EROS_MASS) depending on the proportion of map unit with extent of/or potential for mass movement. Usage Link to Soil Attribute Descriptions. This dataset has been derived from the Soil Landscape Map Units spatial dataset to be used for map creation or the calculation of spatial data statistics. Used to supply Government, community groups, industry and the general public with up to date regional, subregional and catchment level land and soil attribute information for southern South Australia. The aim is to produce maps, statistics and reports displaying and describing: Land and soil attributes within southern South AustraliaSELECT 1 FROM DUAL; Land surface features affecting land use, land management and productivitySELECT 1 FROM DUAL; Limitations / suitability of land and soil for a range of agricultural and other uses. Independent professional advice should be sought before using this in commercial decisions. Further information: soil and land attributes. Mass Movement (landslip) dataset can be viewed at NatureMaps (>Soils>Soil Erosion Attributes). Spatial data downloads are available from Data SA.

Data Quality Lineage The dataset is based on an interpretation of 1:40,000 stereo colour aerial photography and limited field inspection of landscapes and soils by soil scientists. Soil Landscape Map Unit boundaries were determined after an integration of field observations and recordingsSELECT 1 FROM DUAL; laboratory analysesSELECT 1 FROM DUAL; stereoscopic examination of aerial photographsSELECT 1 FROM DUAL; understanding of regional landscape processes and stratigraphySELECT 1 FROM DUAL; existing soil and geological mapping data. To avoid inconsistencies and confusion, any updates to the Soil and Land Attribute mapping are to be managed by DEWNR Soil and Land Program. This data has been released under a Creative Commons licence. Where products are derived from this data, DEWNR are to be acknowledged, and any changes to the original data should be indicated. Completeness Complete. The spatial data is subject to amendment as and when more data become available. Positional Accuracy The accuracy is to the scale of mapping (50 metres at 1:50,000 and 300 metres at 1:100,000 mapping scale). The spatial data is to be used at the regional, subregional and catchment level, and can be used to provide property overviewsSELECT 1 FROM DUAL; however, cannot be used at the paddock level. South East, Kangaroo Island, Mount Lofty Ranges and the 'bottom' of Yorke Peninsula have been mapped at 1:50,000. Eyre Peninsula, the main part of Yorke Peninsula, Murray Mallee and Northern Agricultural Districts have been mapped at 1:100,000. Map unit boundaries should be treated as transition zones.

Geographic Extent Extent Name Agricultural Region - South Australia Min Easting or Longitude 132.25 Min Northing or Latitude -38 Max Easting or Longitude 141 Max Northing or Latitude -32.25

Dataset Status Initially Acquired 01-JAN-2000 Last Updated 01-JUL-2009 Update Frequency As required Maintenance Method As required AusGOAL CC BY (Attribution)

Attributes

Contact Information Organisation Department for Environment and Water Science Monitoring and Knowledge Postal Address GPO Box 1047 ADELAIDE 5001 Email DEWNR.CustomerServiceCentre@sa.gov.au