Mass Movement (landslip)

Dataset Number1047
Dataset TitleMass Movement (landslip)
CustodianData Authority: Department for Environment and Water
Data Provider: Department for Environment and Water

Description

DescriptionMass 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.
UsageLink 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

LineageThe 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.
CompletenessComplete. The spatial data is subject to amendment as and when more data become available.
Positional AccuracyThe 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 NameAgricultural Region - South Australia
Min Easting or Longitude132.25
Min Northing or Latitude-38
Max Easting or Longitude141
Max Northing or Latitude-32.25

Dataset Status

Initially Acquired01-JAN-2000
Last Updated01-JUL-2009
Update FrequencyAs required
Maintenance MethodAs required
LicenseingCC BY (Attribution)

Attributes

TableNameField AliasData TypeDescription
Landscape.SALAD_Erosion_MassMovementLANSLU CharacterSoil Landscape Map Unit.
Landscape.SALAD_Erosion_MassMovementEROS_MASS CharacterExtent of (or potential for) landslip (Legend category. See layer file for descriptions).
Landscape.SALAD_Erosion_MassMovementL1 NumberPercentage of map unit not affected (and negligible potential) by mass movement.
Landscape.SALAD_Erosion_MassMovementL2 NumberPercentage of map unit not affected but with potential for mass movement.
Landscape.SALAD_Erosion_MassMovementL3 NumberPercentage of map unit affected by mass movement.
Landscape.SALAD_Erosion_MassMovementLX NumberPercentage of map unit which is not applicable.

Contact Information

OrganisationDepartment for Environment and Water
Science Monitoring and Knowledge
Postal AddressGPO Box 1047

ADELAIDE
5001
EmailDEWNR.CustomerServiceCentre@sa.gov.au