Salinity - Non-watertable

Dataset Number1063
Dataset TitleSalinity - Non-watertable
CustodianData Authority: Department for Environment and Water
Data Provider: Department for Environment and Water

Description

DescriptionNon-watertable salinity (also known as 'dry saline land') is land where soils contain elevated levels of soluble salts which are not associated with a watertable. The salts have presumably accumulated in the soil either from aeolian accessions and subsequent leaching, marine aerosols, or via saline groundwaters which are no longer influencing the land surface. Salts generally occur as subsoil 'bulges', which possibly reflect either the extent of leaching (ie salt cannot be leached any further than the depth of the seasonal wetting front), or an impermeable deep subsoil layer which prevents flushing of the salts into substrate materials. Many map units have components of contrasting land types, with variable soil salinity. Six Salinity - Non-watertable attribute (or 'analysis data') classes have been supplied (see 'V1', 'V2' etc in table below, including not applicable) as percentage (areal extent) values of each Soil Landscape Map Unit (SLU). Note: the sum of all percentage values for each map unit totals 100%. This analysis data is to be used for the calculation of spatial data statistics. Classes are based on indicative ECe assessments of the most saline part of the soil (usually the lower subsoil). ECe is electrical conductivity of a saturation paste of water and soil; and values have been estimated from EC(1:5) measurements. Areas of high to extreme non-watertable salinity have traditionally been known as 'magnesia patches', and generally occur as bare patches in otherwise vegetated land. Where salinity impacts are associated with shallow groundwater the separate attribute 'Salinity - Watertable-Induced' should be referred to. This assessment of non-watertable induced salinity estimates salinity levels prior to any watertable influence. For map display purposes, SLUs have been categorised into 5 legend categories (SAL_NWT), including not applicable, to highlight the most severely affected proportion, provided this accounts for at least 30% of the map unit area.
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 Australia; Land surface features affecting land use, land management and productivity; 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. Salinity - Non-watertable dataset can be viewed on NatureMaps (>Soils>Soil Salinity 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 recordings; laboratory analyses; stereoscopic examination of aerial photographs; understanding of regional landscape processes and stratigraphy; 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 overviews; 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
AusGOALCC BY (Attribution)

Attributes

TableNameField AliasData TypeDescription
Landscape.SALAD_Salinity_NonWTableLANSLU CharacterSoil Landscape Map Unit
Landscape.SALAD_Salinity_NonWTableSAL_NWT CharacterSeverity of non-watertable salinity (legend category. See layer file for class descriptions). Map units are categorised according to the most severely affected component, provided this occupies at least 30% of the area.
Landscape.SALAD_Salinity_NonWTableV1 NumberPercentage of map unit with low non-watertable salinity (Indicative ECe - surface: < 2 dS/m; subsoil: < 4 dS/m)
Landscape.SALAD_Salinity_NonWTableV2 NumberPercentage of map unit with moderately low non-watertable salinity (Indicative ECe - surface: 2 - 4 dS/m; subsoil: 4 - 8 dS/m)
Landscape.SALAD_Salinity_NonWTableV3 NumberPercentage of map unit with moderate non-watertable salinity (Indicative ECe - surface: 4 - 8 dS/m; subsoil: 8 - 16 dS/m)
Landscape.SALAD_Salinity_NonWTableV4 NumberPercentage of map unit with moderately high to high non-watertable salinity (Indicative ECe - surface: 8 - 16 dS/m; subsoil: >16 dS/m)
Landscape.SALAD_Salinity_NonWTableV7 NumberPercentage of map unit affected by 'magnesia patches' (>50% bare ground)
Landscape.SALAD_Salinity_NonWTableVX 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