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Catchment Polygons, National Geochemical Survey of Australia, 2011

This dataset was created for the National Geochemical Survey of Australia (NGSA) to help determine the location of target sites for sampling catchment outlet sediments in the lower reach of defined river catchments. Each polygon represents a surface drainage catchment derived from a national scale 9 second (approximately 250 m) resolution digital elevation model. Catchments were extracted from an unpublished, interim version of a nested catchment framework with an optimal catchment area of 5000 km2. Only catchments from the Australian mainland and Tasmania were included. In order to generate catchments approaching the optimal area, catchments with an area of less than 1000 km2 were excluded from the dataset, while other small catchments were amalgamated, and catchments much larger than 5000 km2 were split.

Simple

Identification info

Date (Publication)
2011-01-01T00:00:00
Date (Revision)
2019-04-08T05:58:49
Citation identifier
Geoscience Australia Persistent Identifier/https://pid.geoscience.gov.au/dataset/ga/73085

Cited responsible party
Role Organisation / Individual Name Details
Author

McPherson, A.A.

1
Author

Cooper, M.

2
Author

Stein, J.L.

3
Author

Hutchinson, M.F.

4
Author

Lech, M.E.

5
Author

de Caritat, P.

6
Point of contact
Role Organisation / Individual Name Details
Custodian

MNHD

Owner

Commonwealth of Australia (Geoscience Australia)

Custodian

Commonwealth of Australia (Geoscience Australia)

Voice
Topic category
  • Geoscientific information

Extent

N
S
E
W


Maintenance and update frequency
As needed
Keywords
  • GIS Dataset

  • National

Theme
  • geochemistry

Theme
  • hydrology

Theme
  • soils

Theme
  • GIS

Keywords
  • AU

Australian and New Zealand Standard Research Classification (ANZSRC)
  • Earth Sciences

Keywords
  • Published_External

Resource constraints

Title

Creative Commons Attribution 4.0 International Licence

Alternate title

CC-BY

Edition

4.0

Website

http://creativecommons.org/licenses/

Access constraints
License
Use constraints
License

Resource constraints

Title

Australian Government Security ClassificationSystem

Edition date
2018-11-01T00:00:00
Website

https://www.protectivesecurity.gov.au/Pages/default.aspx

Classification
Unclassified
Language
English
Character encoding
UTF8

Distribution Information

Distributor contact
Role Organisation / Individual Name Details
Distributor

Commonwealth of Australia (Geoscience Australia)

Voice
OnLine resource

File download

Download the file (pGDB)

OnLine resource

File download

Download the file (shp)

OnLine resource

File download

Download the file (tab)

Resource lineage

Statement

The Centre for Resource and Environmental Studies (CRES - now the Fenner School of Environment and Society) at the Australian National University extracted catchments with an average area of approx. 5000 km2 from an unpublished, interim version of a nested catchment framework (Stein, 2006). Main stem sub-catchment units less than 2500 km2 in area were combined with the upstream tributary catchment, and closed (internally draining) basins of combined area less than 10,000 km2 were iteratively aggregated with a lower neighbouring catchment via the lowest point on the drainage divide. The catchments were derived using a multi-flow extension of an early version of the GEODATA 9 second Flow Direction Grid (ANZLIC unique identifier: ANZCW0703012015) associated with the GEODATA 9 second Digital Elevation Model (DEM) Version 3 (Hutchinson et al. 2008; ANZLIC unique identifier: AW0703011541).

Geoscience Australia then used ESRI ArcGIS® software (v.9.1) (ESRI, 2007) and ArcHydro® Tools (v.1.2 beta) (Maidment and Djokic, 2000) to generate a higher resolution catchment coverage of Australia (threshold area 500 km2) from the 9 second DEM. This high-resolution coverage was used to guide the disaggregation of over-sized polygons in the CRES coarse-scale catchment coverage and bring them within an optimal area range of 4000-6000 km2. Catchment polygons with areas less than this range were, where appropriate, aggregated with neighbouring polygons to again achieve an optimal area. Decisions on which polygons to aggregate or disaggregate were guided by information obtained from these datasets:

- NATMAP Raster Premium 2005 (includes 1:250,000 scale topographic and cultural information for the whole of Australia), along with a Landsat 7 national mosaic (Geoscience Australia, 2007);

- Shuttle Radar Topography Mission (SRTM) 3 second (~90 m) v.2 digital elevation model (NASA, 2007).

Applying the method outlined above, an iterative series of edit, clean and build processes in ArcINFO® resulted in the final national catchment coverage. ArcHydro® Tools (v.1.2 beta) was then used to generate an outlet point for each catchment. These points were used as target sites for field sampling of catchment outlet sediments. Point location adjustments were made manually, if necessary, following consultation with State/Territory Geological Surveys and/or assessment against other environmental datasets. Adjustments were made to account for factors such as proximity to sources of contamination, inaccessibility, or false outlet point placement (e.g. points on the Gulf of Carpentaria which were auto-generated in tidal mangrove swamps).

Subsequent to field sampling, minor adjustments to a small number of catchment boundaries were made manually using ArcGIS® software. These adjustments related primarily to catchments where samples had been collected just outside their designated catchment bounds, and generally involved extending the boundary closest to the catchment outlet downstream, usually resulting in a net change to the affected catchment areas of <100 km2.


Notes:

References are listed under Additional Metadata.

The current nested catchment framework is distributed by the Bureau of Meteorology as the 'Geofabric': http://www.bom.gov.au/water/geofabric/index.shtml (last accessed 9 Nov 2011)

Further information on the methods used to generate the NGSA catchments and target sampling sites can be found in Lech, M.E., Caritat, P. de, McPherson, A.A. 2007. National Geochemical Survey of Australia: Field Manual. Geoscience Australia, Record 2007/09, 53 pp.

Hierarchy level
Dataset
Description

Source data not available.

Metadata constraints

Title

Australian Government Security ClassificationSystem

Edition date
2018-11-01T00:00:00
Website

https://www.protectivesecurity.gov.au/Pages/default.aspx

Classification
Unclassified

Metadata

Metadata identifier
urn:uuid/b1d20bbb-cab7-6e7d-e044-00144fdd4fa6

Title

GeoNetwork UUID

Language
English
Character encoding
UTF8
Contact
Role Organisation / Individual Name Details
Point of contact

Commonwealth of Australia (Geoscience Australia)

Voice

Type of resource

Resource scope
Dataset
Name

dataset

Alternative metadata reference

Title

Geoscience Australia - short identifier for metadata record with

uuid

Citation identifier
eCatId/73085

Metadata linkage

https://ecat.ga.gov.au/geonetwork/srv/eng/catalog.search#/metadata/b1d20bbb-cab7-6e7d-e044-00144fdd4fa6

Date info (Revision)
2018-04-22T08:45:13
Date info (Creation)
2011-11-16T00:00:00

Metadata standard

Title

AU/NZS ISO 19115-1:2014

Metadata standard

Title

ISO 19115-1:2014

Metadata standard

Title

ISO 19115-3

Title

Geoscience Australia Community Metadata Profile of ISO 19115-1:2014

Edition

Version 2.0, September 2018

Citation identifier
https://pid.geoscience.gov.au/dataset/ga/122551

 
 

Spatial extent

N
S
E
W


Keywords

GIS geochemistry hydrology soils

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