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Geomorphic units of Australia's EEZNote: This metadata describes the dataset in accordance with the ANZLIC (Australia New Zealand Land Information Council) Core Metadata Guidelines Version 2. Dataset citationANZLIC unique identifier: ANZCW0703008890 Title: Geomorphic units of Australia's EEZ CustodianCustodian: Geoscience Australia Jurisdiction: Australia DescriptionAbstract: The dataset provides outlines for the maximum extent of Geomorphic Units of Australia's Exclusive Economic Zone, including the offshore island territories but not the Australian Antarctic Territory. The 14 Geomorphic Unit classes represent areas of similar geomorphology across Australia's EEZ and are intended to capture some of the small-scale benthic marine habitat distributions. They were derived from a quantitative analysis of individual geomorphic features on the Australian margin. The data were compiled in 2004 as part of the draft benthic marine bioregionalisation which is designed to provide improved knowledge of Australia's seabed. The dataset includes the names of units in the attribute table as well as the area and perimeter of each class. ANZLIC search words:
Spatial domain:
Geographic extent name: AUSTRALIA INCLUDING EXTERNAL TERRITORIES - AUSAAT - Australia - Australia Geographic extent polygon: 90 -9, 175 -9, 175 -55, 90 -55, 90 -9, Note: The format for each Geographic extent name is: Name - Identifier - Category - Jurisdiction (as appropriate) See GEN Register
Data currencyBeginning date: 2002-07-01 Ending date: Not Known Dataset statusProgress: In Progress Maintenance and update frequency: Not Known Access
Access constraints: No restrictions Free Data DownloadData qualityLineage: The Geomorphic Units were defined from a spatial analysis of the geomorphic feature dataset as part of the development of the draft national benthic marine bioregionalisation run by Geoscience Australia and National Oceans Office to create a spatial inventory of large-scale benthic biogeographical regions for Australia?s Exclusive Economic Zone. The objective of the analysis was to define areas of like geomorphology across Australia?s EEZ to highlight regions of similar benthic marine biodiversity at spatial scales relevant for marine planning. A quantitative analysis of individual geomorphic features (e.g., plateau, sill, terrace) was first undertaken to objectively describe the spatial distribution of seabed geomorphology. Two simple spatial metrics were used to undertake this spatial clustering: Cohesion, which is a measure of the physical connectedness of individual features (i.e., a shape measure); and Connectance, which is a measure of the total number of physical joinings between individual patches subject to a 1,000 km threshold distance. The Geomorphic Units were generated using a Joining Tree algorithm, with Complete Linkage and Euclidean Distance options on the Cohesion and Connectance metrics. The final classifications were decided by visual inspection of the joining tree to produce meaningful classes. The results of this spatial analysis were also used to guide a subjective clustering based on the presence and absence and relative spacing of smaller and more numerous geomorphic features on the shelf and slope. Positional accuracy: Positional accuracy of the boundaries varies depending on the source data. Due to the scale of the map, and quality of the bathymetric, reflectionand sediment data, the approximate accuracy of the boundaries is probably +/-10 km. Attribute accuracy: No attribute for data quality exists at this stage. This attribute will be updated once a reliability map for the source data has been generated. The reliability map will be based on the spatial distribution of soundings. Logical Consistency: The Geomorphic Units were derived from individual geomorphic features which themselves were derived from Geoscience Australia?s 250 m bathymetry grid. The bathymetric grid was examined visually for data consistency. In some circumstances individual data were inconsistent in the grid. In these cases the data were either left out or corrected. Where appropriate, the boundaries and Primary Bathymetric Unit classifications are consistent with United Nations Law of the Sea boundaries and definitions. Tests were also carried out on the data for completeness, correct spatial representation, attribute accuracy, and logical consistency and correctness Completeness: Coverage: The Geomorphic Units cover all of the Exclusive Economic Zone. The raw data that makes up the bathymetric grid upon which the units are based is derived from numerous sources and has been obtained opportunistically hence the actual data coverage is generally patchy and irregular. A data density map for the bathymetry grid is not yet available. Classification: The final Geomorphic Units represent unique groups of individual geomorphic features which are internationally recognised categories of seabed features (IHO, 2002). Further details of these terms and documentation underlying their adoption by IHO may be found at the following internet address: http://www.iho.shom.fr/publicat/free/files/B6efEd3/pdf. Verification: Field verification was limited to reviewing published literature of the individual geomorphic features and their combinations which make up the Geomorphic Units. Contact information
Metadata informationMetadata date: 2013-03-08 Additional metadataMetadata reference XHTML: http://www.ga.gov.au/meta/ANZCW0703008890.html Metadata reference XML: http://www.ga.gov.au/meta/ANZCW0703008890.xml Nominal Scale 1 : 5000000 REFERENCE: IHO, 2002. http://www.iho.shom.fr/publicat/free/files/B6efEd3/pdf. CONTACT POSITION: Petroleum and Marine Division Project Data Officer Authors:Heap, A.D. Harris, P.T. Hinde, A. Woods, M. |
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