Contacts

Identifiers and Keywords

ANZLIC Id

ANZVI0803004017 

Victorian Spatial Data Library (VSDL) Schema

MARINE1:BATHYMETRY_BASS_STRAIT_POLY 

Jurisdiction

Victoria 

Topic category

• Oceans

Resource Constraints

Use limitation

http://www.data.vic.gov.au/ The bathymetric information contained within this layer is not to be used for navigation purposes 

Classification

Unclassified  

Creative Commons Attribution 4.0 (CC-BY)

• 
• License Text

Other Dataset Details

Date ( Revision )

2014-11-13

Date ( Publication )

2018-01-23T12:34:47

Status

Completed  

Purpose

BATHYMETRY_BASS_STRAIT_POLY is a 1:250,000 polygon layer which represents subtidal relief (bathymetry). This layer will serve as a Digital Terrain Model (DTM) until more depth data can be obtained from which DTMs can be generated using automated techniques. Common uses for depth zone information include comparative analysis with fisheries catch data and representing the movement of commercial species in three dimensions. The depth information contained within this layer should not be used for navigation purposes. Vertical datum is mean sea level. The 10 metre contour and 0-10 m depth zone were interpolated by DPI Queenscliff (formerly MAFRI) using the coastline and the 20 metre contour. 

Credit

Ralph Roob, Allister Coots 

Supplemental Information

History: This layer replaced DEPTH250_POLYGON in March 2010 Relationship to other Datasets: The depth zones are bounded by isobaths from the BATHYMETRY_BASS_STRAIT_ARC layer.The landward boundary is the 1:250,000 coastal trace. The coastal trace is subject to change especially in areas subject to erosion or mass movement of coastal sediments. In order to create polygon depth zones, the isobaths used in this layer are a reduced set from those found in the BATHYMETRY_BASS_STRAIT_ARC layer. Not all of the isobaths in BATHYMETRY_BASS_STRAIT_ARC are complete for the entire area covered by this layer and some of the isobaths on the edge of the continental shelf are too closely spaced to practically create polygons. As a result the depth zones found in this layer cover depth ranges of between 10, 20 or 50 m depending on the gradient of the seabed and the available data. This layer does not include depths for bays and inlets with the exception of coarse scale contours for Port Phillip Bay. Depth information is available in separate 1:25,000 layers for the main bays and inlets in Victoria. Current Design Issues: All bathymetric information is collected as point features or spot depths. Isobaths are interpreted either by visual manual methods or by automated techniques. As more data becomes available the positional accuracy of isobaths should be revised. Each acquisition of depth information needs to be documented and assessed before it is incorporated in the layer. Future Design Issues: This layer is a baseline data set and future design considerations will be limited. Related Documents: None 

Maintenance and update frequency

As needed  

Maintenance date ( Publication )

2018-01-23T12:34:47

Spatial

Spatial representation type

Vector  

Reference system identifier

4283

Temporal

Begin date

1995-02-01 

End date

1995-03-31 

Resolution

Horizontal Accuracy

250m  

Quality

Conceptual Consistency

This layer exists as a single entity for Bass Strait. 

Missing Data

Bass Strait This layer is complete for Bass Strait. 

Attribute Quality

There has been no assessment of attribute accuracy. 

Positional Accuracy

Precision of source data (1:250,000 Natioinal Bathymetric Map Series): Horizontal accuracy 100m to 1km of well defined points. Vertical accuracy 10cm to 1m in elevation. Depths are relative to Mean Sea Level. Digital precision: Any departure between the digital and source material (measured between centre lines) will not exceed 1mm at map scale (i.e. 250m at 1:250,000) Determination: Positional accuracy is only an estimate and has not been subject to any test. The depth information within this layer should not be used for navigation purposes. 

Lineage

Description

The data was generated from the 1:250,000 National Bathymetric Map Series. Polygons were generated by adding breaklines to close off isobaths and deleting isobaths of 10 metre intervals not represented in their entirety because of close spacing, especially on the continental shelf, leaving the isobaths of 50 metre intervals to represent the depth ranges. Polygon topology was built and then attributed according to the shallowest and deepest isobath forming the boundary of the depth zone. The area between the 20 metre contour and the coastline is generally unsurveyed and the source maps did not have a 10 m contour. As a result the 10 m contour and 0-10 m depth zone in this layer were created by DPI Queenscliff (formerly MAFRI) by interpolating a line between the coastline and the 20 m contour. 

Statement

Dataset Source: Division of National Mapping - 1:250,000 National Bathymetric Map Series (1977-1986) Dataset Originality: Derived 

Attributes

Column Name	Obligation	Unique	Data Type	Data Length	Data Precision	Data Scale	Reference Table Owner	Reference Table Name	Reference Table Code Column Name	Short Column Name	Definition
AREASQM	O	N	NUMBER	22	12	0				AREASQM
DEPTHRANGE	O	N	VARCHAR2	20						DEPTHRANGE
DEPTHP2501	O	N	NUMBER	22	11	0				DEPTHP2501
DEPTHS	O	N	NUMBER	22	6	0				DEPTHS
DEPTHP250_	O	N	NUMBER	22	11	0				DEPTHP250_
MAXDEPTH	O	N	NUMBER	22	3	0				MAXDEPTH
VERSION	O	N	NUMBER	22	3	0				VERSION
PERIM_M	O	N	NUMBER	22	6	0				PERIM_M
MINDEPTH	O	N	NUMBER	22	3	0				MINDEPTH

About the Metadata Record

Metadata identifier

urn:uuid / f4173d98-ef98-5690-b9d5-70808fcc3403