Title

Bass Strait Depth Zone Contour Lines at 1:250,000 

Alternate title

BATHYMETRY_BASS_STRAIT_ARC 

Purpose

BATHYMETRY_BASS_STRAIT_ARC is a 1:250,000 line 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 m contour was interpolated by DPI Queenscliff (formerly MAFRI) using the coastline and 20 m contour. 

Credit

Ralph Roob, Allister Coots 

Supplemental Information

History: This layer replaced DEPTH250_ARC in March 2010 Relationship to other Datasets: A subset of these isobaths were used to bound depth zones in the BATHYMETRY_BASS_STRAIT_POLY 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. This layer does not include depths for bays and inlets with the exception of coarse scale contours for Port Phillip. 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 

Status

Completed  

Horizontal Accuracy

250m  

Code

4283 

Maintenance and update frequency

As needed  

Topic category

• Oceans

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  

Statement

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

Description

Collection Method: Digitising of maps from the 1:250,000 National Bathymetric Map Series. 

Description

The data was digitised from the 1:250,000 National Bathymetric Map Series. 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 in this layer was created by MAFRI by interpolating a line between the coastline and the 20 m contour. 

Classification

Unclassified  

Attribute Quality

Comments

There has been no assessment of attribute accuracy. 

Positional Accuracy

Comments

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. 

Conceptual Consistency

Comments

This layer exists as a single entity for Bass Strait. 

Missing Data

Comments

Bass Strait This layer is complete for Bass Strait. 

Excess Data