Title

Gippsland Lakes Depth Contours at 1:25,000 

Alternate title

BATHYMETRY_GIPPSLAND_LAKES_ARC 

Purpose

BATHYMETRY_GIPPSLAND_LAKES_ARC is a 1:25,000 layer used for depth analysis. A specific use for depth zone information include comparative analysis with fisheries catch data and representing the movement of commercial species in three dimensions. The depth information within this layer should not be used for navigation purposes. 

Credit

David Ball and Penny Morris, Department of Primary Industries, Queenscliff 

Supplemental Information

History: This layer replaced GL_BATHYM in March 2010 Current Design Issues: Bathymetric information is initially 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 base line data set and future design considerations will be limited. Related Documents: None 

Status

Completed  

Horizontal Accuracy

100m  

Code

4283 

Maintenance and update frequency

As needed  

Topic category

• Oceans

Use limitation

http://www.data.vic.gov.au/ The depth information contained within this layer should not be used for navigational purposes. 

Classification

Unclassified  

Statement

Dataset Source: Data was digitised from Victorian Channels Authority charts (formerly Ports and Harbours). Two types of data were digitised. Firstly, depth contours that had been manually interpreted and drafted on the charts by Ports and Harbours were digitised as arcs. For the area between Flannagan Island and Lakes Entrance, contours were created automatically in ARCINFO by digitising depth points. The depth charts used to create the layer are listed below. Depth Contours GL166-2752. Lake King scale 1:25,000. Surveyed June 1981-1982: Composite chart derived from 1:10,000 series, Ports and Harbours. Shore detail derived from 1:25,000 series , Lands Department. Contours show depths below A.H.D.. GL165-2751. Lake Victoria scale 1:25,000. Surveyed June 1981-1982: Composite derived from 1:10,000 series, Ports and Harbours. Shore detail derived from 1:25,000 series, Lands Department. Contours show depths below A.H.D.. Depth Points GL159-2596. Flannagan Island to Lakes Entrance. Scale 1:10,000. Surveyed July-Aug, 1981. Soundings are in decimetres. Datum for soundings is 1.313 metres below the P.S.M. plaque in the concrete wall at the base ot the new works jetty and is 0.537 metres below A.H.D. GL158-2590. Tambo Bluff to Flannagan Island. Scale 1:10,000. Surveyed June-Oct, 1981: Soundings are in decimetres. Datum for soundings is A.H.D. which is 1.858 metres below the level of the permanent mark 397, situated at the eastern end of Fort King Road. Dataset Originality: Primary & Derived 

Description

Collection Method: survey vessel, visual interpretation from depth points 

Description

Contours were digitised directly from charts GL166-2752 and GL165-2751. Depth points were digitised from charts GL159-2596 and GL158-2590 then a Tin was created and contoured in ARCINFO. The digitised lines and contoured lines created from the Tin were then appended and the depth contours edited at the point where they overlapped. 

Classification

Unclassified  

Attribute Quality

Comments

All attributes have been checked by DPI Queenscliff 

Positional Accuracy

Comments

Not determined. The depth information within this layer should not be used for navigation purposes. 

Conceptual Consistency

Comments

Not available. 

Missing Data

Comments

Layer has been completed for Gippsland Lakes, not including Lake Wellington which is a relatively shallow waterbody with little variation in depth. 

Excess Data