TORRES STRAIT ATLAS

Thomas Taranto, Douglas Jacobs, Brian Long

June 1997. REPORT MR-GIS 97/6

Maps

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TORRES STRAIT ATLAS – REPORT MR-GIS 97/6

CONTENTS

Summary

Background

Methods

Results and Discussion

Maps

Summary

Torres Strait is an area of rich geographical, ecological and cultural diversity. Historically, geographical names have been given to locations by various traditional, national and international groups. In many instances, the same geographic locations have been given three or more different names.  This series of annotated basemaps have been collated by the CSIRO Division of Marine Research to minimise conflict, misinterpretation or misunderstandings due to this complex nomenclature.

The atlas consists of a 1:1 million scale keymap and 8 fully annotated basemaps. The names of the graphical entities come from both published and non-published sources. The principle source for the placenames was the Australian Gazette. This was supplemented with  information supplied by the Torres Strait Island Co-ordinating Council (via the MaSTER’s programme) and a comprehensive review of a range of publications.

The Torres Strait Atlas is now the most detailed topographic information  database of the region. The Torres Strait Geographic Information System (TSGIS) has provided the instrument to systematically collate, analyse, verify and cartographically label information from a diverse range of topographic and nomenclature sources. Continental mainland and island areas have been electronically reproduced from the Australian National Topographic 1:100,000 scale series which in turn was constructed from aerial photography and printed with a stated accuracy of approximately 80 meters by the Australian Government. Much of the eastern region, previously uncharted or poorly charted,  has been digitised by CSIRO from satellite imagery at a resolution of 25 meters. The Atlas has a stated accuracy of 150 meters to accommodate variations in the original topographic series.

This series of annotated basemaps will facilitate communication between inhabitants, managers and stakeholders of the region. Though due care has been taken, CSIRO does not warrant that this information is free from errors or omissions.  Feedback from users is both appreciated and necessary to develop the Atlas into a cohesive reference for all. Any errors or omissions should be directed to CSIRO Marine Research, Cleveland GIS Facility.


Background

Managers of the Torres Strait Protected Zone (TSPZ) and researchers providing advice to Torres Strait managers require timely fisheries, environmental and biological information in an integrated, synthesised and easily accessible data-base so that research and management strategies may be determined, applied and continuously reviewed without undue time delays. Such decisions should be based on the most recent and relevant data. For that purpose a comprehensive Geographic Information System (GIS) database of the TSPZ marine resources and critical habitats has been set up for AFMA by CSIRO. The database has been transferred to AFMA as an executive information system (EIS) for use by AFMA and other organisations specified by AFMA (eg BRS, ICC). Maintaining and upgrading the database will be essential as new data from Torres Strait research comes to hand and the results of the research are incorporated into the GIS. Moreover, at present the full power of the off-the-shelf EIS is not being used because personnel with specialist GIS skills and training are required to operate the native system. What is required now is to make the information in the Torres Strait GIS accessible to AFMA managers as and when required without their need for extensive and on-going training.

Torres Strait, situated between Papua New Guinea and Australia, has a rich, complex and diverse marine environment, and many of the traditional and commercial fisheries – Article 22 fisheries in the Torres Strait Treaty – are managed by the Australian Fisheries Management Authority (AFMA). The Authority has recognised the importance of the Treaty and the unique relationship between the Torres Strait Islanders and the sea, shown by the emphasis on fisheries management plans which maximise the opportunities for the traditional inhabitants of both Australia and Papua New Guinea. The sea is as important for cultural traditions and social forms as for their livelihood and future well being (Mulrennan and Hanssen 1994).

Accurate and detailed topographic information of the Torres Strait region  in a format relevant to both traditional inhabitants and managers is an important output from the Torres Strait Geographic Information System..


Methods

The Torres Strait Atlas is a collation of numerous topographic entities and textual nomenclature into a document  that effectively bridges the communication gap between various stakeholders of the Torres Strait region.

Topographic  entities (graphics) have been collated from the 1:100,000 Australian Topographic Map Series and Landsat Thematic Mapper Satellite Imagery.

Placenames (text) have been appended from the Australian Gazette, information supplied by the Torres Strait Island Co-ordinating Council (via the MaSTER’s programme) and research into a wide range of publications.

The topographic map was systematically constructed using procedures that ensure quality assurance:

·      Topographic entities of the western and central Torres Strait (ie. west of the Warrior Reefs)  were created by digitising existing 1:100,000 scale Australian Topographic Maps.

·      Additional 100,000 scale maps were supplied for the Papua New coastline and near shore reefs and islands by the Papuan New Guinea government and subsequently digitised.

·      Quality assurance mechanism was assessed by randomly selecting well-defined points and correlating with the co-ordintes as per the original government published topographic map. The average variation between coordinates was tabled as 40 meters. Taking into consideration the stated spatial accuracy of the source material being 80 meters at 95% confidence interval then the reproduced Torres Strait digital  database can be stated to have a spatial accuracy of 120 meters at the 95% confidence interval. 

·      The reefs and islands of the east and south east region of the Torres Strait not covered by 100,000 scale topographic maps were digitised by CSIRO using Landsat Thematic Mapper Satellite Imagery.

·      Landsat Thematic Mapper scene identifier;  Path 98 Row 67; date: 10/11/92, 10 am

·      Scene is 180km * 180 km in size at a resolution of 25 meters.

·      Imagery contrast enhanced by maximising contrast in bands 1(blue), 2 (green) and 3 (red). This permits effective visualisation of spectral variations such as deliation of reefal areas against a backdrop of deep water.

·      Imagery rectified and resampled to geo-reference into a suitable co-ordinate system and to permit use as a backdrop to other maps. Root mean square (RMS) error in rectification was 16 meters.

·      Reef areas ‘heads-up’ digitised by CSIRO staff knowledgable of the physical and biological characterics of the region.

·      Areas obstructed by cloud cover were either interpolated with expert knowledge or flagged for cautions and future reference.

·      The two digital topographic datasets were merged and conservatively assigned an accuracy of 150 meters with a 95% confidence interval to account for propagated errors within production and errors within the  GIS. 

The Queensland Place Name Gazetteer File was purchased fron the Department of Natural resources and incorporated into the Torres Strait GIS. The Gazetteer consists of geo-referenced place names as displayed in all official government maps.

A systematic approach was used to attribute relevant entities with place names:

·      Names commonly used by Torres Strait inhabitants were supplied as text on existing Nautical Charts. This information was supplied by the Torres Strait Island Co-ordinating Council (via the MaSTERS programme).

·      Placenames identified in a wide range of publications were correlated with the corresponding topographic entity and labelled.

·      All topographic  entities were systematically labelled by correlation and interpolation of the available place names with the corresponding spatial entities.

·      Over 390 gazette names were affixed to corresponding entities, with an additional 160 traditional placenames and another 190 names discovered in other references.

·      All entities were then graphically labelled to an annotation layer at a scale of 1:200,000. This annotation layer was then resized and edited to  remove overlapping labels in congested areas. Annotation was carefully aligned and rotated to best position each lable to the corresponding entity.

·      The basemaps produced are at scales suitable for complete coverage of all known nomenclature to date and have been saved as graphical files suitable to bulk download to commercial output devices presently available.


Results and Discussion

The appended hardcopy output has been made available by recent acquisition of quality colour printers and maps are now in a production format for efficient delivery.

It is hoped that this series of topographic maps will effectively facilitate communication between inhabitants, managers and stakeholders of the Torres Strait region.

It is important to note that the maps supplied are not for navigational use. The relevant Nautical Charts as published by the Australian Hydrographic Service must be used for navigation.

Though due care has been taken as in the GIS Agreement, CSIRO does not warrant that this information is free from any errors or omissions.

Feedback from users will further develop the Atlas into a cohesive reference for all. Any errors or omissions should be directed to CSIRO Marine Research, Cleveland GIS Facility.

Maps                   Legal Notice and Disclaimer

The Torres Strait Atlas can be viewed in numerous ways.

Any comments or corrections can be emailed to Tom.Taranto@csiro.au

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PDF format maps

                           Torres Strait Atlas Keymap

1:500,000 Scale Maps                                           1:200,000 Scale Maps

Thursday Island and surrounds                                Thursday Island and surrounds

Turnagain Island and surrounds                              Moa Island and surrounds

South East Torres Strait                                           Mabuiag Island and surrounds

North  East Torres Strait                                          Adolphus Channel and surrounds