Robin J. Beaman1, Grant Boyes2 and Mark Alcock2 1College of Science Technology and Engineering, James Cook University, Cairns, Qld 4870, Australia. Email: robin.beaman@jcu.edu.au 2National Location Information Group, Geoscience Australia, Canberra, ACT 2601, Australia

1 Seminar to QCON14 – Cairns, Qld, Australia, 8 October 2014

mailto:robin.beaman@jcu.edu.au

Seminar outline • Background of the Project • Maritime boundary definitions • Australian Maritime Boundaries 2006 • Source datasets for the Project • Background datasets for the Project • Case study at Arden Islet • Vision for Australia’s marine space

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Background In 2012, a National Collaboration Framework Project Agreement

between the Commonwealth of Australia (Geoscience Australia), and the State of Queensland (Department of Natural Resources and Mines), called the Queensland Coastline Capture Project.

Goal of the Project is to facilitate the derivation of a robust and jointly agreed definition of the territorial sea baseline for Australia around the Queensland coastline.

In 2013, a partnership with James Cook University to facilitate the capture of the low-water line at Lowest Astronomical Tide of coral reefs in the GBR for territorial sea baseline purposes.

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Maritime boundary definitions

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Territorial sea baseline (TSB) refers to the line from which the seaward limits of Australia's Maritime Zones are measured.

Includes the breadth of the territorial sea (TS); the seaward limits of the contiguous zone (CZ), the exclusive economic zone (EEZ) and, in some cases, the continental shelf (CS).

Coastal waters (CW) is a belt of water between the limits of the Australian States and the Northern Territory and a line 3 NM seaward of the territorial sea baseline.

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For Australia, the low-water line refers to Lowest Astronomical Tide (LAT) and underpins the territorial sea baseline from which the seaward limits of Australia’s Maritime Zones are measured.

The normal baseline can be drawn around low-tide elevations (LTE), which are defined as naturally formed areas of land surrounded by and above water at low tide but submerged at high tide, provided they are wholly or partly within 12 nautical miles of the mainland or an island.

Reefs can also be defined as a low-tide elevation if exposed at low tide but submerged at high tide, with the TS measured from the seaward low-water line, as per above.

Islands can be defined as a naturally formed area of land, surrounded by water, which is above water at high tide. For islands with fringing reefs, the baseline for measuring the breadth of the TS is the seaward low-water line of the reef.

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AMB2006 - TSB

AMB2006 - TSB, CW

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AMB2006 - TSB, CW, LTE

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AMB2006 - TSB, CW, LTE, TSL

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AMB2006 - TSB, CW, LTE, TSL, reefs Note, large gaps in TS limit across the GBR

AMB2006 – Yule Entrance

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TS limit

no TS reefs (LTE)

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AMB2006 – Yule Entrance

no TS

TS limit

reefs (LTE)

Source data – Aerial imagery

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Geoscience Australia contracted AEROmetrex to conduct air photography over the Torres Strait, using a Vexcel UltraCamX large format digital aerial camera.

Timed to coincide within 0.5 m above LAT over coral reefs and islands.

Supplied as 3-band, 8 bit colour infrared (CIR) and red/green/blue (RGB) ortho-mosaic files at 0.3 m-resolution.

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Movie - low-water over reefs

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Source data – Aerial imagery

Source data – Airborne lidar bathy

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Surveys have been conducted on the GBR shelf, Torres Strait and Coral Sea since 1993, using the RAN LADS and Fugro SHOALS systems.

Surveys use the WGS84 horizontal projection with a vertical datum of LAT, based upon both predicted and observed tides using co-tidal models.

Supplied as both full-resolution 6 m point spacing and 12.5 m decimated datasets.

Low-water line will be derived from high-res DEMs.

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Source data – Airborne lidar bathy

current reefs (LTE)

Background data – ALOS PRISM

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ALOS PRISM panchromatic data mosaics created by Geoscience Australia, called the Australian Geographic Reference Images.

Supplied as ecw mosaics as UTM54S, 55S, 56S projected scenes using the WGS84 datum at 2.5 m-resolution.

Data captured at various tidal heights so limited use to capture low-water lines, but useful to confirm existence of reefs/islands.

Background data – Aus charts

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Aus charts are Australia’s official navigation charts for the Great Barrier Reef and Coral Sea area.

WGS84 datum geotifs, using the most recent bathymetric surveys conducted by the Royal Australian Navy.

Useful indication of the existence, or otherwise, of shallow reefs to target for deriving their low-water lines.

Background data – gbr100 grid

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Grid is a digital elevation model of the Great Barrier Reef and Coral Sea, available for download from: http://deepreef.org/bathymetry/65-3dgbr-bathy.html

Uses a mean sea-level (MSL) vertical datum and WGS84 horizontal datum at 0.001 dd-resolution (~100 m).

Hillshaded geotif provided another useful means of checking whether or not a shallow reef actually exists prior to targeting the reef for deriving the low-water line.

http://deepreef.org/bathymetry/65-3dgbr-bathy.htmlhttp://deepreef.org/bathymetry/65-3dgbr-bathy.html

Background data – Landsat etc.

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Landsat-7 data mosaics were supplied as img files by the Great Barrier Reef Marine Park Authority.

Images were ortho-corrected using the GDA94 datum at 0.000278 dd-resolution (~30 m).

Used to help identify the shallow reefs targeted for the delineation of their low-water line.

Additional WV2 provided by GA.

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Case study – Arden Islet

RGB true colour

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CIR false colour composite

Case study – Arden Islet

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RGB natural breaks slice

Case study – Arden Islet

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extract vegetation

Case study – Arden Islet

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extract sand cay

Case study – Arden Islet

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CIR natural breaks slice

Case study – Arden Islet

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extract low-water polygon

Case study – Arden Islet

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extract low-water line

Case study – Arden Islet

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compare current/new low-water lines

Case study – Arden Islet

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Vision for Australia’s marine space

http://www.ga.gov.au/scientific-topics/marine/jurisdiction/amsis

Arden Islet

RGB

CIR

low-water line

island

metadata

http://www.ga.gov.au/scientific-topics/marine/jurisdiction/amsis

Queensland Coastline Capture Project for Coral ReefsSeminar outlineBackgroundMaritime boundary definitionsSlide Number 5Slide Number 6AMB2006 - TSB, CWAMB2006 - TSB, CW, LTEAMB2006 - TSB, CW, LTE, TSLAMB2006 - TSB, CW, LTE, TSL, reefsAMB2006 – Yule EntranceAMB2006 – Yule EntranceSource data – Aerial imageryMovie - low-water over reefsSource data – Aerial imagerySource data – Airborne lidar bathySource data – Airborne lidar bathyBackground data – ALOS PRISMBackground data – Aus chartsBackground data – gbr100 gridBackground data – Landsat etc.Case study – Arden IsletCase study – Arden IsletCase study – Arden IsletCase study – Arden IsletCase study – Arden IsletCase study – Arden IsletCase study – Arden IsletCase study – Arden IsletCase study – Arden IsletVision for Australia’s marine space