Surface Cover

Disclaimer

Geoscape Australia believes this publication to be correct at the time of printing and does not accept responsibility for any consequences arising from the use of the information herein. Readers should rely on their own skill and judgement to apply information to particular issues.

This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no part may be reproduced by any process without prior written permission of Geoscape Australia.

Overview

Surface Cover is a raster dataset representing land cover categories across Australia. Urban Surface Cover has coverage in pre-defined urban locations across Australia at 2 metre resolution, while the National Surface Cover has complete national coverage at 30 metre resolution.

Geoscape Australia welcomes your feedback on the Surface Cover Dataset. We also publish regular product development updates on our website (www.geoscape.com.au).

Release Summary

This product was released to customers on 20 December 2023 with data extracted on 6 December 2023.

• This release is a full national data population for Version 1.8 of the Surface Cover product, described by the Surface Cover Product Description v1.8.

Any issues that have been identified for this release are described in the Issues section.

This release includes updates for the areas listed in the table below.

Locations of updated areas by State.

State	Location [1]	Urban Area (km2)
NSW	Broken Hill City Council	50
NSW	Federation Council	20
NSW	Goulburn Mulwaree Council	59
NSW	Muswellbrook Shire Council	20
NSW	Singleton Council	48
NSW	Unincorporated - Far West Area	1
VIC	Indigo Shire	14
VIC	Latrobe City	27
VIC	Mornington Peninsula Shire	299
WA	City of Albany	111
WA	City of Kalgoorlie-Boulder	48
WA	Shire of Esperance	35
Total		732

[1]

Location names are derived from an intersection with the most recent Local Government Area dataset, Geoscape, 2023.

Spatial files of the updated areas are available upon request via support@geoscape.com.au.

Change Notifications

Removal of the ‘Documents’ folder from data packages

From November 2023, Geoscape will be progressively moving product descriptions, guides and reports online to https://docs.geoscape.com.au

Commencing with the May 2024 release, data packages will no longer include the Documents folder.

Issues

New Issues

No new issues to note.

Resolved Issues

No resolved issues to note.

Known Issues

The progress and status of known, ongoing issues are summarised below. For specific and further details on each issue, please refer to the Release Report identified in the ‘Release identified’ column.

Ongoing product issues

Release Identified	Theme - Issue Name	Issue Brief Description	Progress/Resolution	Status
Dec-16	Building - Tree heights near buildings and other trees	Terrain elevation values used in the calculation of tree heights have been found in some cases to be affected by the surrounding tall features such as buildings and other trees.	No update at this time.	Open
Apr-17	Urban and National Surface Cover - Shadow and Cloud	An increase in the amount of shadow found in the Surface Cover layer, in some circumstances, has impacted on the shape and height of buildings as well as surface cover and trees.	Geoscape has worked with its partners to limit the capture and use of imagery that contains significant cloud and shadow for future releases. The future maintenance programs will be targeting areas affected by significant cloud and shadow.	Open
Nov-21	Trees over-capture	On Buildings, it has been observed that there are some situations where significant portions of some roofs have been captured as tree features. This is different from actual tree overhang and may be due to some combination of building proximity to trees, dark roof colour and/or shadow across roofs. Tree features in Surface Cover, where they intersect with buildings, are retained and represented over building features. This is because tree over-hang does exist in the real world, and also to ensure these tree pixels correspond to the Trees product. In Dense, Shadowed and Water Areas, the spectral signature of these areas can incorrectly result in features being extracted as trees during remote sensing. Height calculation can help to exclude the majority of these during production, but where heights are determined to be greater than 2 metres they may persist.	We are working with our partner to limit these occurrences, as well as improving our processes to identify and correct the situations where they are present.	Open
Nov-21	Updates based on Tree and Buildings classes	Since November 2021 Updates are limited to Building, Tree and Unspecified Vegetation classes according to the captured aerial imagery for the Trees and Buildings products. If a building or tree pixel is no longer covered by building or trees features according to the update, it will be converted to Built-up Areas or Unspecified Vegetation, respectively. Where pixels are covered by Buildings, Trees or Unspecified Vegetation according to the update, they will be retained or updated accordingly.	Methods and sources to update additional Surface Cover classes beyond Building, Tree and Unspecified Vegetation are currently being investigated.
Jun-22	Over classification of building class	The building classification in areas updated for the November 2021 and March 2022 releases have not received the improved aerial building representation.	Resolved for updated areas in the June 2022 and November 2021 and March 2022 will be resolved in a future release.

Future Considerations

This section outlines enhancements or changes under consideration, but not planned into a specific release. For further details on future initiatives, please contact Geoscape Support.

Annex A – Release Counts

Urban Surface Cover Coverage

Total coverage of Urban Surface Cover by type

Code	Description	Total Area (km2)
2	Bare Earth	13,424
3	Road and Path	2,040
4	Grass	10,606
5	Trees	9,887
6	Unspecified Vegetation	8,791
7	Built-up Areas	1,386
8	Water	2,204
9	Buildings	3,526
10	Cloud	4
11	Shadow	384
12	Swimming Pool	32
13	Car Park	49
National		52,333

Total coverage of Urban Surface Cover by state

State	Total Area (km2)
ACTNSW	17,761
NT	986
QLD	12,956
SA	3,711
TAS	1,793
VIC	9,830
WA	5,297
National	52,333

References

[Aerometrex, 2023]

Aerometrex. Aerial imagery. Raster Dataset, 2023. URL: https://aerometrex.com.au/.

[Geoscape, 2023]

Geoscape. Local government areas. 2023. URL: https://docs.geoscape.com.au/projects/lga_guide/en/stable/index.html, arXiv:https://docs.geoscape.com.au/_/downloads/lga_guide/en/stable/pdf/.