IMAS Metadata Catalogue
Habitat map of seagrass cover derived from a supervised moderate-spatial-resolution multi-spectral satellite image, integrated with manual delineation and coincident field data, Moreton Bay, 2011
A supervised classification was applied to a Landsat TM5 image. This image was acquired 9:40 am, on the 27th July 2011 (5.14 am low tide at Brisbane Bar). The image classification was applied on areas of clear waters up to three metres depth and for exposed regions of Moreton Bay. Field validation data was collected at 4797 survey sites by UQ. GPS referenced field data were used as training areas for the image classification process. For this training the substrate DN signatures were extracted from the Landsat 5 TM image for field survey locations of known substrate cover, enabling a characteristic "spectral reflectance signature" to be defined for each target. The Landsat TM image, containing only those pixels in water < 3.0m deep, was then subject to minimum distance to means algorithm to group pixels with similar DN signatures (assumed to correspond to the different substrata). This process enabled each pixel to be assigned a label of either seagrass cover (0, 1-25 %, 25-50 %, 50-75 % and 75-100 %). The resulting raster data was then converted into a vector polygon file. Species information was added based on the field data and expert knowledge. Both polygon files were joined by overlaying features of remote sensing files with the EHMP field data to produce an output theme that contains the attributes and full extent of both themes. If polygons of remote sensing were within polygons of field data the assumption was made that the remote sensing polygon was showing more detail and the underlying field polygon was deleted.
Simple
Identification info
- Date (Publication)
- 2017-04-27
- Date (Creation)
- 2012-07-03
Custodian
Remote Sensing Research Centre (RSRC), School of Geography, Planning and Environmental Management, The University of Queensland (UQ) - Biophysical Remote Sensing Group (BRG)
School of Geography, Planning and Environmental Management
The University of Queensland (UQ)
St Lucia
Queensland
4072
Australia
Custodian
Department of Environment and Heritage Protection, Queensland Government - Data Coordinator
PO Box 155
Brisbane Albert Street
Queensland
4002
Australia
- Status
- Completed
Point of contact
School of Earth and Environmental Sciences, The University of Queensland (UQ) - Roelfsema, Christiaan
Chamberlain Building (35), Room 416B
University of Queensland (UQ)
St Lucia
Queensland
3072
Australia
Spatial resolution
Equivalent scale
- Denominator
- 250
- Topic category
-
- Biota
Extent
N
S
E
W
))
Temporal extent
- Time position
- 2011-06-01T00:00:00
- Time position
- 2012-09-30T00:00:00
- Maintenance and update frequency
- Irregular
Resource format
- Title
- ESRI Shapefile
- Date
- Edition
- -
- Keywords (Theme)
-
- Moreton Bay Marine Park
- vegetation
- biota
- ecology
- estuarine
- Global Change Master Directory (GCMD) Earth Science Keywords Version 8.0
- Keywords (Place)
-
- Moreton Bay
- Keywords (Theme)
-
- Benthic habitat
- AODN Instrument Vocabulary
Resource specific usage
- Specific usage
- Data supplied for use by the Seamap Australia Project.
- ()
Resource constraints
- Classification
- Unclassified
Resource constraints
- Linkage
-
http://i.creativecommons.org/l/by/4.0/88x31.png
License Graphic
- Title
- Creative Commons Attribution 4.0 International License
- Website
-
http://creativecommons.org/licenses/by/4.0/
License Text
- Other constraints
- Cite data as: Roelfsema, Christiaan M; Kovacs, Eva M; Moffatt, David; Phinn, Stuart R; Hoseck, Steve (2015): Habitat map of seagrass cover derived from a supervised moderate-spatial-resolution multi-spectral satellite image, integrated with manual delineation and coincident field data, Moreton Bay, 2011, with link to shapefile. PANGAEA, https://doi.org/10.1594/PANGAEA.846271
- Other constraints
- This dataset is hosted by the Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, on behalf the University of Queensland for the purposes of the Seamap Australia collaborative project.
- Language
- English
- Character encoding
- UTF8
- Supplemental Information
- Roelfsema, Christiaan M; Lyons, Mitchell B; Kovacs, Eva M; Maxwell, Paul; Saunders, Megan I; Samper-Villarreal, Jimena; Phinn, Stuart R (2014): Multi-temporal mapping of seagrass cover, species and biomass: A semi-automated object based image analysis approach. Remote Sensing of Environment, 150, 172-187, doi:10.1016/j.rse.2014.05.001 Roelfsema, Christiaan M; Phinn, Stuart R; Udy, Nicola; Maxwell, Paul (2009): An integrated field and remote sensing approach for mapping Seagrass Cover, Moreton Bay, Australia. Journal of Spatial Science, 54(1), 45-62, doi:10.1080/14498596.2009.9635166
Content Information
- Content type
- Physical measurement
- Description
- Taxonomic identification of dominant seagrass species
Identifier
- Description
- Appended to original data for styling purposes for the Seamap Australia Project.
- Name
- Benthic habitat
- Name
- SM_HAB_CLS
Distribution Information
- Distribution format
-
- ESRI Shapefile
- OnLine resource
-
SHAPE-ZIP
DATA ACCESS - This OGC WFS service returns the data (Moreton Bay seagrass) in Shapefile format
- OnLine resource
-
seamap:SeamapAus_QLD_MoretonBay_seagrass_2011_MAP
MAP - Moreton Bay seagrass 2011 habitat map
- OnLine resource
- Original metadata record [PANGAEA catalogue]
Data quality info
- Hierarchy level
- Dataset
Report
- Measure description
- Polygons +/- 10m. Positional accuracy of polygon linework is noted in the field 'Pos_Acc' which gives a reliability code of high, moderate, or low confidence in accuracy for polygons derived from the EHMP field survey sites. The level is derived on the basis of positioning and the frequency of survey sites, the distinctiveness of discrete boundaries evident from the field surveys and the georeferencing accuracy of the satellite image.
Report
- Name of measure
- Attribute accuracy
- Measure description
- Attribute accuracy for the field denoting cover, is provided in the field “Att_acc”. It gives, for the polygons derived from the EHMP survey sites, a reliability code of high, moderate, or low confidence in accuracy. The level is determined on the basis of reliability of field observations. For polygons derived from the classification of the satellite image, attribute accuracy was achieved of “OA 41%”, which was considered “medium” level. Where OA stands for “Overall Accuracy” which is commonly expressed as the probability that a classified image pixel actually represents that category on the ground, and was calculated based on the independent field data set for the Eastern Banks area only. Attribute accuracy for the field denoting seagrass species is provided in the field “Att_acc_sp” which gives a reliability code of high, moderate, or low confidence in accuracy. This level is determined on the basis of reliability of field observations.
Report
- Name of measure
- Logical consistency
- Measure description
- All polygons visually checked at a scale of 1:500.
Resource lineage
- Statement
- Polygon boundaries and attributes derived from field and satellite image data. Field data Polygon boundaries digitised using information from 661 EHMP survey sites, Google Earth Downloaded Image and bathymetry data at scales ranging from 1:5000 depending on the size of the polygon. Satellite image polygon boundaries and attributes A supervised classification was applied to a Landsat TM5 image. This image was acquired 9:40 am, on the 27th July 2011(5.14 am low tide at Brisbane Bar). The image classification was applied on areas of clear waters up to three metres depth and for exposed regions of Moreton Bay. Field validation data was collected at 4797 survey sites by UQ. GPS referenced field data were used as training areas for the image classification process. For this training the substrate DN signatures were extracted from the Landsat 5 TM image for field survey locations of known substrate cover, enabling a characteristic “spectral reflectance signature” to be defined for each target. The Landsat TM image, containing only those pixels in water < 3.0m deep, was then subject to minimum distance to means algorithm to group pixels with similar DN signatures (assumed to correspond to the different substrata). This process enabled each pixel to be assigned a label of either seagrass cover (0, 1-25%, 25-50%, 50-75 % and 75-100 %). The resulting raster data was then converted into a vector polygon file. Species information was added based on the field data and expert knowledge. Both polygon files were joined by overlaying features of remote sensing files with the EHMP field data to produce an output theme that contains the attributes and full extent of both themes. If polygons of remote sensing were within polygons of field data the assumption was made that the remote sensing polygon was showing more detail and the underlying field polygon was deleted.
- Hierarchy level
- Dataset
Resource lineage
- Statement
- The field,'seagrass', provides a description of the visually estimated ground cover of the seagrass and is generally classed as either: • 0-25% cover (sparse) • 25-50% cover (low) • 50-75% cover (medium) • 75-100% cover (dense) The field,'species’, refer to the seagrass species occurring within each polygon. The field, ‘Source_type’ refers to how the attribute and spatial information was acquired and includes satellite image, snorkel, drop camera held over the side of a stationary vessel and expert knowledge. The field, ‘Source_data’ refers to the organisation / program responsible for data collection and analysis. The field, ‘Polygon’ refers to how the polygon was created. The field, ‘Rs_domain’ refers to the domain for which the image data is analysed (exposed regions or shallow clear waters).
- Hierarchy level
- Attribute
- Hierarchy level
- Dataset
Platform
Identifier
- Code
- orbiting satellite
Instrument
Identifier
- Code
- cameras
Metadata
- Metadata identifier
- d02b6f4e-c8b3-4983-b3c1-0b0d514b4a3d
- Language
- English
- Character encoding
- UTF8
Point of contact
- Parent metadata
Type of resource
- Resource scope
- Dataset
- Metadata linkage
-
https://metadata.imas.utas.edu.au/geonetwork/srv/eng/catalog.search#/metadata/d02b6f4e-c8b3-4983-b3c1-0b0d514b4a3d
Point of truth URL of this metadata record
- Date info (Creation)
- 2020-09-23T12:29:14
- Date info (Revision)
- 2020-09-23T12:29:14
Metadata standard
- Title
- ISO 19115-3:2018
Overviews
Spatial extent
N
S
E
W
Provided by
Associated resources
Not available