Australian Ground Cover Reference Sites Database - ABARES

Australian Ground Cover Reference Sites Database - ABARES

Map 1 Locations of published field sites with observations of fractional cover

Source: ABARES 2014, Australia ground cover reference sites database

Link to the data

Data licence and Access rights

Alternate title

A previously used 'Product page' title: MODIS fractional cover site data

Abstract or Summary

The ground cover reference sites database includes site descriptions and field measurements of the different cover fractions at sites across Australia. The data were collected by government agencies in all states and the Northern Territory as part of the 'Ground cover monitoring for Australia' project. This was an Australian Government Department of Agriculture project managed by the Australian Bureau of Agricultural and Resource Economics and Sciences (ABARES).

The Australian ground cover reference sites database (2014) contains 507 observations from 486 unique sites collected between July 2010 and June 2014. The one hectare sites are located in areas dominated by non-woody vegetation with tree canopy cover less than 20 percent. Land use at the sites is predominantly grazing and broadacre cropping mostly located in the rangelands. Field operators measured fractional cover using a national standard modified point-intercept method. The data are being used to calibrate, validate and improve vegetation fractional cover products derived from remote sensing, in particular the satellite sensors MODIS and Landsat. These fractional cover products can be used to monitor ground cover and assess environmental targets relating to soil erosion and land management.

Spatial and Temporal extents

Positional accuracy

Each field site is 1 hectare (100 x 100 metres) in size. The sites are chosen to be representative of the surrounding area to a MODIS pixel size of 500 x 500 metres, and to have been visited as close as possible to cloud free Landsat imagery collection. Standard GPS (not differential GPS) have been used to locate the centre point of the field site resulting in an estimated positional accuracy of approximately 25m depending on the device used.

Point of contact

Credit

These data have been collected by:

• New South Wales Office of Environment and Heritage, Department of Premier and Cabinet;
• Northern Territory Department of Land Resource Management;
• Queensland Department of Science, Information Technology, Innovation and the Arts;
• South Australia Department of Environment, Water and Natural Resources;
• Tasmania Department of Primary Industries, Parks, Water and Environment;
• Victoria Department of Environment and Primary Industries, and;
• Western Australia Department of Agriculture and Food.

Keywords

There are three main thesauri that AusCover recommends:

1. Global Change Master Directory (http://gcmd.nasa.gov)
2. Climate and Forecast (CF) convention standard names (http://cfconventions.org/standard-names.html).
3. Fields of Research codes (http://www.abs.gov.au/ausstats/abs@.nsf/0/6BB427AB9696C225CA2574180004463E?opendocument).

Data quality

The field data is intended to reflect the conditions in the field at the time of data collection in a consistent format. Data users should consider that there is a level of subjectivity in the observations which may vary between field operators and locations. Training sites are less reliable and incomplete compared to data collected once field operators became proficient in the transect and site description methods. Local conditions, operator experience, and equipment (such as GPS accuracy) all influence the observations. Most observations were taken visually and subsequent validation of species identity, biomass estimates and other attributes were not required. 

Validation status

Data have been checked for consistency by ABARES. The quality of the database is dependent on the quality of field data collected by field operators as described in Muir et al. (2011).

Sampling strategy

Data collection by state and territory agencies commenced in July 2010 and continued until June 2014. The ground cover reference sites database conforms to the methods described in Muir et al. (2011). Choice of site locations was informed by a sampling strategy (Malthus et al. 2013) and sampling protocols (Stewart et al. 2012; 2013.). Sites were to be located in areas dominated by non-woody vegetation with tree canopy cover less than 20 per cent under grazing or broadacre cropping land uses. The sampling strategy excluded areas with tree cover greater than 20 per cent, and non-agricultural land uses such as urban, conservation or indigenous land uses. Due to site and imagery access limitations some observations were collected in areas of land uses classed as national parks, nature conservation and traditional indigenous uses. The majority of sites are located in the rangelands.

Data completeness and update plan

The database contains 507 field site observations from 486 unique sites from the ‘Ground cover monitoring for Australia’ project that have permission to be published as at July 2014. This is an update of the database published in 2013. A total of 643 observations were collected under the ‘Ground cover monitoring for Australia’ project. Some project partners requested that field observations on private land not be published due to privacy concerns. The total number of observations collected by each state is shown in Table 1. The locations of the publishable sites in the database are shown in Map 1. 

Table 1: Number of observations in each state

Note: Data from unpublished sites may be acquired for specific research projects at the discretion of the relevant state agency. * Of the 119 observations collected by the Victorian Deparmtner of Environment and Primary Industries, 48 were directly funded through the Ground cover monitoring for Australia project.

The database may be updated if more observations are submitted to ABARES for processing or errors are reported.

Database file attributes

See the User guide 2014 for details.

Related products

References

See the User guide for additional references.

Product version history

Metadata history