Vegetation cover condition (Cooper region)

Abstract

Vegetation cover condition is an assessment of how much impact disturbances (including management activities) have had on ground cover. Condition is assessed using Compere, a relative performance bench marking framework that compares one location's value to the values of all biophysically equivalent locations in a given region. Resulting condition estimates range from 0 (lowest observed cover among equivalents) to 1 (highest observed). Underlying total vegetation cover data are the total fraction of ground covered by green and senesced plant material (Guerschman et al., 2018, Remote Sensing of Environment 113, 928-945). Cover condition has been assessed yearly from 2001 to 2018 at a grid resolution of 500 m.

Attribution

Geological and Bioregional Assessment Program

History

Annual rainfall, historical NDVI (Normalised Difference Vegetation Index), slope and total cover fraction data were used to calculate cover condition. Annual rainfall was from the Bureau of Meteorology daily 5 km gridded data (Jeffrey et al., 2001). NDVI was from MODIS MOD13Q1 and MOD09Q1 data. Slope was from the CSIRO’s SRTM 9 digital elevation model data (Gallant et al., 2011). Cover was from CSIRO’s fractional cover data (derived from MCD43A4 data, Guerschman and Hill, 2018). Surface Water Points data and the Sturt National Park boundary data were used to test results. These were sourced from Crossman and Li (2015) and Commonwealth of Australia (2019), respectively. Background NDVI, slope and annual rainfall were used quantify locations that were biophysically equivalent to a given target location. The total cover fraction of the target was compared to that from all ‘equivalent’ locations to yield a relative ranking of the target’s cover value. This is interpreted directly as cover condition. This was repeated for all locations (grid cells) and years. An assessment of the impact of the mining industry on cover condition across the Cooper region was undertaken, using confidential well location data. See associated publications for more details. Jones, D.A., Wang, W., & Fawcett, R. (2009). High-quality spatial climate data sets for Australia. Australian Meteorological and Oceanographic Journal, 58, 233-248. Gallant, J.C., Dowling, T.I., Read, A.M., Wilson, N., Tickle, P.K., & Inskeep, C. (2011). 1 second SRTM-derived Digital Elevation Models User Guide. Canberra: Geoscience Australia. Guerschman, J.P., & Hill, M.J. (2018). Calibration and validation of the Australian fractional cover product for MODIS collection 6. Remote Sensing Letters, 9, 696-705. DOI: 10.1080/2150704X.2018.1465611. Crossman, S., & Li, O. (2015). Surface Hydrology points (Regional). Geosciences Australia. Canberra. http://pid.geoscience.gov.au/dataset/ga/83132. Commonwealth of Australia (2019). Collaborative Australian Protected Areas Database (CAPAD) 2018. Commonwealth of Australia. Canberra.