The main aim of the Statewide Landcover and Tree Study (SLATS) Program is to map the location and extent of woody vegetation loss each year. This information is then provided to land managers and policy makers for landcover monitoring and reporting.
Woody vegetation as defined for SLATS:
- produce wood as their primary structural tissue
- are typically trees, shrubs or woody vines (lianas)
- are usually perennial.
The SLATS method was adopted in 2006 after being developed and implemented in Queensland by the Department of Environment and Science. NSW adapted the method to suit current imagery availability and to meet reporting requirements and applications.
How we detect vegetation change
We use a combination of automated and manual mapping techniques to monitor woody vegetation loss.
The SLATS method is based on imagery from the European Space Agency’s Sentinel-2A and Sentinel-2B satellites that capture high-resolution images of the Earth’s surface every 5 days. A statewide raster layer is produced that indicates where woody vegetation has been cleared each year.
A raster layer is made up of grid or matrix of cells, also called pixels. In previous years this has been further processed for distribution as a point vector layer.
The satellites that have captured the imagery used in the SLATS program have changed over the years in response to changing technologies. Previously Landsat 5 and,7 and SPOT5 satellite sources were used. We currently use Sentinel satellite sources.
Results are assigned to a replacement landcover class, to indicate the purpose for which the vegetation was cleared. Assignment of these classes is primarily based on visual interpretation of the location and the pattern of the clearing with reference to supporting data sources such as tenure.