NSW Woody Vegetation Extent 2011

The NSW 5m Woody Extent is a state-wide binary classification of woody vegetation derived from multitemporal 5m SPOT-5 satellite imagery. The product broadly identifies isolated tree crowns as well as contigous forest at a 5m resolution.

This latest map of woody vegetation extent for NSW is the highest detailed to date. It shows the location and extent of woody vegetation in NSW for the year 2011. It can be used to identify small features such as paddock trees and trees in scattered woodlands, to the largest expanses of forest in the state. It is intended for use in non-urban environments and its accuracy for urban environments has not been assessed.

The dataset is also used as a spatial constraint for a seamless map of woody foliage projection cover (FPC). FPC is the fraction of the ground that is obscured by green leaf, and is a measure of density. The FPC dataset is delivered as a separate map to the woody extent (although it is constrained by it), and it can also be requested from the OEH data broker.

The woody extent product was derived from user-driven thresholds on an index of woody probability. The probability was calculated from a binomial logistic regression model on multi-temporal data. The model utilsed the statistics from SPOT-5 imagery over 2008-2012 and referenced over 26000 training points. Comprehensive manual corrections were also performed throughout 2013-2014 at a scale of 1:15000.

The dataset is provided in 8-bit raster format with the following attributes values: 1 = Woody 0 = Non-Woody 255 = null (either outside the NSW boundary or a perennial water feature)

Overall state accuracy is recorded at 90.1% when compared to Lidar datasets (see lineage for more information), and 88% when compared to 6670 visually derived validation points. Although this dataset has undergone extensive manual corrections, the accuracy for specific regions may vary considerably. http://www.auscover.org.au/xwiki/bin/view/Product+pages/nsw+5m+woody+extent+and+fpc