Digital soil maps for key soil properties over New South Wales, version 1.2

Digital soil maps (DSMs) are prepared through quantitative modelling techniques that are based on relationships between soil attributes and the environment. DSMs are presented over NSW for a range of key soil properties, including soil organic carbon (SOC), pH, cation exchange capacity, sum-of-bases, total phosphorous, electrical conductivity (EC), exchangeable sodium percent (ESP), clay, sand and silt. The maps are at 100 m spatial resolution and cover six soil depth intervals down to 2 m, consistent with standard international systems, plus 0-30 cm and 30-100 cm layers. The modelling techniques applied included multiple linear regression and Cubist decision tree approaches. Validation results for the maps indicate generally moderate performance and effectiveness. The maps provide at least a useful first approximation of these soil properties across the State. The products are described more fully in the technical report: OEH (2018), Digital soil mapping of key soil properties over NSW, version 1.2 (40p). The 0-30 and 30-100 cm raster layers, plus 0-5 cm rasters for textural properties (660 and 840 MB zip files) or jpeg images (63 MB zip file) can be downloaded through the NSW SEED data portal. They are also viewable through eSPADE (http://espade.environment.nsw.gov.au). The full suite of depth layers for all soil properties are available through the OEH data broker.