Soil depth DSM data of the Fitzroy catchment WA, Darwin catchments and Mitchell catchment Qld generated by the Northern Australia Water Resource Assessment

Soil depth is one of 18 attributes of soils chosen to underpin the land suitability assessment of the Northern Australia Water Resource Assessment (NAWRA) through the digital soil mapping process (DSM). Soil depth indicates the soils physical depth to impediment eg bedrock or impenetrable layers. This soil depth raster data represents a modelled dataset of soil depth presented as a positive number in meters eg a value of 1.12 shows the soil depth is 1.12m deep and is derived from measured site data and environmental covariates. This data may underrepresent areas of soils deeper than 1.5m as the input data was mostly only recorded to a maximum of 1.5m where achievable being the extent of the hydraulic soil corer and the general agricultural soil depth. The soil depth data for the Fitzroy catchment has been modelled as a categorical dataset of five classes as this model performed better across the catchment with the limited input data available. The Fitzroy soil depth codes are consistent with the land suitability rules and the Australian Soil Classification soil depth classes: 0.25 is <25cm soil depth, 0.5 is 25 – 50cm soil depth, 1 is 50cm to 1.0m soil depth, 1.5 is 1.0m to 1.5m soil depth, 5 is >1.5m soil depth. Soil depth is a parameter used in land suitability assessments for plant edaphic requirements (root development and structural growth) and physical support and a component in other limitations including PAWC. This raster data provides improved soil information used to identify opportunities and promote detailed investigation for a range of sustainable regional development options and was created within the ‘Land Suitability’ activity of the CSIRO NAWRA. A companion dataset and statistics reflecting reliability of this data are also provided and can be found described in the lineage section of this metadata record. Processing information is supplied in ranger R scripts and attributes were modelled using a Random Forest approach.
The DSM process is described in the CSIRO NAWRA published report ‘Digital soil mapping of the Fitzroy, Darwin and Mitchell catchments. A technical report from the CSIRO Northern Australia Water Resource Assessment to the Government of Australia'. The land suitability assessment this dataset underpins is described in the CSIRO NAWRA published report ‘Land suitability of the Fitzroy, Darwin and Mitchell catchments. A technical report from the CSIRO Northern Australia Water Resource Assessment to the Government of Australia'.