Land capability classification is an internationally accepted method of ranking the ability of the land to support a range of broadacre agricultural activities on a sustainable basis. In Tasmania the system comprises seven classes ranked in order of agricutltural veratility. Class 1 land is the best and Class 7 the poorest. Classification requires the synthesis and land information including soils, topography and climatic data. DPIWE undertook two approaches to mapping. The first involved intensive field investigations and focussed on parts of the State most likely to include better quality land. Remaining areas were mapped using a computer modelling approach. The classification has been undertaken only for private freehold or leased Crown land and the results are published as 1:100 000 scale maps with, for the field mapped areas, accompanying reports. The maps are useful for State and regional planning though the system can be used at more detailed scales appropriate to local or even farm planning to support informed decision making.

This dataset and published map was developed using site visits, aerial photo interpretation, use of digital slope (elevation) models (40m), rainfall records and interpretation of soil and geology maps. These information sources were sourced from most recent records from a number of Agencies.

Position Accuracy: Digital dataset is true and within 25metres of actual location 90% of the time. Attribute Accuracy: The map is accurate at the published scale (1:100,000). No formal measure of the accuracy of the classification process has been undertaken. As per the land capability assessment procedure, land capability class is assigned to the landscape. As part of the process, 'other' land capability classes may fall within a unit. An informal measure of the accuracy of the dataset is 90%. Logical Consistency: True polygon topology has been built and all polygons have one label present. Completeness: The dataset is complete for private and non-allocated leased Crown land. Lands other than these are mapped as 'exclusion areas'. Small polygons of area less than 25 hectares have been dissolved into the surrounding land capability class due to the scale of mapping. Additional: Grose, C J, (unpub), Land Capability Handbook, Guidelines for the Classification of Agricultural Land in Tasmania. 2nd Edition, DPIWE, Tasmania. Australia.