Tamar report land Capability Survey of Tasmania k e noble 1992 Tamar Report

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4.

How to use this Map and Report

It is important that the land capability maps be used in conjunction with the accompanying

report.  Special attention needs to be given to reading and understanding the principles of the

land capability classification system, outlined in Sections 6 and 7 of this report.  By referring to

the map, and locating the area of interest, the land capability class assigned to that area can be

determined.  This is given by a number (1 to 7) which corresponds to the land capability class.

Descriptions of the land capability classes are given on the side legend of the map, and detailed

in Section 8.  Further detail about each of the land capability classes occurring on the Tamar map

is given in Sections 9 and 10, including explanatory diagrams showing the sequence of land

capability classes on different rock types.

4.1

Limitations of Scale

Special attention needs to be given to the limitations imposed by the scale of mapping.

It is important that the map be used at the scale at which it is published.  DO NOT ENLARGE

THE MAP.

Errors in interpretation will occur if the map is enlarged and there will be a reduction in

credibility of the information, as small areas would be delineated separately at a larger mapping

scale.  If more detail is required, the area of interest should be mapped at a larger scale rather

than enlarge the smaller scale map.

Regardless of the mapping scale used, there are always some areas which are too small to

delineate accurately.

At the map scale used in this survey, 1:100 000, the minimum area which can be adequately

depicted on the map represents approximately 64 ha on the ground.  Minimum widths of map

units are approximately 300 m at this scale of mapping.  However in some instances where it was

felt important to highlight areas of higher land capability classes, or in areas where the lack of

existing detail allowed separating out smaller areas, map units much smaller in size than 64 ha

have been delineated.

The areas of land capability classes shown on the maps are rarely made up entirely of the land

capability class indicated. They almost invariably contain areas of other land capability classes,

too small to depict at the scale of the map.  In complex areas, it is not possible to delineate these

smaller areas of other land capability classes.  In such circumstances the land is assigned to the

dominant class, but up to 30% of land of other classes may be included. In the majority of cases,

the land capability classes are estimated to be at least 80% pure, with more uniform areas having

inclusions of other classes limited to about 10%.

In some areas, two land capability classes may be mapped as a complex, where it has been

impossible at the scale of mapping to separate them, and they both occupy between 40 and 60%

of the area.  In this case both land capability class numbers are included on the map (e.g. 4 + 5).

The accuracy of the land capability boundaries depends on a number of factors including the

complexity of the terrain and geology.  In some cases the class boundaries may be well defined,

such as with abrupt changes in geology or topography.  Alternatively, changes may be gradual

and more difficult to assess such as with a change in soil depth, soil type, slope, or extent of

rockiness.  In these cases the boundary is transitional and therefore is less precisely plotted.

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4.2

Interpretation of the Land Capability Information

The scope and range of applications of the land capability information depends on the scale at

which the surveys are carried out.  A scale of 1:5 000 or 1:10 000 is suitable for whole farm

planning purposes, to plan farm layouts and to identify appropriate land uses, soil conservation

and land management practices.  A scale of 1:25 000 is suitable for catchment planning, and 1:50

000 or 1:100 000 scales for district and regional planning.

One of the major uses of this map series at 1:100 000 scale will be for local government, regional

and State land use planning decisions.  The information at this scale is not intended to be used to

make planning decisions at catchment or farm levels, although the information collected will

form a useful base for more detailed studies.

Examples of other potential uses of land capability information are:

-

Rational planning of urban and rural subdivisions

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Identifying areas for new crops, enterprises or major developments

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Identifying areas for expansion of particular land uses

-

Identifying areas of prime agricultural land (Classes 1 to 3) for retention for agricultural

use

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Planning for new routes for highways, railways, transmission lines, etc.

-

Identifying areas of land degradation, flooding or areas that may require special

conservation treatment

-

Identifying areas of potential erosion hazard

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Resolving major land use conflicts

Land capability information combined with other resource data, will be analysed, stored and

disseminated with the aid of a GIS (Geographic Information System). This will greatly enhance

the accessibility, interpretation and use of this information.

The applications of the land capability information do not depend solely on the maps themselves,

but also on the implementation framework - legislation and administration, which are responsible

for putting land use policies into practice.  The land capability maps and reports do not purport to

have legal standing as documents in their own right, nor should they attempt to stand alone in

planning decisions without being supported by other relevant land resource, economic, social or

conservation considerations.

4.3

Copyright

Both the maps and reports in this series are copyright, and the data is solely owned by the

Department of Primary Industry, Tasmania.

Anyone wishing to use any of the information contained in this report or accompanying map

should seek permission from the Secretary, Department of Primary Industry, Hobart.

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