National Wilderness Inventory

Australia: Our national stories
Australian Heritage Commission, 2003
ISBN 0 642 23561 9

3. The Primary Database (continued)

3.2 Primary Database Structure

The key to producing wilderness assessments in the NWI is effective maintenance and management of the primary database.

This is complex for the NWI as primary data is derived from information with large disparities in areal extent and quality. To assist in primary data management the ARC/INFO Librarian facility was used (the computing environment is described more fully in Section 2.4).

Within Librarian, primary data is stored spatially in tiles which correspond to the 1:250 000 survey unit framework (Figure 3.1).

Not all primary data is held within the Librarian structure. In certain instances (which apply only to 'non-arid' Biophysical Naturalness assessment procedures) specialized local or regional data sets have been used in analysis. These data sets are generally not amenable to management within the Librarian structure and are maintained separately within the NWI file system. The NWI primary database layers are described in Table 3.1.

Table 3.1: Primary Data Library Layers
Primary Data Layer Description Usage
land_cov All polygonal land cover information; including natural cover, cultural cover, built up areas, reservoirs etc. For use in establishing areas for wilderness quality survey (natural areas), and in calculating Remoteness from Access, Remoteness from Settlement, Apparent Naturalness, and Biophysical Naturalness (in 'arid' analysis areas).
lines All linear information required for wilderness analysis; including roads and tracks, railways, other linear infrastructure (and linear water features for 'arid' analysis areas) etc. For use in calculating Remoteness from Access, Apparent Naturalness and Biophysical Naturalness (in 'arid' analysis areas).
points All point features required for wilderness analysis; including settlements, buildings, other point infrastructure, (including water points in 'arid' analysis areas) etc. For use in calculating Remoteness from Access, Remoteness from Settlement, Apparent Naturalness, and Biophysical Naturalness (in 'arid' analysis areas).
pastoral Land tenure information regarding pastoral use of land; distinguishing sheep/cattle/non grazing tenures. For use in deriving Biophysical Naturalness in 'arid' analysis areas.
rangetype Range suitability derived from Northcote soil/landscape units and land-systems and vegetation mapping. For use in deriving Biophysical Naturalness in 'arid' analysis areas.

Within the library structure these primary data layers are stored as double precision coverages, in Lambert's Conformal Conic projection. Projection parameters and the cover and item specifications for the library are indicated below. Each layer has two attributes or items that directly relate to wilderness analysis. The first item (as specified in Table 3.2) contains the NWI attribute code, the second item (source) indicates the source of the data.

Projection: Lambert's Conformal Conic
Units: metres
Spheroid Clark 1866
1st standard parallel -20 0 0
2nd standard parallel -32 0 0
Central meridian 135 0 0
Latitude of origin -48 0 0
False easting 0
False easting 0
Table 3.2: Primary Database Layer Specifications
Layer Name Cover Name Item Name INFO Item Definition
land_cov land_cov cover
source
4 5 B
20 20 C
lines lines access
source
4 5 B
20 20 C
points points range
source
4 5 B
20 20 C
rangetype northcote range
source
10 10 C
20 20 C
pastoral pastoral stock
source
4 5 B
20 20 C
Note: Data source information associated with these components of the primary database are described in further detail for each State in the appendices, whilst feature coding information is outlined in Section 3.4