Australia: Our national stories
Australian Heritage Commission, 2003
ISBN 0 642 23561 9
4. Creating The Wilderness Database (continued)
4.4 Wilderness Quality
A total wilderness quality index is produced by summing the standardized values obtained for the three distance-based wilderness quality indicators, truncated at a maximum of class 5, and the Biophysical Naturalness value. Values are calculated for each lattice sampling point, and the resulting value assigned as a permanent attribute of the wilderness database.
A wilderness quality estimate may be produced by combining indicator class values. The standard process is additive, resulting in a total wilderness quality scale ranging from minimum to maximum indicator class value combinations. This procedure rests on the assumption that each indicator contributes independently and equally to total wilderness quality. If it is considered that the indicators being added are of differing importance in contributing to total wilderness quality, or where special emphasis is required for some other reason, weighting may be introduced to the additive process.
For the purposes of NWI baseline surveys each survey indicator is assumed to be equivalent, and indicator values are summed accordingly. The additive process may also incorporate procedures which ensure wilderness quality assessments meet specific requirements. For instance, minimum thresholds for each indicator may be applied to ensure the exclusion of areas which do not meet minimum levels of remoteness and naturalness.
The process of deriving a total wilderness quality index is illustrated in Figure 4.5.
The timetable followed in completing wilderness surveys is shown in Figure 4.6.