The first edition of the ASGC had an effective date of 5 July 1984 and adopted the geographical areas already in use in the ABS for some time prior to that date. In 1988, the ASGC underwent a review and most of the findings were incorporated into the 1991 edition of the ASGC. A further review of the ASGC commenced in early 1996 and was completed in 1997. This review did not result in any changes to the ASGC spatial units or their delimitation criteria. However a decision was made to review the existing capital city SDs, and S Dists, to ensure they will meet statistical requirements for at least the next twenty years. Sections of State were also reviewed to determine additional classes for the Urban Centres. The outcomes of these reviews have been implemented in this ASGC 2001 Edition.
Prior to 1993, the ASGC was updated on an as-needed basis which generally resulted in updates occurring once or twice a year. Since 1994, the ASGC has been updated annually (with the exception of 1997, in which no update occurred) with an effective date of 1 July. The nine editions of the ASGC manual between 1984 and 1990 were known as Edition 1 to Edition 9. By contrast, the five editions between 1991 and 1995 were known as Edition 2.1 to Edition 2.5. From 1996, the ASGC edition is known by the year it becomes effective, e.g. the 2001 Edition.
Earlier editions of the ASGC manual were kept up-to-date by the issue of replacement pages. Editions 1 to 9 formed one series of editions. Similarly, Edition 2.1 was the base edition for the second series of ASGC manuals, which included Editions 2.1 to 2.5. The 1996 Edition was published as part of a three-volume set of Statistical Geography publications relating to the 1996 Census. The 1998, 1999 and 2000 Editions were each published as a single volume. The 2001 Edition is published as part of a three-volume set of Statistical Geography publications relating to the 2001 Census.
SPATIAL UNIT AND CODE CHANGES
Essentially, the ASGC is updated in response to two types of changes:
- Externally controlled spatial unit changes. These changes relate to administrative or political areas which have been adopted as spatial units in the ASGC. The ABS has no control over changes to these types of spatial units. The most usual changes of this type are changes to LGAs made by State and Territory Governments. These changes can range from LGA boundary variations to the creation or amalgamation of whole LGAs and usually require consequential changes to related ASGC spatial units such as SLAs.
Changes in spatial units are often, though not always, accompanied by changes to the spatial unit codes. Therefore it is important when referencing spatial units in publications or tabulations, to quote the ASGC edition as well as the names and codes of these units. The main causes of spatial unit code changes between ASGC editions are:
- All other changes. These cover changes to ABS-defined spatial units, such as SLAs created within LGAs or changes to SSD boundaries, or changes to the principles and criteria which govern the delimitation of these spatial units. On occasion, changes of this type are triggered by changes to administrative or political areas described above. More usually, changes of this type result from ad hoc or systematic reviews.
Coordination of ASGC maintenance
Maintenance of the ASGC and ASGC-related material and products is shared by a number of projects within the ABS Central and State Offices. It is coordinated by Geography Section which also has responsibility for the ASGC manual and the National Localities Index (Chapter 12), as well as providing assistance to users.
- changes to spatial unit areas, especially where changes are significant;
- spatial unit name changes, especially in the case of LGAs and SLAs;
- consequential changes i.e. where one change forces another; and
- general code structure revisions.