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PURPOSE

The UC/L Structure groups CDs together to form defined areas according to population size criteria. The resulting areas are known as Urban Centres or Localities. Population counts (place of enumeration) from the latest Census of Population and Housing are used to define the UC/L Structure which means this classification structure is only current at the time of the Census. Both the Urban Centre and the Locality spatial units are made up of one or more contiguous CDs. As the UC/L Structure relates to CDs within defined areas only, the structure, in aggregate, does not cover all of Australia.

The UC/L Structure is used for the production of standard ABS statistical outputs from Population Censuses such as Selected Social and Housing Characteristics for Urban Centres and Localities (cat. nos 2016.0-7), CDATA 2001 (cat. nos 2019.0.30.001-2019.8.30.001).

The UC/L Structure is separate from the Main Structure because:

• the boundaries do not generally coincide with SLAs and the higher level spatial units in the Main Structure
• its total area covers only part of Australia.

CDs within this structure are confined to those within defined Urban Centre and Locality boundaries. As a consequence, Urban Centres and Localities aggregate to cover only part of a state or territory and thus the structure covers part of Australia only.

Urban Centres may be bisected by an S/T boundary. Where this occurs each portion of the urban centre is separately identified and is included in the Urban Centre/Locality Structure for the relevant S/T. For example, the urban centre of Albury-Wodonga is partly in New South Wales and partly in Victoria. One part is shown under New South Wales and the other under Victoria.

Table

Urban Centres and Localities are delimited by the use of actual population counts after each Census is conducted. The Urban Centres and Localities determined following the 2001 Census are listed in the publication Statistical Geography Volume 3 - Australian Standard Geographical Classification (ASGC) Urban Centres/Localities, 2001 (cat. no. 2909.0).

Example:

THE SPATIAL UNITS

Census Collection District (CD)

For discussion about this spatial unit see Main Structure.

Urban Centre/Locality (UC/L)

In broad terms, an Urban Centre is a population cluster of 1,000 or more people while a Locality is a population cluster of between 200 and 999 people. For statistical purposes, people living in Urban Centres are classified as urban while those in Localities are classified as rural.

Each Urban Centre/Locality has a clearly defined boundary and comprises one or more whole CDs. Urban Centres/Localities are redefined at each Population Census.

Delimitation of Urban Centres and Localities

The delimitation criteria for UC/Ls are based on those developed in 1965 by Dr GJR Linge from the Australian National University. The criteria that are currently in force have been adopted and subsequently amended by the Conferences of Statisticians of Australia in 1965 and 1969 and the Review of ABS Statistical Geography in 1988.

Delimitation of Urban Centres with 20,000 or more people

The criteria are as follows:

• Each Urban Centre with a population of 20,000 or more is to consist of a cluster of contiguous urban CDs and other urban areas. CDs classified as urban include the following:
  • All contiguous CDs which have a population density of 200 or more persons per square kilometre shall be classified as urban. Consequently State, SD, LGA and other administrative boundaries shall be disregarded in determining whether a CD should be included within the Urban Centre.
  • A CD consisting mainly of land used for factories, airports, small sports areas, cemeteries, hostels, institutions, prisons, military camps or certain research stations shall be classified as urban if contiguous with CDs which are themselves urban.
  • A CD consisting mainly of land used for large sporting areas, large parks, explosives handling and munitions areas, or holding yards associated with meatworks and abattoirs shall be classified as urban only if it is bordered on three sides by CDs which are themselves classified as urban.
  • Any area which is completely surrounded by CDs which are urban must itself be classified as urban.
  • Where an Urban Centre of 20,000 or more population is separated from another urban area by a gap in urban development of less than three kilometres (by the shortest railway or road distance), the gap shall be bridged by classifying a connecting CD as urban, and therefore treating the urban areas as one. If the gap is three or more kilometres (and whether or not it is comprised mainly of reserved land or a natural barrier) the urban areas shall remain separate.
  • Any area included in an Urban Centre in 1971 or thereafter under the provisions of these criteria shall continue to be so included, unless the population of the Urban Centre falls below 20,000, in which case these criteria will cease to apply.
  • If a CD was incorrectly included (for whatever reason) in a Linge area at a previous census, then it should be excluded at the next census unless it now meets the criteria.
  • Large peripheral CDs in growth areas may be fragmented; and insofar as the availability of visible boundary features allows, the fragments so created shall be as near square-shaped as possible, contain at least 100 persons at the next census and be of such a size that they will contain a collector’s workload when fully developed. For the purpose of delimiting Urban Centres such fragments shall be regarded as CDs.

• The Urban Centre shall be delimited subjectively by the inspection of aerial photographs, by field inspection and/or by consideration of any other information that is available.
• All contiguous urban growth is to be included (even if this would not necessarily occur if the density criterion were applied), together with any close but non-contiguous development which could be clearly regarded as part of the Urban Centre. However, for Urban Centres which contain a population approaching 20,000 the objective criteria applied for Urban Centres with 20,000 people should also be considered.

• All population clusters of less than 1,000 population and whose population is expected to reach 200 by the next census are to be examined for boundary delineation.
• The following criteria must be satisfied before a boundary is drawn around a Locality. It must:
  • contain a non-farm population of at least 200 people but not more than 999 by the next census
  • have a minimum of 40 occupied non-farm dwellings with a discernible urban street pattern
  • have a discernible nucleus of population.
• If there is some doubt that a Locality will reach the minimum population of 200 people then a boundary should still be drawn around the Locality.
• Where, in the case of defence camps, construction camps, etc. it is anticipated that the cluster will not exist at two consecutive censuses, these camps should not be bounded.
• The Localities shall be delimited subjectively, by the use of the latest available aerial photographs, by field inspection and/or by consideration of any other information that is available.

• Wide rather than narrow boundaries are to be used to ensure inclusion of all urban or built-up areas. Some rural area can be included in an Urban Centre, if necessary, to ensure that the boundary encompasses all the urban area. However, this guideline should be interpreted in the light of the ones that follow.
• Continuity of urban development is a major consideration. Boundaries are not to be thrown very wide just to include some small non-contiguous area of urban development. (The Linge criterion of three kilometres may be of assistance in this respect in larger Urban Centres of say greater than 10,000-15,000 population).
• Where the subjective boundaries decided upon are contained within a municipal boundary and the remaining area or population is small, the municipal boundary is to be used.
• For previously bounded cities, towns or localities the boundaries are not to be changed lightly. Comparability is to be maintained with the past unless there are significant exclusions (either due to faulty boundaries at the previous census or subsequent development).
• When considering urban land usage, recognition should be given to approved plans.
• Topographic boundaries must be used wherever possible when they are consistent with the above guidelines.

UC/Ls are identified by a five-digit code which is only unique within each State/Territory. Use of UC/L codes in conjunction with S/T codes is necessary before these codes become unique across Australia.

Example:

The code 99999 is not applicable for the ACT or the OT as off-shore, shipping & migratory CDs are not defined for those Territories.

State/Territory (S/T)

For discussion about this spatial unit see Main Structure.