Notes - geography
Census geography overview
Census data is available at a variety of different geographic levels such as State, Capital City, Local Government Area, Suburb and Postal Area. These areas are created by aggregating smaller units of geography together into a 'best fit.'
The boundaries available from the ABS rarely match actual 'communities', 'suburbs' or 'service catchments' needed for effective decision making, and even if they do, they are seldom available on the same geographic basis over time, making it very difficult to identify trends in population characteristics based on meaningful areas.
For the 2011 Census, the Australian Bureau of Statistics (ABS) implemented a brand new geographic structure, which is based on labour force areas. This is known as the Australian Standard Geography Standard, and uses the base unit of the SA1 (Statistical Area Level 1). These build into SA2s, SA3s, SA4s and Greater Capital City Areas.
For previous Censuses the base building block was called a Census Collector District. Census Collector Districts aggregated to Local Government Areas.
Local Government Areas are available from the 2011 Census output. They are created by aggregating SA1s. However these SA1s do not sum exactly to Local Government boundaries, making geographic breakdowns problematic, and time series even more difficult.
profile.id resolves all of these issues to create a meaningful geography that can be analysed over a long time period.
This profile provides Census data for Australia broken down into small areas based on customised suburbs/localities.
For the 1991, 1996, 2001 and 2006 Census years these small areas are created by aggregating Census Collection Districts. For the 2011 Census they are created by aggregating Statistical Area Level 1 units.
Where SA1s or CCDs do not fit exactly into a suburb or locality boundary, estimates are made in each Census year of the number of dwellings to be included. These estimates use aerial photography, dwelling counts, planning schemes, and street directories to determine what percentage of each SA1 or CCD to include in the suburb.
This means that regardless of the Census year, and the changes in ABS output boundaries, the data presented in profile.id exactly matches the suburb/locality boundary. This provides the most accurate population information for suburbs and localities and a meaningful time series for the current geography.
NOTE: The geography in the Community Profile tables may not match the Australian Bureau of Statistics (ABS) SA2, state suburb or postal area boundaries, which are based on aggregation of whole SA1s and are not comparable to previous Census years.