This dataset is the definitive set of statistical area 1 (SA1) boundaries concorded to higher geographies for 2021. This version contains 29,910 SA1s including 16 with empty or null geometries (non-digitised SA1s).
This generalised version has been simplified for rapid drawing and is designed for thematic or web mapping purposes.
SA1 is an output geography that allows the release of more detailed information about population characteristics than is available at the meshblock level. Built by joining meshblocks, SA1s have an ideal size range of 100–200 residents, and a maximum population of about 500. This is to minimise suppression of population data in multivariate statistics tables.
This SA1 higher geographies 2021 file is a correspondence, or concordance, which relates SA1s to larger geographic areas or 'higher geographies'.
The higher geographies contained in this concordance are: regional council (REGC2021), statistical area 2 (SA22021), territorial authority (TA2021), urban rural (UR2021), and urban rural indicator (IUR2021).
The following geographies were introduced in 2018: statistical area 1 (SA1), statistical area 2 (SA2), urban rural (UR), and urban rural indicator (IUR) as part of the Statistical Standard for Geographic Areas 2018 (SSGA18) which replaced the 1992 New Zealand Standard Areas Classification (NZSAC92).
The geography urban accessibility indicator (IUA) was first published in 2020 and added to this concordance in 2021.
Higher geography names are provided with and without tohutō/macrons, as applicable. Column names for those without macrons are suffixed ‘ascii’.
For further information on individual higher geographies, refer to their metadata.
Digital boundary data became freely available on 1 July 2007.
SA1s are based on the meshblock pattern. Non-alignment of meshblock to cadastral boundaries is one of a number of reasons for meshblock boundary adjustments. Other reasons include requests from local authorities, Local Government Commission, Electoral Representation Commission, and to make census enumeration processes easier. From the meshblock pattern, higher geographies, including the 2021 SA1 pattern, were dissolved using the dissolve tool in the Arc GIS suite.
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