This dataset is the definitive set of area unit boundaries for 2015 as defined by Statistics New Zealand.
Area units are aggregations of adjacent meshblocks with coterminous boundaries to form a single unbroken surface area (land and/or water). Exceptions to this rule are some area units comprising collections of geographically related inlets and marinas. Area units are non-administrative areas intermediate in size between meshblocks and territorial authorities. In an urban location, an area unit is often a collection of city blocks, while in rural situations area units may be equated to localities or communities. Area units must either define or aggregate to define urban areas, rural centres, statistical areas, territorial authorities, and regional councils. Each area unit must be a single geographic entity with a unique name.
The area unit pattern is revised once every five years in the year immediately before a Census of Population and Dwellings. There may also be changes in other years, in conjunction with local body boundary changes. Statistics New Zealand maintains a concordance file to ensure boundaries relating to earlier area unit patterns can also be generated.
The following table lists the total number of area units by year:
Area unit totals
Digital boundary data became freely available on 1 July 2007.
Area units are based on the meshblock pattern.
Non-alignment of meshblock and cadastral boundaries are 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 of Population and Dwellings enumeration processes easier.
From the meshblock pattern, higher geographies, including the 2015 area unit pattern, were dissolved using the dissolve tool in the Arc GIS suite.
To derive the area unit boundaries clipped to the coastline, meshblock polygons were dissolved to exclude meshblocks with a land/water attribute of Inlet or Oceanic.