Digital Boundaries are electronic files of the various geographic boundaries (in digitised form) for use in mapping and geographic information systems (GIS). Meshblock boundaries, and boundaries of larger areas, are available digitally at two accuracy levels:
- Annual pattern (level 1) boundaries are the most accurate, containing all of the points digitised along the boundaries. These are generally used when a very high level of accuracy is important. Level 1 boundaries are as at 1 January of the year and are updated and made available annually.
- Census-based (level 2) boundaries have been generalised using a 20-metre tunnel width (all points rounded to one metre) to reduce the number of points along the boundaries, and reduce the size of the dataset. Level 2 boundaries are the accepted standard for general mapping in statistics.
Digital Boundary examples
The following images illustrate two of the main digital boundary layers:
Level 2 area unit boundaries
In the image below, level 2 area unit boundaries (the green shading) are shown for Queenstown Lakes District with meshblocks overlaid (the red lines). The rural meshblocks are identified by the red lines.
Level 2 meshblock boundaries
The image below is an aerial photograph* of the Wanaka area unit, and the 2006 level 2 meshblocks (red lines) have been overlaid. Urban meshblocks and the meshblock numbers can be seen here.
(*Sourced from Aerial photography. F40.Wanaka (2002/03). Crown Copyright Reserved)
2006 Census Meshblock Dataset
Digital Boundaries can be integrated with the 2006 Census Meshlock Dataset using geographic information systems to assist with visualisation, spatial analysis and decision making.
The dataset contains counts starting at the meshblock level for selected variables from the 2006, 2001 and 1996 Census of Population and Dwellings, rebased to the 2006 boundaries. The dataset also contains counts for area units, wards, territorial authorities and regional council areas.
Level 2 area units with 2006 Census data overlaid
In the image below, data from the 2006 Census of Population and Dwellings has been overlaid at area unit level to show at a glance the number of people usually resident in the highlighted area units.
