New pilot datasets for river names
We’re pleased to release two new pilot datasets — NZ River Name Lines and NZ River Name Polygons.
This pilot will help us to understand the benefit of combining river names and location, and they’re now available on the LINZ Data Service:
These are the first openly available rivers datasets providing full coverage of mainland New Zealand with names attributed to river geometries.
How this data can be used
- search for a named river and find its extent
- identify the closest river to a given location
- extract and analyse the geometry of a named river
- create digital cartographic products showing river names
- create digital cartographic products symbolising named and unnamed features differently as a basic hierarchy of importance
- analyse other features against named rivers (e.g. proximity of building outlines)
How centrelines were named
The new NZ River Name Lines (Pilot) dataset consists of features combined from three separate Topo50 datasets — NZ River Centrelines, NZ Canal Centrelines and NZ Drain Centrelines.
All of the features in these three datasets have been included. Unnamed features have an empty name attribute but are still included for context.
Names have been applied using these two processes:
1. Named river geometry matched to the NZ Gazetteer
River names were aligned to match the extents in the New Zealand Gazetteer of Place Names (NZ Gazetteer) where an official name exists.
2. Named river geometry defined by Topo50 geographic name location
For all remaining rivers that have a recorded name on Topo50 maps, the geographic name (related to cartographic text placement) was applied to the nearest centreline.
From here, names were attributed on all geometries downstream to the point the river met a confluence with another named river, or the coast. Names were attributed to the longest reach out of the upstream geometries. This methodology provides an approximation and should not be taken as official.
How polygons were named
The new NZ River Name Polygons (Pilot) dataset consists of features combined from two separate Topo50 datasets — NZ River Polygons and NZ Canal Polygons.
All of the features in these two datasets have been included. Unnamed features have an empty name attribute but are still included for context.
River polygon junctions needed to be split in order to attribute the correct name to the correct water feature. This piece of work was completed in preparation for naming and the resulting geometry changes have already been published in the Topo50 NZ River Polygons dataset.
The same naming methodology used for river centrelines was then used for river polygons.
Important related datasets for visualisation
To get a full picture of water features, you’ll need additional Topo50 datasets — lagoons, lakes, swamps and ponds are not part of these new named datasets.
Further information on these related datasets is in our data dictionary.
Disclaimers
All of the geometries in these pilot datasets are derived from Topo50 datasets as at December 2018 and are unlikely to be updated as part of this pilot. Names align to the NZ Gazetteer at the same date.
Official geographic names as listed in the NZ Gazetteer must be used in all official documents as per the New Zealand Geographic Board (Ngā Pou Taunaha o Aotearoa) Act 2008.
Finally
We’re keen to hear your feedback, which will help shape future rivers datasets. A short online survey is available here, or you can contact us via topography@linz.govt.nz.
For additional technical detail, see the NZ River Names Data Dictionary.
These datasets are available for free under a Creative Commons Attribution 4.0 International license.
Download or connect to the NZ River Name Lines (Pilot) here and the NZ River Name Polygons (Pilot) here.
