General overview on topographic data.
Where can I find information on the topographic data?
Information can be found on the Topo50 and Topo250 web pages.
Are the roads and tracks in the topographic data indicative of public right of access?
No. Representation in the topographic data of a road or track does not necessarily indicate public right of access. Topographic data and maps are designed to show only the physical features (ie not legal) on the land. This includes both private and public roads.
How can I tell if the topographic data is current?
Update histories are provided for Topo50 and Topo250 map sheets.
LINZ welcomes feedback about areas that have changed. Email email@example.com.
How accurate is the topographic data?
For the Topo50 data, 90% of well-defined topographic features have a planimetric (x,y) accuracy of +/- 22 metres and a vertical (z) accuracy of within +/-10 metres. Over the last few years LINZ data maintenance has been undertaken using imagery with accuracy in the order of +/- 6 metres. This means that sheets maintained from this imagery will be a lot better than 22 metres, however +/-22 metres is LINZ's official spatial accuracy.
For the Topo250 data, 90% of well-defined topographic features have a planimetric (x,y) accuracy of +/- 150 metres and a vertical (z) accuracy of within +/- 50 metres.
Why is there a difference between the topographic data and what I can see on other aerial imagery I have?
There could be a number of reasons for this. The most likely is that the data on the map has been updated either before or after the image. Visit Topo50 and Topo250 to see update histories.
If the differences are small, then it could be the result of the generalisation techniques used when capturing the data. At 1:50,000 scale, not all features can be shown (eg, if there is a group of 5 or 6 buildings in close proximity, only 2 or 3 may be shown). Also, where features are very close together (eg, a road, railway line and coastline) they may be separated slightly to enable each to be clearly visible on the printed map.
Why isn't the road in the topographic data in the same place as the road parcel in the cadastre?
The road on the Topo50 map and data represents the physical feature; the cadastral road parcel has commonly been created to enable the location of official road names. Usually roads are built within the cadastral parcel, but not always. In some cases, where the difference is small, it may be attributable to the accuracy of either the cadastral or topographic mapping. Refer to How accurate is the topographic data?
How do I combine individual map sheets from the topo map series?
There are various ways you can do this.
Select the required area in LDS using the cropping feature and download the composite map image. Use a GIS application such as QGIS, or an image editor programme such as Photoshop or Gimp to combine the sheets into one file for printing. Depending on the size you require, you could take it to a local print shop for printing.
Alternatively, you could download each map sheet using the Map Chooser, selecting the geotiff files as they exclude the legend, print them out and manually tape them together.