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Basemaps in Aotearoa

· 12 min read
Duane Wilkins

Basemaps are the background layers that help you read your data in context. In Māori GIS work they often sit behind decisions about whenua, taiao, access, planning and change over time. They can also carry risk because high-detail imagery can reveal more than you intended to share.

A basemap is not simply a technical background. It quietly tells the reader what the map considers normal and important. A road map puts roads first. A cadastral background makes parcel boundaries feel fundamental. A satellite image privileges what can be seen from above. None of these is necessarily wrong, but the choice affects how the whenua is read. A kaupapa concerned with awa, maunga, historic occupation or taiao may need a very different background from a property or infrastructure map.

This post covers the main basemap options used in Aotearoa, how WMTS tiles work, how imagery is updated and how to add these basemaps into QGIS, ArcGIS Online and other tools.

note

A basemap is context, not truth. It helps you see patterns and locate features, but it is not a legal boundary and it is not always perfectly aligned everywhere. It is also not the whenua itself. It is one representation chosen for a particular purpose.

The main basemap options in Aotearoa​

LINZ Basemaps​

LINZ Basemaps is the main public source for national imagery basemaps and LINZ topographic vector tiles. It is built to work in GIS tools and web maps, and it supports both NZTM2000 and Web Mercator for imagery.

Common Māori GIS uses, especially outside cities, include orienting rural whenua blocks when cadastral lines do not match visible features, understanding catchments, wetlands, slips, river change and coastal movement, supporting whenua and taiao discussions with marae, trustees, kaitiaki and whānau, and checking land-cover change with historical imagery layers.

Start here:

The imagery is extremely useful, but it should remain a supporting layer. A sharp contemporary photograph does not automatically outrank local knowledge, historical evidence or an older map simply because it is more detailed.

Esri basemaps in ArcGIS Online​

ArcGIS Online includes Esri global basemaps such as imagery, streets, terrain and dark canvas. In Aotearoa you will also often see local “NZ Imagery” style basemaps published for the ArcGIS platform.

Two practical points matter. Web maps usually default to Web Mercator (EPSG:3857). If you are doing measurement, digitising or analysis, keep the working projection in NZTM2000 (EPSG:2193) where appropriate and let the basemap reproject as background.

Eagle Technology “NZ Imagery” basemaps for ArcGIS​

Eagle Technology publishes “NZ Imagery” basemaps for the ArcGIS platform using the best available publicly owned imagery. These are commonly used by councils and ArcGIS organisations that want an Aotearoa-focused basemap set.

Useful starting points:

Council imagery services​

Many councils publish aerial imagery, sometimes many years of it, through public map viewers or open-data portals. Auckland Council is a strong example, with public access to multiple historical aerial-photography services through GeoMaps.

Examples:

Council imagery can be particularly useful around rural fringe areas, harbours, coastal margins and local projects where LINZ imagery may be older or lower resolution.

tip

If you can see an imagery layer clearly in a council web viewer, it is often being served as WMTS, WMS, XYZ tiles or an ArcGIS REST service. In many cases you can add the same service to your own GIS project if the terms of use allow it.

The basemap shapes the story​

It is worth pausing before choosing the most detailed background available. A basemap establishes visual hierarchy before any of your own layers are added. If the background is dominated by property parcels, the map can make whenua appear first and foremost as property. If it is dominated by roads and towns, movement through the state transport network becomes visually primary. A terrain or hydrographic background may make awa, ridgelines and catchments much easier to understand.

For Māori GIS, the question should therefore be more than “Which basemap looks best?” Ask what the kaupapa is, what relationships to place need to remain visible, what information the audience actually needs and what the background might unintentionally imply. Sometimes a simpler basemap is the stronger choice because it leaves space for the story held in the project itself.

How LINZ imagery flows into other basemaps​

LINZ coordinates and publishes a large amount of publicly owned aerial and satellite imagery. LINZ Basemaps serves that imagery as fast map tiles. Eagle Technology’s ArcGIS basemap layers also draw on publicly owned imagery and commonly reference LINZ as a key source.

In practice, LINZ is a primary source for national imagery coverage, LINZ Basemaps is the most direct way to use that coverage in GIS tools, and ArcGIS users often encounter similar imagery through Eagle Technology “NZ Imagery” items or LINZ-published ArcGIS items.

Keeping the source visible matters. When imagery is republished through another platform, it can become easy to forget who captured it, when it was flown and what licence or limitations apply. Provenance should travel with the basemap just as it should with any other layer.

How WMTS tiles work​

WMTS is a map-tiling standard. Instead of downloading one huge image, your GIS application requests many small images called tiles. Each tile represents a fixed area at a fixed zoom level. A tile grid is defined by a tile matrix set, your application requests tiles by zoom and coordinates, and cached tiles allow the same areas to load quickly for many users.

LINZ Basemaps imagery supports two common tile matrix sets:

  • Web Mercator (EPSG:3857), typical for web maps
  • NZTM2000 (EPSG:2193), very useful for New Zealand GIS work

LINZ Basemaps technical information:

caution

Tiles are made for fast display, not for high-precision digitising. If you are drawing boundaries that matter, use the appropriate cadastral, surveyed, legal or locally authorised source for the question and treat imagery as supporting evidence only.

How often imagery is updated​

Aotearoa does not get re-flown as one single national update. Imagery is updated region by region and project by project, and the “best available” layer is often a mosaic of different surveys and dates. One rohe may have new rural imagery this year while another is still using an older flying season. Urban areas are often updated more frequently than remote rural areas, and different resolutions can sit side by side.

Examples include:

To check dates for your area, open LINZ Basemaps, search for your region or a year, turn layers on and off, and then open the matching dataset in LINZ Data Service if you need the deeper metadata.

Knowing the date matters because the landscape in a basemap may not be the landscape people are dealing with now. A river may have moved after a flood, a forestry block may have been harvested, a road may have changed or a coastal edge may have retreated. The image is a dated observation, not a permanent description of the whenua.

When satellite imagery is used​

Where high-resolution aerial imagery is not available, LINZ Basemaps can use satellite imagery to provide coverage.

Examples:

Satellite imagery is often a cloud-managed mosaic across a time window, so the date can be a range rather than one capture day.

Why terrain affects imagery alignment​

Even when imagery is orthorectified, rugged terrain can still create visible issues. Steep hill country, cliffs and gullies can cause local shifts. Tall vegetation and buildings can lean slightly. Seamlines can be obvious where different flights meet, and shadows can hide fence lines, tracks and small waterways.

Rural Aotearoa is a good test case because ridgelines, bush margins, slips and braided riverbeds can look quite different between dates and surveys. Where interpretation is uncertain, say so clearly. Technical precision should not be used to manufacture certainty that the source does not support.

Practical ways to reduce problems include using a recent DEM or LiDAR hillshade to understand landform, cross-checking with the appropriate cadastral, road or hydrology sources, comparing multiple imagery dates, and asking people who know the whenua to review interpretations that depend on local features.

Historical imagery basemaps​

Historical imagery is often where Māori GIS becomes particularly powerful because it can make land-cover change, coastline movement, river modification, forestry history, settlement patterns and wāhi tūpuna context visible across time.

LINZ Basemaps includes scanned historical imagery layers split around 31 December 1989:

For broader discovery of older photo frames and metadata, LINZ also publishes historical footprints:

note

Older imagery can be soft, greyscale or less spatially precise. It can still be extremely useful for patterns and change, especially when used alongside kōrero, whānau memory, local knowledge and other historical evidence. The photograph can show what was visible from the air; it cannot on its own explain the relationships or history of the place.

Adding these basemaps to your GIS projects​

QGIS​

You can add LINZ imagery basemaps using WMTS. The simplest approach is to copy a WMTS capabilities URL from LINZ Basemaps and add it as a WMS/WMTS connection in QGIS.

Guides:

LINZ topographic vector tiles can also be added to QGIS using a style JSON endpoint:

Use NZTM2000 (EPSG:2193) for most analysis and editing in mainland Aotearoa where appropriate, and let QGIS reproject web basemaps as background if needed.

ArcGIS Online and ArcGIS Pro​

ArcGIS Online can add LINZ basemaps through published groups or by adding WMTS services directly.

Guides:

If you are using Eagle Technology “NZ Imagery” items, check the item details for terms of use and attribution.

Council imagery and the source problem​

A council viewer can show several historical years of imagery, but the source is not always obvious. Look for an About, Layers or Attribution panel, an ArcGIS item-details link or REST service, the council open-data portal, or a layer name that includes a contractor, year or survey code.

Auckland examples:

caution

Seeing imagery in a public viewer does not always mean you can reuse it anywhere. Check the licence and terms of use before embedding it in your own public maps or publications.

Creating your own local basemap​

Creating a national basemap is a substantial technical job involving storage, processing, caching, rate limiting, attribution and long-term hosting. Creating a local basemap for one valley, catchment, pā site area or coastline section is much more realistic.

Local options include georeferenced aerial photos, drone orthomosaics where capture and use are properly authorised, council imagery where reuse is permitted, and local project imagery created for the kaupapa with clear consent.

A practical workflow is to georeference or orthorectify the imagery using defensible control points, save the result as a GeoTIFF while preserving the original source information, use it in QGIS or ArcGIS for local context, and create MBTiles or another cache if fast offline display is required.

Locally created imagery can strengthen rangatiratanga over the mapping environment because the organisation is not entirely dependent on an outside basemap provider. That does not remove the need for permissions or careful handling. Local control includes responsibility for what is captured, who can see it and how long it is kept.

Choosing a basemap for Māori GIS work​

A useful basemap should serve the kaupapa rather than dominate it. For sensitive places, avoid high-resolution imagery in public maps where that detail is unnecessary. Use topo or terrain backgrounds when they communicate the relationship to whenua more clearly. If imagery is required, clip to the smallest practical extent and control labels and overlays carefully. Record the provenance, date range, licence and limitations of the background.

Also ask what the basemap makes visible and what it makes disappear. Does a road basemap make the transport network look more important than the awa? Does a parcel map make the whenua look like a collection of properties? Would a terrain, catchment or intentionally simple background better support the kōrero?

The basemap is not empty space behind the real information. It participates in the story the map tells. Choose it with the same care as the layers you place on top.