Historical research
Historical GIS is strongest when every mapped feature remains connected to the document, plan, photograph or record that supports it.
Do not begin by trying to make a complete historical map. Begin with a research question, collect evidence, preserve the source wording, and create geometry only when the geographic evidence is strong enough to justify it.
The research workflow
question
→ source discovery
→ exact source reference and wording
→ candidate place or feature
→ name and geographic checking
→ historical plan/map/imagery evidence
→ location status and uncertainty
→ GIS geometry where justified
→ map or research output
→ source trail and unresolved questions
The Archives to map page explains this workflow in detail. The Historical ingoa wāhi worked example applies it end to end.
Find the right source
| I am looking for... | Start with | Useful supporting evidence |
|---|---|---|
| references in Treaty research | Waitangi Tribunal | CFRT research, plans, Māori Land Court records, Gazette |
| Māori land blocks, partitions or plan evidence | Survey, title and Māori Land Court plans | Pātaka Whenua, cadastral context, historic maps |
| historical place names | Papers Past, DigitalNZ, historic maps | Gazetteer, Gazette notices, plans, local records |
| government files and correspondence | Archives New Zealand | Gazette, plans, Tribunal research |
| formal notices and legal descriptions | New Zealand Gazette | cadastral records, plans, contemporary maps |
| landscape change | Historic maps and NZMS series, Retrolens | current imagery, terrain, survey plans |
| existing commissioned historical research | CFRT research | original source references cited in the research |
No single collection is complete. The strongest geographic conclusion often comes from several independent clues.
1. Keep a research log from the beginning
Use the spatial research log before creating GIS geometry.
At minimum record:
- source/repository
- record or document identifier
- page, sheet or plan
- date
- exact name or wording as it appears
- spatial clue
- possible match
- location status
- evidence note
- next research action
A future researcher should be able to reconstruct the path from the map back to the source.
2. Preserve historical wording
Do not silently replace historical spelling with a modern form.
Keep separate fields for:
name_as_source
matched_name
match_source
match_source_id
name_status
The original wording is evidence. The matched or normalised name is a later interpretation.
3. Treat search results as candidates
OCR, archive search, Local AI and name matching are retrieval tools. A result becomes useful evidence only after the source page or record has been checked.
For large document collections, Local AI can help find candidate references while keeping files on the local computer. Ask it for the passage and page, not a coordinate.
4. Build geography from several clues
Useful geographic clues include:
- Gazetteer records
- historical maps and survey plans
- Māori land block names
- rivers, maunga, roads and settlements named in the same passage
- distances and directions in the text
- legal descriptions
- historic aerial imagery
- repeated references across independent sources
A place can remain unlocated or approximate. GIS does not require every research record to become a point.
5. Georeference only when the source adds evidence
Use Georeferencing historical maps for scanned plans or maps and the Retrolens historical imagery workflow for aerial photography.
Record control points, transformation method and residual/alignment information. Do not use a moving riverbank as a control point if river movement is the subject of the research.
6. Separate evidence from interpretation
A useful research table keeps these ideas apart:
| Field type | Example |
|---|---|
| source evidence | “Te Awa Pā” appears on plan ML 1234, sheet 2 |
| geographic clue | label is north of named stream and beside block boundary |
| interpretation | likely corresponds to this approximate locality |
| location status | supported / approximate / conflicting / unlocated |
| unresolved question | confirm against another plan or local source |
This prevents a neat GIS point from concealing how uncertain the research actually is.
7. Produce a research output, not just a map
Useful outputs include:
- source-linked GeoPackage layer
- research table containing both located and unlocated records
- chronological map
- map of name variants
- historical/current comparison
- journey or route reconstruction
- evidence map for further discussion
- source index for another researcher
The map should remain an index into the evidence rather than becoming the only surviving record of it.
Major sources
- Archives New Zealand Collections search
- Papers Past
- DigitalNZ and the DigitalNZ API
- Historic maps and NZMS series
- New Zealand Gazette notices
- Waitangi Tribunal documents and reports
- Crown Forestry Rental Trust research and mapping
- Survey, title and Māori Land Court plans
- Build a source-linked research log
Continue the workflow
- Archives to map
- Historical ingoa wāhi worked example
- Investigating a historic kāinga
- Māori land data
- Place names and ingoa wāhi
- Provenance and source checking
Last reviewed: 4 September 2026