Investigating land-use change

Use imagery to establish what visibly changed and when, then bring in land-cover/property/environmental data to help explain the pattern.

Sequence

1. define a change class: wetland, forest, urban, quarry, road, plantation, riparian planting
2. obtain the earliest suitable historical aerial
3. obtain one or more intermediate images
4. use current LINZ imagery
5. add Sentinel-2/Landsat where a denser time series helps
6. digitise comparable extents or classify raster data
7. add parcels only for land-administration context
8. add catchment, soil, hazard or planning data according to the question

Control comparison conditions

Season, tide, drought, harvest cycle and image quality can create apparent change. Use Compare imagery over time before calculating area differences.

Report precision honestly

If the 1950 image is poorly aligned, a change area quoted to 0.01 ha is false precision. The uncertainty of the oldest/weaker source limits the result.

Next research step

Once a change period is narrowed, search council records, Gazette notices, newspapers, land records or project reports for the process behind the change.

Last reviewed: 26 August 2026