Request: Standalone contour vector tiles and increased topographic detail in topo basemaps utilising elevation basemap data.

[FinlayWallenHalliwell]

User Story

As as an engineering geologist, I am reliant on council GIS web apps, Google Earth, and LINZ topographic data to undertake desk-studies of sites of interest. Council GIS series are highly variable in their content and quality. Google earth is convenient but has poor quality topographic data. LINZ elevation data is high quality but requires fetching, downloading and processing for visualisation as contours.

The recently published terrain-rgb Elevation basemap provides the data I want, but in this format its utility is limited (i.e. in QGIS or in a mapbox/maplibre web map). To increase the utility of this dataset, I would like it to be integrated into the topographic basemaps, such that contour intervals decrease at higher zoom levels, reflecting the quality of the available topographic data. This would avoid the need for processing of DEM data and would allow the data to be utilised in places where only an xyz basemap can be specified.

As a developer and GIS user, a standalone xyz vector tile service of these contours would be useful in building custom basemaps (e.g. contours over aerial), and would save on-the-fly processing to generate contours from terrain-rgb tiles (e.g. with maplibre-contour)

Acceptance Criteria

• Contours produced down to 1m or less elevation interval based on the national elevation dataset.
• Vector tiles of contours produced with appropriate intervals for each zoom level, balancing visual clutter with topographic detail.
• Contour data is integrated into the Topographic and Topolite basemaps, to show higher topographic detail when zoomed in (e.g. z>17).