portolan-pipeline
The 12 provinces of the Netherlands, administrative boundaries from the Dutch national spatial data infrastructure PDOK, derived from the Kadaster BRK Bestuurlijke Gebieden. Republished as cloud-native GeoParquet with a PMTiles visualization and categorical, labeled MapLibre styles.
Kadaster, the Dutch cadastral agency, derives the country's administrative division from the cadastral registration and publishes it through PDOK, the national open geodata platform, in an edition established every January when municipal reorganizations take effect. This Collection carries the 12 provinces of the 2026 edition, valid from January 1, 2026. PDOK names the layer as the base of public applications from atlasleefomgeving.nl to the official bathing water site zwemwater.nl.
The geometry checks out against the national statistics office.
Computing ST_Area per province reproduces the official CBS surface
figures to one decimal, Utrecht 1,560.1 square kilometres against the
published 1,560.05.
Agents, AGENTS.md has the CBS join recipe, the Baarle enclave surprise, and the metric CRS consequences.
The data asset is GeoParquet 2.0 with a native geometry type and a covering bbox column, so it needs a GeoPandas built on pyarrow 24 or newer. DuckDB spatial queries the same file in place, see AGENTS.md for those patterns. Paths are relative to this directory, and the same code works against the published URL.
Beside the data sits iso19115.xml, the upstream ISO 19115 metadata
record for BRK Bestuurlijke Gebieden, mirrored on July 31, 2026 from
the Nationaal Georegister
and carried as a metadata-role asset. Catalogs that already maintain
ISO metadata can ship it alongside the STAC this way instead of
abandoning it.
The table has 8 columns in all. The full list with types lives in table:columns on the collection.
identificatie holds the CBS region codes PV20 through PV31, the same
keys every provincial table on
CBS StatLine uses, which connects these 12
polygons to Dutch official statistics on population, income, land use,
and more. Trim the CBS side first, the classic OData API pads its keys
with trailing spaces.
The provinces sum to 41,543 square kilometres while the land surface of the Netherlands is about 33,500. Administrative boundaries divide the Wadden Sea, the IJsselmeer, and the delta waters among provinces, so Fryslân is the largest province by total area and roughly 42 percent water. Rankings and densities computed from these polygons answer the water-inclusive question unless you subtract water first, CBS publishes the land-only figures.
One annual snapshot, valid for January 1, 2026 only, and boundary history needs the matching year's edition, PDOK keeps five. Derived from the cadastre but not a substitute for it, parcel-level legal questions belong to the BRK itself. The Caribbean Netherlands, Bonaire, Sint Eustatius, and Saba, belongs to no province and is not here.
License, CC-BY-4.0. Attribution, Kadaster / PDOK. Providers, Kadaster (producer, licensor), PDOK (processor), Portolan SDI (host). Original source, https://service.pdok.nl/kadaster/brk-bestuurlijke-gebieden/atom/downloads/BestuurlijkeGebieden_2026.gpkg . Features, 12. Cloud-native asset, netherlands-provinces.parquet (GeoParquet 2.0).
