Change history (RDF)

The W3C ORG RDF change-history output of Pipeline A: what each per-snapshot delta.ttl / .nt / .jsonld file contains, why it exists, and how it differs from the GeoJSON data product.

Author

Manuel Balmeo

This dataset publishes two data products. The Boundaries (GeoJSON) section covers the spatial polygons; this section covers the linked-data change history — the output of Pipeline A.

What the RDF is

For every PSGC snapshot, Pipeline A emits a delta (delta.ttl / delta.nt / delta.jsonld) describing how Philippine administrative units changed relative to the previous snapshot: created, deleted, renamed, merged, split, transferred, reclassified, or re-coded. The deltas are serialized on the W3C ORG ontology with PROV provenance and Dublin Core terms.

Why it exists

PSGC codes are not stable: barangays are continually created, merged, split, renamed, transferred between parents, and re-coded. The RDF deltas let a downstream system track an entity’s identity across quarters via the 9-digit correspondence code (see PSGC code structure) and answer questions like “what happened to barangay X between 2023 and 2024?”.

What a delta file contains

A walkthrough of 2023-10-24/delta.ttl, the delta for the 2023-10-24 snapshot. It carries three kinds of resources:

Change events (psgc:event/{date}/{seq}) — typed org:ChangeEvent. Each carries the snapshot date (dct:date), a one-line human description (dct:description), the change type (org:classification → psgc:concept/change-type/{type}), and the entities involved via org:originalOrganization (entity removed/renamed-from) and/or org:resultingOrganization (entity created/renamed-to). For example, a code change:

<https://psgc.gov.ph/event/2023-10-24/0082> a org:ChangeEvent ;
    dct:date "2023-10-24"^^xsd:date ;
    dct:description "PSGC code changed from 1380300033 to 1381500036"@en ;
    org:classification <https://psgc.gov.ph/concept/change-type/code_change> ;
    org:originalOrganization <https://psgc.gov.ph/entity/1380300033> ;
    org:resultingOrganization <https://psgc.gov.ph/entity/1381500036> .

A creation carries only org:resultingOrganization; a deletion carries only org:originalOrganization.

Entities (psgc:entity/{code}) — the units touched by the delta. The 10-digit PSGC code and the 9-digit correspondence code (identity that survives re-codings) are both recorded on org:identifier, the name on skos:prefLabel, and population on schema:population:

<https://psgc.gov.ph/entity/1381500036> a org:OrganizationalUnit ;
    dct:date "2023-10-24"^^xsd:date ;
    schema1:population 15103 ;
    skos:prefLabel "Rizal"@en ;
    org:classification <https://psgc.gov.ph/concept/geographic-level/Bgy>,
        <https://psgc.gov.ph/concept/urban-rural/U> ;
    org:identifier "137602033"^^xsd:string,
        "1381500036"^^xsd:string,
        "137602033"^^psgc:correspondence-code .

Concepts (psgc:concept/{scheme}/{value}) — skos:Concept nodes for the controlled vocabularies used in the delta: change-type/ (creation, deletion, code_change, …), geographic-level/ (Bgy, Mun, …) and urban-rural/ (Urban/Rural), some with skos:prefLabel labels.

This snapshot’s 92 events break down as 29 creations, 55 deletions, and 11 code changes — a single quarter’s worth of barangay creation/deletion/re-coding events.