Update REFNIS SKOS thesaurus / municipalities being merged

[barthanssens]

(actually a ticket for vocab-belgif, but mentioning it here for gathering additional comments)

There is a linked open data SKOS thesaurus of Statbel's REFNIS municipality codes. Given that a few municipalities will merge end of 2024 / start of 2025 (https://statbel.fgov.be/nl/over-statbel/methodologie/classificaties/geografie), an update is needed.

Two options:

• create a new thesaurus ("2025") and use skos:exactMatch to map the current URIs to the new URIs (~95% of the municipalities) + skos:broadMatch
• continue to use the current 2019 version, with updated schema:startDate and schema:endDate + owl:deprecated (and dcterms:isReplacedBy) for former (merged) municipalites

[barthanssens]

(I'd go for the second option, since there are no "hierarchical" changes like in 2019)

As Statbel pointed out, there is 1 special case: Antwerp, which will not have a new REFNIS code (since it is being merged with a much smaller municipality), meaning that there could be some ambiguity in "new" Antwerp vs "old" Antwerp if option B is selected (since the URI will be re-used). An owl:version + skos:note could be added to document this change.

[bdevloed]

Thanks for opening this ticket.

I also feel reluctant to keep minting new URI's for the same unchanged NIS code for every NIS release. Wouldn't it be better to keep the year of the release out of the uri? And reflect updates as described in option 2?

Releasing 2025 NIS updates in a 2019 namespace seems a bit counter intuitive.

[barthanssens]

It's a bit of a tradeoff: the reason why there are currently two year-coded version of REFNIS, is mainly because of changes in "hierarchy" (i.e. municipalities were "moved" to another arrondissement = changes in skos:broader). Which AFAIK is non-trivial to keep track of in plain SKOS, if you want to be able to have both old and new situation in one version...

(one could probably use named graphs to group these statements, but not sure if that would make it more clear to other users / would be supported in tools)

[barthanssens]

As an example on how the new relations could be documented

Easiest way (downside, no URI to uniquely identify Antwerp before/after merger, then again, that's also not the case for the '11002' code in non-linked data applications. It is easy to indicate start/end date of a concept, but not the start/end date of a relation without resorting to quads / RDF-star)

<http://vocab.belgif.be/auth/refnis2019/11002> a skos:Concept ;
    skos:prefLabel "Antwerpen"@nl ;
    schema:startDate "1831-01-01" ;
    skos:changeNote "Includes Borsbeek as of 1/2025";
    skos:narrower  <http://vocab.belgif.be/auth/refnis2019/11007> .

<http://vocab.belgif.be/auth/refnis2019/11007> a skos:Concept ;
    skos:prefLabel "Borsbeek"@nl ;
    schema:startDate "1831-01-01" ;
    skos:changeNote "Part of Antwerpen as of 1/2025 " ;
    skos:broader <http://vocab.belgif.be/auth/refnis2019/11002> .

<http://vocab.belgif.be/auth/refnis2019/46029> a skos:Concept ;
   schema:endDate "2024-12-31" ;
   skos:prefLabel "Lokeren"@nl ;
   skos:narrower <http://vocab.belgif.be/auth/refnis2019/46014> ; 
   skos:narrower <http://vocab.belgif.be/auth/refnis2019/44045> .

<http://vocab.belgif.be/auth/refnis2019/46014> a skos:Concept ;
   schema:endDate "2024-12-31" ;
   skos:prefLabel "Lokeren"@nl ;
   skos:broader <http://vocab.belgif.be/auth/refnis2019/46029> .

<http://vocab.belgif.be/auth/refnis2019/44045> a skos:Concept ;
   schema:endDate "2024-12-31" ;
   skos:prefLabel "Moerbeke"@nl ;
   skos:broader <http://vocab.belgif.be/auth/refnis2019/46029> .

Another option would be to introduce a '2025' within the refnis2019 uri just for Antwerp, which could lead to some confusion (and still uses a somewhat indirect way to indicate start/end of relation, using once again start/end on the concept/labe)

<http://vocab.belgif.be/auth/refnis2025/11002> a skos:Concept ;
    skos:prefLabel "Antwerpen"@nl ;
    schema:startDate "2025-01-01" ;
    skos:narrower  <http://vocab.belgif.be/auth/refnis2019/11007> .

<http://vocab.belgif.be/auth/refnis2019/11002> a skos:Concept ;
    skos:prefLabel "Antwerpen"@nl ;
    schema:startDate "1831-01-01" ;
    schema:endDate "2024-12-31" .
    skos:broader <http://vocab.belgif.be/auth/refnis2025/11002> .

<http://vocab.belgif.be/auth/refnis2019/11007> a skos:Concept ;

    skos:prefLabel "Borsbeek"@nl ;
    schema:startDate "1831-01-01" ;
    skos:broader <http://vocab.belgif.be/auth/refnis2025/11002> .