deprecate/map UNCEFACT geospatial stuff in favor of OGC GeoSPARQL

[VladimirAlexiev]

(Continuing https://github.com/uncefact/vocab/issues/5#issuecomment-1026404130)

OGC is a stronger authority on geographic information than UNCEFACT, so it would be better to defer to OGC GeoSPARQL classes and props

• to put it bluntly, UNCEFACT has no longer any business regulating geospatial data
• to put it constructively:
  • semantic repos have special indexes, functions and magic predicates to handle GeoSPARQL. In particular asWKT and asGML serializations, region algebras (3 of them) and coordinate system transformations
  • web apps often use GeoJSON.
  • There was no good way to capture GeoJSON in JSONLD (no nested arrays in JSONLD)
  • Now I think one could use @type:@json to capture GeoJSON opaquely in RDF (but semantic repos won't index it)
  • In any case, it's clear how to convert GeoSPARQL serializations from/to GeoJSON and there are many tools

What are all of the UNCEFACT classes and props related to geospatial?

uncefact:Circle , uncefact:GeographicalMultiCurve , uncefact:GeographicalPoint , uncefact:GeographicalMultiSurface , uncefact:GeographicalGrid , uncefact:GeographicalMultiPoint , uncefact:Polygon , uncefact:LinearRing , uncefact:GeographicalLine , uncefact:GeographicalSurface

Props?

[VladimirAlexiev]

As @nissimsan says, we can only deprecate not delete, eg

uncefact:Circle a rdfs:Class; owl:deprecated true;
  skos:scopeNote "Deprecated in favor of OGC GeoSPARQL geometries".

We should also map, eg

uncefact:Polygon a rdfs:Class; owl:deprecated true;
  skos:scopeNote "Deprecated in favor of OGC GeoSPARQL geometries";
  dct:isReplacedBy sf:Polygon.

The new draft spec is https://opengeospatial.github.io/ogc-geosparql/geosparql11/spec.html and adds serializations GeoJSON, KML, DGGS but it will be some time before implementations pick up.

@nicholascar, @dr-shorthair could you review my prev comments and help with mapping?

[nissimsan]

@VladimirAlexiev, we are discussing this on the call now. It is not the role of this project to interfere with the semantics. However, the two actions we will take are:

• List equivalence vocabularies for overlapping areas.
• Pass back this recommendation to UN modelling teams suggesting removal of this part of the BSP model.

[onthebreeze]

This is an issue for the UNCEFACT business domains / vocabulary management. I suggest y

• we start a list of alternative vocabularies (eg schema.org) - not stating preference just listing them
• we feeedback to the business domain that we suggest they may like to deprecate the UN geospatial vocabulary in favour of another.

[nicholascar]

Please note that GeoSPARQL 1.1 now contains a better explanation of the Simple Features geometry types classes (https://opengeospatial.github.io/ogc-geosparql/geosparql11/spec.html#_geometry_class_hierarchy) and an annex listing alignments with other ontologies (https://opengeospatial.github.io/ogc-geosparql/geosparql11/spec.html#_annex_e_alignments_informative).

For the classes listed above, I suspect these mapping might be useful:

UNCEFACT Class	Mapping	GeoSPARQL Simple Features Class
uncefact:Polygon	owl:equivalentClass	sf:Polygon
uncefact:LinearRing	owl:equivalentClass	sf:LinearRing

Assuming that there is nothing really different between a 'Point' and a 'GeographicalPoint' (I don't know UNCEFACT) then:

UNCEFACT Class	Mapping	GeoSPARQL Simple Features Class
uncefact:GeographicalPoint	owl:equivalentClass	sf:Point
uncefact:GeographicalMultiPoint	owl:equivalentClass	sf:MultiPoint
uncefact:GeographicalLine	owl:equivalentClass	sf:Line
uncefact:GeographicalMultiCurve	owl:equivalentClass	sf:MultiCurve
uncefact:GeographicalSurface	owl:equivalentClass	sf:Surface
uncefact:GeographicalMultiSurface	owl:equivalentClass	sf:MultiSurface

I can find no mappings for the following

UNCEFACT Class	Mapping	GeoSPARQL Simple Features Class
uncefact:GeographicalGrid
uncefact:Circle

*NOTE:** having SF classes in GeoSPARQL doesn't do anything for you. GeoSPARQL functions operate on geometry literals, not RDF classes, so, if you want to calculate intersections with a GeoSPARQL engine, you need to make polygon, point etc literals like this:

:feature-x
    geo:hasGeometry [
        geo:asWKT "POLYGON ((...))"^^geo:wktLiteral ;
   ] ;
.

:feature-y
    geo:hasGeometry [
        geo:asWKT "POINT (...)"^^geo:wktLiteral ;
   ] ;
.

WKT, GML etc.

[nissimsan]

@nicholascar, awesome! This is a great format for this NDR section. I love it - thank you!

[nissimsan]

@nicholascar , I added a section about this now. https://github.com/uncefact/vocab/pull/75