GeoNames Ontology

The Semantic Web

The Semantic Web is a project that intends to add computer-processable meaning (semantics) to the World Wide Web.

In Feb 2004, the World Wide Web Consortium released the Resource Description Framework (RDF) and the OWL Web Ontology Language (OWL) as W3C Recommendations. RDF is used to represent information and to exchange knowledge in the Web. OWL is used to publish and share sets of terms called ontologies, supporting advanced web search, software agents and knowledge management.

The GeoNames Ontology

The GeoNames Ontology makes it possible to add geospatial semantic information to the World Wide Web. All over 11 million GeoNames toponyms now have a unique URL with a corresponding RDF web service. Other services describe the relation between toponyms.

The ontology for GeoNames is available in OWL: ontology_v3.3.rdf, mappings.

GeoNames is using 303 (See Other) redirection to distinguish the Concept (thing as is) from the Document about it.

For the town Embrun in France we have these two URIs:

The first URI [1] stands for the town in France. You use this URI if you want to refer to the town. The second URI [2] is the document with the information GeoNames has about Embrun. The GeoNames web server is configured to redirect requests for [1] to [2]. The redirection tells Semantic Web agents that Embrun is not residing on the GeoNames server but that GeoNames has information about it instead. See the blog posting about "Concept vs. Document" for more information.

Example

An example RDF description of a GeoNames "Feature" document, as obtained through the RDF webservice at https://sws.geonames.org/3020251/about.rdf:

<rdf:RDF
  xmlns:cc="http://creativecommons.org/ns#"
  xmlns:dcterms="http://purl.org/dc/terms/"
  xmlns:foaf="http://xmlns.com/foaf/0.1/"
  xmlns:gn="https://www.geonames.org/ontology#"
  xmlns:owl="http://www.w3.org/2002/07/owl#"
  xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
  xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
  xmlns:wgs84_pos="http://www.w3.org/2003/01/geo/wgs84_pos#">
<gn:Feature rdf:about="https://sws.geonames.org/3020251/">
  <rdfs:isDefinedBy rdf:resource="https://sws.geonames.org/3020251/about.rdf"/>
  <gn:name>Embrun</gn:name>
  <gn:alternateName xml:lang="oc">Ambrun</gn:alternateName>
  <gn:featureClass rdf:resource="https://www.geonames.org/ontology#P"/>
  <gn:featureCode rdf:resource="https://www.geonames.org/ontology#P.PPL"/>
  <gn:countryCode>FR</gn:countryCode>
  <gn:population>7069</gn:population>
  <gn:postalCode>05200</gn:postalCode>
  <wgs84_pos:lat>44.56387</wgs84_pos:lat>
  <wgs84_pos:long>6.49526</wgs84_pos:long>
  <gn:parentFeature rdf:resource="https://sws.geonames.org/6446638/"/>
  <gn:parentCountry rdf:resource="https://sws.geonames.org/3017382/"/>
  <gn:parentADM1 rdf:resource="https://sws.geonames.org/2985244/"/>
  <gn:parentADM2 rdf:resource="https://sws.geonames.org/3013738/"/>
  <gn:parentADM3 rdf:resource="https://sws.geonames.org/3016701/"/>
  <gn:parentADM4 rdf:resource="https://sws.geonames.org/6446638/"/>
  <gn:nearbyFeatures rdf:resource="https://sws.geonames.org/3020251/nearby.rdf"/>
  <gn:locationMap rdf:resource="https://www.geonames.org/3020251/embrun.html"/>
  <gn:wikipediaArticle rdf:resource="https://en.wikipedia.org/wiki/Embrun%2C_Hautes-Alpes"/>
  <rdfs:seeAlso rdf:resource="http://dbpedia.org/resource/Embrun%2C_Hautes-Alpes"/>
</gn:Feature>
<foaf:Document rdf:about="https://sws.geonames.org/3020251/about.rdf">
  <foaf:primaryTopic rdf:about="https://sws.geonames.org/3020251/"/>
  <cc:license rdf:resource="https://creativecommons.org/licenses/by/3.0/"/>
  <cc:attributionURL rdf:resource="https://sws.geonames.org/3020251/"/>
  <cc:attributionName rdf:datatype="http://www.w3.org/2001/XMLSchema#string">GeoNames</cc:attributionName>
  <dcterms:created rdf:datatype="http://www.w3.org/2001/XMLSchema#date">2006-01-15</dcterms:created>
  <dcterms:modified rdf:datatype="http://www.w3.org/2001/XMLSchema#date">2010-04-19</dcterms:modified>
</foaf:Document>
</rdf:RDF>

Linked Data

The features in the GeoNames Semantic Web are interlinked with each other. Depending on applicability the following documents are available for a feature:

The children (countries for a continent, administrative subdivisions for a country, ...). As an example, the children of France: https://sws.geonames.org/3017382/contains.rdf
The neighbours (neighbouring countries). As an example, the neighbours of France: https://sws.geonames.org/3017382/neighbours.rdf
Nearby features. Nearby to the Eiffel Tower are Champ de Mars, Trocadéro - Palais de Chaillot, ...: https://sws.geonames.org/6254976/nearby.rdf

Entry Points into the GeoNames Semantic Web

There are several ways how you can enter the GeoNames Semantic Web:

start from mother earth and follow the Linked Data links
use the geonames search webservice with the type=rdf parameter option
download the database dump and construct the url for the features using the pattern "http://sws.geonames.org/geonameId/"
RDF dump with 11,985,741 features and about 182 million RDF triples (2020-02-14). The dump has one RDF document per toponym on every line of the file. Note: the file is pretty large — make sure the tool you use to uncompress is able to deal with the size and does not stop after 2GB, an issue that happens with some old (Windows) tool versions.

Contact

Marc Wick (implementation)

More Information

Harry Chen in the Geospatial Semantic Web Blog describes the key concepts of the GeoNames Ontology.
Overview over GeoNames Feature Codes with number of features per code.
More information on Linked Data.

Version History

2021 July, Version 3.3rdf
PPCLH and PPLH of class P (not A) — Peter Kleiweg
2019 November, Version 3.2rdf
Elisa Kendall
2012 November, Version 3.1rdf
Added gn:GeonamesFeature, subclass of gn:Feature. Added explicit property gn:geonamesID, mandatory and unique for each gn:GeonamesFeature instance. Deleted owl:FunctionalProperty declarations for properties attached to gn:Feature, replaced by local cardinality restrictions on gn:GeonamesFeature — so gn:Feature and its properties can be used in the open world for features not necessarily identified in the GeoNames database, or with partial descriptions. Modified equivalent classes and superclasses of geonames:Feature in other vocabularies. Added new feature codes for historical features. Improved metadata.
2012 February, Version 3.0.1rdf
Improved metadata. Changed gn:featureClass and gn:featureCode superproperty from dc:subject to dc:type. Property chain ensuring consistency of feature code and feature class values (OWL 2.0). Indication of new and deprecated feature codes using skos:historyNote. Multilingual labels for codes (Russian, Bulgarian, Swedish and Norwegian). Explicit code values using skos:notation. New types of alternate names (historical, colloquial). Equivalent classes matching feature codes in various ontologies such as schema.org, linkedgeodata.org, dbpedia.org, INSEE ontology are provided in a separate mappings file.
2010 October, Version 2.2.1rdf
Restore name properties, subproperties of skos labels.
2010 September, Version 2.2rdf
Use skos labels, add URIs for parent admin divisions.
2010 June, Version 2.1rdf
Changed inCountry to countryCode. Added metadata for license information.
2007 Apr 02, Version 2.0
Added isOfficialName, locatedIn, relationships with GEMET concepts.
2006 Oct 30, Version 1.2.3
Added labels for name and alternate names.
2006 Oct 25, Version 1.2.2
Cosmetics.
2006 Oct 23, Version 1.2.1
Linked data document with backlink to main feature.
2006 Oct 21, Version 1.2
New URIs with 303 redirect, linked data (contains, neighbours, nearby).
2006 Oct 14, Version 1.0