GeoNames Home | Postal Codes | Download / Webservice | About 

GeoNames Forum
  [Search] Search   [Recent Topics] Recent Topics   [Groups] Back to home page 
[Register] Register / 
[Login] Login 
Geonames for the Semantic Web?  XML
Forum Index -> General
Author Message
bernard



Joined: 18/08/2006 11:54:14
Messages: 30
Offline

Hello all

Has anybody thought about providing geonames information in RDF, since it seems completely ready for migration to the Semantic Web.
Each geoname has an unique that could be easily transformed into a unique URI like http://www.geonames.org#3014258. Maybe there is already something alike in store?

The structure of features codes can easily migrated into some class/subclass structure in an OWL ontology, for example :

<owl:Class rdf:about="http://www.geonames.org/onto#P">
<rdfs:comment xml:lang="en">city, village, ...</rdfs:comment>
<rdfs:subClassOf rdf:resource="http://www.w3.org/2003/01/geo/wgs84_pos#SpatialThing"/>
</owl:Class>

<owl:Class rdf:about="http://www.geonames.org/onto#PPL">
<rdfs:comment xml:lang="en">a city, town, village, or other agglomeration of buildings where people live and work</rdfs:comment>
<rdfs:label xml:lang="en">populated place</rdfs:label>
<rdfs:subClassOf rdf:resource="http://www.geonames.org/onto#P"/>
</owl:Class>

Using the wgs84_pos:SpatialThing class as a generic class allows to use location properties wgs84_pos:lat, wgs84_pos:long and wgs84_pos:alt. Other attributes like population, postal code, wikipedia article, ... can also be easily added as RDF properties.

If there is interest in this, I can provide a full ontology in OWL format, and some instances in RDF. Having RDF data available through geonames Web Services would be very cool indeed (along with the regular XML format).

Thoughts?
bernard



Joined: 18/08/2006 11:54:14
Messages: 30
Offline

Forgot that login into geonames is not login into the forum. I am the anonymous
marc



Joined: 08/12/2005 07:39:47
Messages: 4418
Offline

Hi Bernard

We have tought about creating a RSS namespace for geographic data. GeoRSS unfortunately only supports latitude and longitude which is not sufficient or has the wrong granularity in many cases. If a feed entry is about a country, latitude and longitude of a single point is not appropriate.

Here the current draft :
http://www.geonames.org/geonamesRSS.html


An OWL ontology for geonames is certainly an interesting idea. Do you already have a particular use case in mind?

Regards

Marc

PS: I have assigned your userid to your anonymous posting. Single Sign On for the forum and the geonames application is still on the todo list.

[WWW]
Anonymous



Marc
An OWL ontology for geonames is certainly an interesting idea. Do you already have a particular use case in mind?  

Sorry for the delayed answer. I went through a hard drive crash two weeks ago, then a week of holidays.
In a nutshell, use cases I have in mind include integration of geonames data with other territorial information also available in RDF. I'm currently working on several projects using the later, especially in tourism information. A local ontology of touristic offer could include all or some specific geonames objects, based on their class (such as mountains, rivers, lakes, whatever).
bernard



Joined: 18/08/2006 11:54:14
Messages: 30
Offline

And again, forgot to login for the previous post
marc



Joined: 08/12/2005 07:39:47
Messages: 4418
Offline

Bernard

If there is interest in this, I can provide a full ontology in OWL format, and some instances in RDF. Having RDF data available through geonames Web Services would be very cool indeed (along with the regular XML format).
 


With a concrete project in mind it would be cool to try it. If you can provided the ontology then I will take care of the webservice.

Cheers

Marc

[WWW]
bernard



Joined: 18/08/2006 11:54:14
Messages: 30
Offline

OK Marc. I'll try to find the bandwidth for a first draft in the days to come. We have to agree on the namespace to use for classes and properties. I suggest http://www.geonames.org/ontology#
I have thought about the way to deal with features and codes, and my current idea is to model the feature main categories (letters) as subclasses of "SpatialThing", and subcategories as property values, if they are likely to be extensible and moving. Another idea in such a case is to have feature subcategories organised as a SKOS vocabulary. How stable are feature codes?
marc



Joined: 08/12/2005 07:39:47
Messages: 4418
Offline

Hi Bernard

The namespace http://www.geonames.org/ontology# looks fine in my eyes.
The feature codes should be rather stable. There are now 645 of them, which should be a sufficiently high number not to make many new codes necessary.
There is, however, one issue with feature codes. They are one-dimensional and a feature has exactly one feature code. Sometimes it would make sense for a feature to have more than one code. An example : often a capital of a country is also the capital of an administrative division. In this case the capital should have the two codes PPLC and PPLA rather than only having the code PPLC.
A multi-dimensional, tagging like approach would have more flexibility.

This thread could also be interesting :

http://groups.google.com/group/geonames/browse_frm/thread/6f1a1af74d2120b4/9e9a249f9f06b024#9e9a249f9f06b024

I am really looking forward to your proposal.


Regards
Marc

[WWW]
bernard



Joined: 18/08/2006 11:54:14
Messages: 30
Offline

A first draft of a geonames RDF-OWL ontology is available at
http://perso.orange.fr/universimmedia/geo/geonames_v0.rdf

At the end of the file are some instances. Note that, as explained before, the features are modeled as skos:Concepts. There are only a few examples of them in the file. The whole set of features I can deliver as a separate SKOS file. Using SKOS concepts make it possible to further organise the features in a proper hierarchical thesaurus, if needed.

I recommend browsing the RDF in SWOOP 2.3. with which it was edited. See http://www.mindswap.org/2004/SWOOP/ for download.

Comments waited and welcome.

PS : the model used has no cardinality restriction so far, so a place can have several features. Actually in the ontology the primitive object is a place, and the feature a separate concept. Hence the flexibility
bernard



Joined: 18/08/2006 11:54:14
Messages: 30
Offline

Overnight got some new ideas about it, so it's version 0.1 already
http://perso.orange.fr/universimmedia/geo/geonames_v0.1.rdf
The vocabulary in v0 could be confusing vs geonames current terminology. So I replaced "Place" class, by "Feature", and "fCode" is an object property of "Feature" with range "FeatureCode".
Also replaced "isPartOf" by "parentFeature", but not sure it makes sense. What is the actual relationship now in geonames database between the two avatars of "PACA" region : the feature "Provence Alpes Côte d'Azur" identified by http://www.geonames.org/maps/geonameId=2985244
and the "Provence-Alpes-Côte dʼAzur" subdivision (with some encoding issue, BTW) retrieved by http://ws.geonames.org/countrySubdivision?lat=44&lng=6 ? Same issue with the country France and the feature French Republic.
I'm not sure there is any relationship at all between those. So the hierarchy of features France > PACA > Hautes-Alpes > Embrun I have put in the instances is maybe only a wishful thinking.
I've also got rid of wikipedia links for the moment, since there again the relationship with geonames features is unclear to me. Thought about including a "nearbyWikipedia" property with the default option ...
marc



Joined: 08/12/2005 07:39:47
Messages: 4418
Offline

The feature "Provence Alpes Côte d'Azur" identified by http://www.geonames.org/maps/geonameId=2985244
and the "Provence-Alpes-Côte dʼAzur" subdivision should be one and the same thing. (I say 'should' because there is still some work to do )

The hierarchy is exactly as you describe it, there is even a (undocumented) webservice for this :
http://forum.geonames.org/gforum/posts/list/82.page

I also prefer not to include wikipedia in the ontology at this moment.

PS :
Can you elaborate on the encoding issue? Possibly in an other thread.

[WWW]
bernard



Joined: 18/08/2006 11:54:14
Messages: 30
Offline

See a consolidated proposal at http://perso.orange.fr/universimmedia/geo/geonames_ontology_v1.0.rdf
I have simplified the model : no more subclasses of features, the typing is made using properties "featureClass" and "featureCode", pointing to "Class" and "Code" respectively, which are themselves subclasses of "skos:ConceptScheme" and "skos:Concept" respectively. So all classes and codes are defined in a SKOS vocabulary. This seems closer to the actual data structure and "spirit" of geonames.
All feature codes are included in the ontology file.
I also updated examples accordingly at http://perso.orange.fr/universimmedia/geo/geonames_examples.rdf
Previous versions are not online anymore to avoid confusion.
bernard



Joined: 18/08/2006 11:54:14
Messages: 30
Offline

I'm happy to announce that the geonames ontology is now available where it belongs at http://www.geonames.org/ontology/
And congratulations to Marc who set up the matching RDF Web Service in no time.

NB : The test files at universimmedia are not available any more.
Anonymous



Hello, I'm very happy to see Geonames's support for OWL and RDF. I read through the Geonames ontology, and put together an overview of it. Not sure if my interpretation of the ontology's semantics is all accurate.

link: Geonames ontology in OWL

Comments are welcome.

- Harry Chen
http://geospatialsemanticweb.com
Anonymous



Very cool! Thanks guys. Some appreciation, comments and criticism here:

http://dowhatimean.net/2006/10/news-from-the-frontier-geonames-on-the-semantic-web

http://dowhatimean.net/2006/10/linking-your-geonames-place-from-your-foaf-file

–Richard
bernard



Joined: 18/08/2006 11:54:14
Messages: 30
Offline

Thanks a lot Harry and Richard for review and remarks. See my answers on your respective blogs.
marc



Joined: 08/12/2005 07:39:47
Messages: 4418
Offline

A new version incorporating the feedback from the blogosphere has been deployed today.

Here the Geonames Ontology documentation :

http://www.geonames.org/ontology/

And here today's blog :
http://geonames.wordpress.com/2006/10/21/semantic-web-concept-vs-document/

Thanks to everyone for their feedback and comments.

Marc

[WWW]
 
Forum Index -> General
Go to:   
Powered by JForum 2.1.5 © JForum Team