W3C home > Mailing lists > Public > public-lod@w3.org > March 2009

Re: GeoNames and Spatial Queries

From: Kingsley Idehen <kidehen@openlinksw.com>
Date: Fri, 06 Mar 2009 10:26:31 -0500
Message-ID: <49B140A7.1040402@openlinksw.com>
To: Peter DeVries <pete.devries@gmail.com>
CC: Christopher St John <ckstjohn@gmail.com>, public-lod@w3.org
Peter DeVries wrote:
> This might not be of specific interest for your specific project, but 
> may be to others ...
> There are climate and biogeographical data sets that have a 1km x 1km 
> resolution.
> Specifically, WorldClim http://www.worldclim.org/
> /"WorldClim is a set of global climate layers (climate grids) with a 
> spatial resolution of a square kilometer."/
> It might make sense to map these to uri's, so they can be easily 
> queried. Also other data can then be tied
> to those uri's. One difference between using something like this and 
> Geonames is the WorldClim data
> set is made up of standard  1km x 1km squares for the entire planet 
> (There may not be records for the areas near
> the poles)
> I have been thinking about doing something like this but it might be 
> better to have a group develop some well
> thought out and widely adopted standard.
> I have been using GeoNames to tie the expected and observed status for 
> species. This allows you to ask
> if a particular species is expected or has been observed in a state 
> our county. I have a specific meaning
> for "Expected" at that is that you would not be completely surprised 
> to collect or observe it. A wild Tiger would be be
> Unexpected for Wisconsin, a wild Cougar would be Expected (although 
> very rare)
> Most of the observation data is not currently publicly available, but 
> you can get some sample observations at:
> http://rdf.geospecies.org/observations/index.rdf
> One thing to note, this particular structure is a little unstable 
> since I have been trying modify it to work better with another
> existing vocabulary. The GeoNames part however, is relatively stable.
> Also the individual species uri's, for those species we know something 
> about, also  give return data on Expected status, currently for 
> Wisconsin and Iowa. (we have little information on Iowa species other 
> than mosquitoes)
> Also, I am open to modifying the structure for observations if anyone 
> has comments or suggestions.


This is really neat and immediately valuable stuff you are contributing.


> - Pete
> On Tue, Feb 24, 2009 at 10:30 AM, Christopher St John 
> <ckstjohn@gmail.com <mailto:ckstjohn@gmail.com>> wrote:
>     I'm looking for feedback/pointers on best practices
>     for finding objects in the Linked Data cloud given
>     a geographic area of interest.
>     Tom Heath's excellent Linked Data tutorial in Austin
>     last week inspired me to do a quick Linked
>     Data-based iPhone application. Think
>     DBpediaMobile[1], only with a very different user
>     interface.
>     I spent some time researching the topic, but I was
>     having a hard time figuring out what the general
>     consensus was (or if there was one yet) I'd be happy
>     to summarize responses into a FAQ answer.
>     The DBpediaMobile paper[2] says:
>      "The map view is built from RDF triples
>      obtained by sending the currently visible area
>      ... to the server, where they are rewritten as
>      a SPARQL query and issued to a Virtuoso server
>      that hosts DBpedia’s geocoordinates..."
>     DBpediaMobile uses GeoNames data, and geonames has
>     an API with a query called "findNearby" that looks
>     promising, but I'm assuming that's "cheating".
>     Calling out to an API breaks the idea of linking
>     within the data, and means that you can't browse
>     through without special integration code.
>     There are proposed extensions to SPARQL to handle
>     spatial semantics[3]. I suspect that would solve the
>     "cheating" issue (because the query would presumably
>     be generic enough to work with any possible data
>     source), but GeoNames doesn't appear to handle any
>     SPARQL at all. (I think)
>     But the excerpt form the paper indicates that the
>     public GeoNames database is not being used. Instead
>     the data has been loaded into a private datastore,
>     presumably one that supports special spatial SPARQL
>     queries?
>     Is that the case? I can always just load up whatever
>     data I need into PostgreSQL (which has excellent
>     geodata support) and drop down into SQL queries, but
>     that seems against the spirit of the thing. And of
>     course at that point it's not really Linked Data at
>     all because it's not on the web, or shared, or RDF.
>     Feedback/hints/obvious-things-I-missed/
>     corrections-to-misapprehensions greatly appreciated.
>     -cks
>     [1] http://wiki.dbpedia.org/DBpediaMobile
>     actually seems to work pretty well on an iPhone,
>     but there's no GPS info and i'd like to see a
>     native app instead of something running in the
>     browser. And what I have in mind has a totally
>     different UI.
>     [2] http://beckr.org/wp-content/uploads/DBpediaMobile.pdf
>     [3]
>     http://data.semanticweb.org/workshop/terra_cognita/2008/paper/main/1/html
>     --
>     Christopher St. John
>     http://praxisbridge.com
> -- 
> ---------------------------------------------------------------
> Pete DeVries
> Department of Entomology
> University of Wisconsin - Madison
> 445 Russell Laboratories
> 1630 Linden Drive
> Madison, WI 53706
> ------------------------------------------------------------



Kingsley Idehen	      Weblog: http://www.openlinksw.com/blog/~kidehen
President & CEO 
OpenLink Software     Web: http://www.openlinksw.com
Received on Friday, 6 March 2009 15:27:06 UTC

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