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.
Pete,
Wow!!
This is really neat and immediately valuable stuff you are contributing.
Wow!
Kingsley
- Pete
On Tue, Feb 24, 2009 at 10:30 AM, Christopher St John
<[email protected] <mailto:[email protected]>> 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
------------------------------------------------------------
--
Regards,
Kingsley Idehen Weblog: http://www.openlinksw.com/blog/~kidehen
President & CEO
OpenLink Software Web: http://www.openlinksw.com
