[Talk-ca] Re : Administrative Boundary

[Bégin, Daniel]

Bonjour Pierre,

I agree that Nominatim searches are limited since there is almost no Canadian municipal boundaries in osm database. Here is a GeoBase product that contains Municipal boundaries for some Canadian provinces ...
http://www.geobase.ca/geobase/en/data/admin/muni/description.html

Quebec is not there yet but should be included to the product before next fall.

This GeoBase product is not cut over 50K map sheets, contrary to the Canvec product. However, it is not available in .osm format.

About best practices on creating boundary, I'll leave the Canadian community decide about that. However, the osm wiki says that "there now seems to be a consensus of using the boundary key also on linear ways, with relations used to aggregate these ways if needed." A bit what Paul Norman wrote on this list few days ago. I know that many of the CA/US border segments already use relations with other counties boundary on the US side.

By the way, the Canvec product - Release 10 - will start being generated pretty soon - with linear Municipal boundaries where available :-)

Best regards,
Daniel




________________________________
From: infosbelas-gps at yahoo.fr [mailto:infosbelas-gps at yahoo.fr]
Sent: March 20, 2012 14:38
To: talk-ca
Subject: [Talk-ca] Re : Administrative Boundary

Daniel,

In parallel of of the excellent work you are doing for these imports, I suggest that we pursue the discussion on other aspects since the discussion was going in all directions in 2009-2010.  We must have some reflexions on how to import this data properly.

We now have a very good map of Canada but Nominatim Searches are limited since in general (at least for Quebec) there are no administrative limits other then provinces. I think that we all agree it should be a priority to define these administrative limits and assure that we have efficient Nominatim searches.

This information and existing boundaries (ie. provinces, international boundaries) should be treated carefully to assure that Nominatim searches work properly.  We already lost some shorelines. Lets not loose our borderlines!

One aspect I think of is when a way overlaps existing ways. I dont know if this has been discussed before. When a way describing the limits of a town or a region overlaps other levels (ie. province, international borders), do we keep this way independant or integrate with the other information ? And it would be better I think to keep administrative boundaries information separated from other Canvec file imports.

Pierre Béland

________________________________
De : "Bégin, Daniel" <Daniel.Begin at RNCan-NRCan.gc.ca>
À : "infosbelas-gps at yahoo.fr" <infosbelas-gps at yahoo.fr>; talk-ca <talk-ca at openstreetmap.org>
Envoyé le : Mardi 20 mars 2012 8h11
Objet : RE: [Talk-ca] Re : Administrative Boundary

Pierre,

I do not usually ask the same question several times. As It is the first time I see such a difference between an authoritative content and Osm Wiki, I think it worth the trouble to ask twice before processing the entire country!

So, as Paul and you are saying the Osm Wiki classification is OK and I didn't received any comment from other, I'll proceed as the Wiki says.

Best regards,
Daniel

________________________________
From: infosbelas-gps at yahoo.fr [mailto:infosbelas-gps at yahoo.fr]
Sent: March 19, 2012 22:22
To: talk-ca
Subject: [Talk-ca] Re : Administrative Boundary

The wiki values seems consistent for Quebec and I think that we can avoid to restart this discussion again.

Pierre Béland

________________________________
De : "Bégin, Daniel" <Daniel.Begin at RNCan-NRCan.gc.ca>
Envoyé le : Lundi 19 mars 2012 14h34

In Openstreetmap wiki, the admin_level were set to 5,6 and 8 respectively.
...
If it is a documented consensus, I'll keep the values of the wiki. If not, I'll use the the values from GeoBase.

Comments?

Daniel



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