[Talk-ca] CanVec natural=land tags and untagged ways

[Bégin, Daniel]

Bonjour Samuel, Adam, and all.
 
The purpose of the island conversion from area into point was to maintain toponyms without having the problem caused by natural=island tag for areas  Your question just make me realised I should have simply removed island areas when there were no toponyms attached to it!
 
I should be able to correct it for the next release.
 
Best regards,
Daniel 
________________________________

From: Samuel Longiaru [mailto:longiaru at shaw.ca] 
Sent: May 18, 2011 11:53
To: Adam Dunn
Cc: talk-ca
Subject: Re: [Talk-ca] CanVec natural=land tags and untagged ways


Adam is correct here in that the natural=land tags I was talking about are on single nodes on islands in lakes.  All have had a way surrounding them tagged as inner.  None of the nodes that I have come across and deleted have had a name tag attached and so didn't seem to be serving any purpose.  The name thing is good to know though and so I will be sure to check to see if any other tag is attached to them before deleting.

Sam  


----Original Message-----
From: Adam Dunn <dunnadam at gmail.com <mailto:Adam%20Dunn%20%3cdunnadam at gmail.com%3e> >
To: Bégin, Daniel <Daniel.Begin at rncan-nrcan.gc.ca <mailto:%3d%3fISO-8859-1%3fQ%3fB%3dE9gin%3d2C%3f%3d%20Daniel%20%3cDaniel.Begin at rncan-nrcan.gc.ca%3e> >
Cc: Samuel Longiaru <longiaru at shaw.ca <mailto:Samuel%20Longiaru%20%3clongiaru at shaw.ca%3e> >, talk-ca <talk-ca at openstreetmap.org <mailto:talk-ca%20%3ctalk-ca at openstreetmap.org%3e> >
Subject: Re: [Talk-ca] CanVec natural=land tags and untagged ways
Date: Wed, 18 May 2011 08:38:48 -0700


The natural=island tag that Daniel is referring to used to be applied
to the way of the island. This is the old way of doing things
(pre-Canvec 7). I think the natural=land tag that Samuel is referring
to is a single node at the centre of the island (Canvec 7).

The natural=land node is there for the purpose of retaining toponymy
(naming). Many islands don't have names and you can just delete the
node, but some of these nodes will have the name of the island, so you
should either keep the node or transfer the name of the island over to
the island's outer way.

For water body relations (not coastal), it is sufficient to have just
a closed inner way polygon; you don't need a natural=land tag (or any
other tags). I'm not that experienced with coastal tagging, but I
think having a way going the correct direction around the island and
tagged as natural=coastline is how to tag an island in the ocean/sea.
One shouldn't need a natural=land in that case either (in fact,
according to the wiki, having natural=land as the sole tag on a costal
island is not the correct way of doing things [1]). The two cases
where natural=land is required is when the island is only a node (too
small to be a way polygon), or when you aren't using relations and
need to have an island way polygon (but this is obsoleted by using
relations).

I thought the tagless "ghost" ways were a byproduct of how JOSM
deletes relations, I didn't know it was part of the Canvec export's
construction. They can be tossed.

Adam

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