[Imports] Importing CanVec better?

[Paul Norman]

> From: Maury Markowitz [mailto:maury.markowitz at gmail.com]
> Sent: Monday, October 15, 2012 1:28 PM
> To: imports at openstreetmap.org
> Subject: [Imports] Importing CanVec better?
> 
> Newb here, so I hope this is the right place to ask. I also posted on
> one of the wiki talk pages, but I didn't know if anyone goes there.
> 
> I have noticed that vectors imported from the CanVec database are split
> at grid boundaries. This means that large objects like roads or lakes
> are split into multiple parts in OSM.
> 
> I strongly suspect that there is a way to re-integrate these into single
> objects, which would greatly improve things (case in point, the cottage
> would no longer be on a three-part lake :-)

There are five different types of ways that can be split a tile boundaries.

1. Unclosed ways, like roads. It doesn't matter if these are split, but the
ends need to share nodes so that they're connected. Splitting a road doesn't
change the meaning.

2. Small closed ways, like buildings. These need to be joined into one
closed way.

3. Lakes. These should be joined together, either as a closed way or as a
multipolygon.

4. Large forests. These do not need to be joined. In fact, they need to be
split at some point to avoid having a multipolygon the size of BC.

5. Coastlines (and the coast of lakes like the great lakes). In principle
these are the same as other unclosed ways, but these should only be imported
with those very familiar with both the CanVec water model and OSM
coastlines.

> As this data is automatically imported, is this the right place to
> discuss this?

CanVec isn't automatically imported. If people aren't performing the basic
checks at edges you can send them a note or ask someone else to.