[NUUG kart] [Imports] N50 imports from Kartverket (The Norwegian Mapping Authority)

Tor torsm.news at gmail.com
Sun Jun 22 14:47:27 CEST 2014

22. juni 2014 kl. 13:43 skrev Christoph Hormann <chris_hormann at gmx.de>:

> - the source tag should probably go into the the changeset and not be 
> applied to the individual features unless it varies.

Yes, I agree. I think that is tidier. Source tags on the features are
only partially true if somebody edits the features afterwards.

> - the source:date tag is misleading since it specifies the date of the 
> import and not the date of the source itself.

I was thinking about it as the day the data was downloaded from Kartverket.

> If there is some date 
> information in the source data it might make sense to maintain it

There is, at least for some of the features, but I don’t think those
dates are very useful for OSM.

> but the import date is easily visible from the change set.

I agree, if the source:date refers to the date of the import, it is
redundant information.

> - The splitting of the natural=wood polygons at arbitrary straight lines 
> is not a good idea.  I know the Canvec import kind of set a precendent 
> here by doing such splits almost universally but this is really a 
> nightmare in terms of data maintainence.  If the polygons get too large 
> they can be split at natural boundaries like rivers, roads etc.  
> Merging touching polygons with identical attributes should be 
> relatively easy with OGR before conversion to OSM.

As far as I know, they are split that way in the SOSI files from Kartverket.
I agree that it’s best to merge them. I have no idea about how to do that 
with OGR though.

> - there are coastline ways tagged place=islet without being a closed 
> loop.

I know. I forgot to mention that.

> - except for the incorrect direction there are some peculiarities about 
> the waterways - like unconnected closed loops tagged waterway=stream.  
> Looks like either the source data is really quite a mess here or there 
> are some conversion errors.

I guess these are either what I referred to as “streams and rivers
running on top of the ways in waterway=riverbank polygons” or
islands/islets in a larger river. Anyway, they would need to be fixed
before import.

> - there do not seem to be any names of lakes, rivers, islands etc. - are 
> there none in the soure data?

Not in the N50 Arealdekke dataset as far as I know. The names are in a
separate N50 dataset. It has been discussed on the Norwegian mailing
list, and people agreed that it would be better to import names from
the original source, the place name register (sentralt stadnamnregister,


More information about the kart mailing list