[Imports] [NUUG kart] kartverket imports to OpenStreetMap

[Christoph Hormann]

On Tuesday 15 October 2013, Tyrfing OSM wrote:
>
> I have recently used N50 from Kartverket as one of my sources for
> manually editing the map, and I was one of the people Norman asked to
> explain (OSM user name Tyrfing).
> I'm not using the data set as source for an automatic/scripted
> import, but as a source from which I manually extract data. I'm
> selective on which objects to extract, and I have the local knowledge
> needed to verify the data.

Hello Tyrfing,

first of all i think it is great you are working on improving waterbody 
mapping in Norway since as you are certainly aware mapping of those is 
very patchy in Norway at the moment.  And using the kartverket data is 
also most certainly a good idea.

> [...]
>
> I don't consider this use of data from Kartverket as an import, but
> as manual editing using an external source, comparable to using e.g.
> Bing as a source. The main difference is that N50 as a source is more
> accurate and faster to work with.

From a quick look at your recent edits it seems they are well made and 
the new data is mostly well merged with existing stuff.  But it is 
unavoidable due to the sheer amount of data you add that there are 
mechanical decisions made in the process that would deserve being 
discussed.  This is what makes your edits different from use of Bing 
imagery as source.  I see for example most waterways are tagged as 
stream although many are obviously too large for that (waterway=stream 
in combination with width=2 for example already stretches the 
definition of stream and there are streams in your edits significantly 
larger).  You also seem to tag all wetlands with wetland=bog but i am 
not sure if this is correct in all cases, especially with wetlands 
around a river.  But i lack the local knowledge to tell if this is 
truely wrong in the individual case.  Again something that would need 
to be discussed if such tag is applied generally to all wetlands and is 
not decided individually.  Finally i saw there are various unconnected 
streams like

http://www.openstreetmap.org/browse/way/240629790
http://www.openstreetmap.org/browse/way/240630383

that are obviously errors and deserve manual checking and fixing.  At 
least they should be tagged with a fixme.

Note a thorough import discussion could also help with your workflow - 
the lack of orientation in the waterways you fix by hand for example 
can probably mostly be corrected automatically for the whole data set 
based on the elevation data sets kartverket also made available.

The wiki page

http://wiki.openstreetmap.org/wiki/No:Kartverket_import

seems to be a good start although it currently lacks the full 
documentation of the source data attributes that would be useful to 
discuss the best translation into OSM tags.

Greetings,

-- 
Christoph Hormann
http://www.imagico.de/