[OSM-talk] administrative boundaries and is_in

Thomas Wood grand.edgemaster at gmail.com
Thu Jan 10 19:22:59 GMT 2008


On Jan 10, 2008 6:34 PM, Lukasz Stelmach <stlman at poczta.fm> wrote:
> Robin Paulson wrote:
> > can someone explain a few things about the way boundaries work, and
> > their relation to the is_in key?
> >
> > as far as i can tell, when a location (say the suburb of balham, in
> > london) is added to the map, the is_in tag needs to be set, multiple
> > times. in this case, it would be set as follows:
> >
> > is_in:Westminster (...i think)
> > is_in:greater london
> > is_in:england
> > is_in:united_kingdom
> > is_in:British_Isles
> > is_in:Great_Britain
> > is_in:Europe
> > ...etc.
> >
> > which seems counter-intuitive, not to mention requiring huge amounts
> > of work. do we set this for every item - roads, churches,
> > supermarkets,....thousands of other items?
>
> What I do is putting is_in only on places and I do it rather like
> this: Westminster,greater london,england,united_kingdom,etc. Even
> when I map a few villages in an areay JOSM autocompletes that.
>

My view on this is that relation support should be quickly improved in
the editors.
Relations will add more structure to the current mess of the freeform is_in tag.

>
> > my second, related, point concerns boundaries that coincide with
> > coastlines: do we need to trace over the coastline of a
> > country/city/suburb to define an unbroken loop for each administrative
> > areas,
>
> After reading
> http://wiki.openstreetmap.org/index.php/Key:boundary
> http://wiki.openstreetmap.org/index.php/Talk:Key:boundary#Expanded_usage
> I would not bother.
>
> What is more important to me, and this is question for all who know,
> how to cope boundaries *between* two areas, like administrative
> ones? How to cope with boundaries of different administrative
> levels? If a line is a boundary between communes it is also a
> boundry of respective provinces.

Not necessarily - it could be at the moment, or it could not be. There
are examples (in the UK at least) of overlaps.
This issue has been debated in IRC, I cannot remember if the proposal
that was made there has been transferred to the wiki yet.

Unbroken loops are not required, but it is possible to do it in that
fashion. However, the current convention of tagging left-right should
require less effort in the long run.

> Both webpages above seem to be quite vague about it, or at best
> unofficial.

It's not gone through voting, but nothing is really 'official', the
page could probably do with a little tidying though.

I'll have a read over the whole topic again later and see if I can
bring up any points not yet mentioned.

-- 
Regards,
Thomas Wood
(Edgemaster)




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