[Talk-ca] Edmonton / Strathcona boundary limits

[Pierre Béland]

James 

This is a hierarchical system were you first define level 6 boundaries. Then you can split level 6 in  many level 8 boundaries.  In such a system, you dont leave holes at the upper level when you only have one child. 

You have examples elsewhere. Paris, France, for example has three relations fort levels 6,7,8.
- level 6 : http://www.openstreetmap.org/browse/relation/71525
- level 7 :  http://www.openstreetmap.org/browse/relation/1641193

- level 8 : http://www.openstreetmap.org/browse/relation/7444 

For the province of Alberta, administrative limits have to be 
established for both level 6 (county) and level 8 (municipalities).

For
 Edmonton, since the county contains only one city, I have duplicated the 
relation. The two Edmonton relations, level 6 and level 8 define the 
same area.
- level=6 http://www.openstreetmap.org/browse/relation/2564500
- level=8 http://www.openstreetmap.org/browse/relation/2563550


Pierre 



>________________________________
> De : James Ewen <ve6srv at gmail.com>
>À : talk-ca <talk-ca at openstreetmap.org> 
>Envoyé le : Vendredi 9 novembre 2012 17h31
>Objet : Re: [Talk-ca] Edmonton / Strathcona boundary limits
> 
>Oops, the original message below was supposed to go to the talk-ca
>group but I forgot to re-address the message.
>
>I'm not sure that I understand why we would expect to see 100% of the
>Canadian land mass covered by shapes at admin level 6 or any other
>admin level. Not all of the country is organized and governed at that
>level.
>
>Once the areas that do fall under admin level 6 are defined and
>displayed, you'll end up with holes where the cities are, but if you
>add cities to the map, the holes get filled.
>
>Now if you were talking about admin levels 8 (city/town/village/hamlet
>boundaries) and 10 (neighborhoods), I would suggest that these would
>overlap, since the neighborhoods are a subset of the city. Cities in
>Alberta are not a subset of a municipal district.
>
>BTW, Pierre thank you very much for your help and guidance thus far.
>I'm making headway on adding features that I have long wanted to
>ensure were part of the map.
>
>James
>VE6SRV
>
>On Fri, Nov 9, 2012 at 11:02 AM, Pierre Béland <infosbelas-gps at yahoo.fr> wrote:
>> James,
>>
>> For such matters, it is important that contributors assure coordination and
>> use the same rules. This is more a OSM technical problem were OSM has to
>> take into account the administrative structure of each province or country.
>>
>> My understanding is that when you build such a hierarchy of boundaries, you
>> should cover all the territory at each level. If there were no level 6 for
>> Edmonton, there would be a hole at level 6.
>>
>> When we look at a map of  boundaries at level 6, we expect all the territory
>> to be covered.
>> See
>> http://layers.openstreetmap.fr/?zoom=5&lat=52.59638&lon=-118.12528&layers=B00FFFFFFFFFFTFFFFFFFF
>>
>> If  Edmonton was not defined at this level, this would create problems.
>>
>> There were discussions before that we both are note aware off. Some people
>> may also know how contributors have addressed this problem in other
>> countries. This is why I suggest that this be discussed ont the talk-ca
>> list.
>>
>> Pierre
>>
>> ________________________________
>> De : James Ewen <ve6srv at gmail.com>
>> À : Pierre Béland <infosbelas-gps at yahoo.fr>
>> Envoyé le : Vendredi 9 novembre 2012 12h20
>> Objet : Edmonton / Strathcona boundary limits
>>
>> On Fri, Nov 9, 2012 at 10:06 AM, Pierre Béland <infosbelas-gps at yahoo.fr>
>> wrote:
>>
>>> I have duplicated the relation.
>>> Now, there are two relations
>>> level=6 http://www.openstreetmap.org/browse/relation/2564500
>>> level=8 http://www.openstreetmap.org/browse/relation/2563550
>>>
>>> My understanding is that there should be a relation for each level. We
>>> should not leave any hole at level 6 and cover all the province territory.
>>> Making a search throug Nominatim, it still works fine.
>>>
>>> From this point, you should discuss this on the talk-ca list before trying
>>> to make any modification.
>>
>> Okay, what's the story with this concept?
>>
>> The City of Edmonton is an entity unto itself. It falls under
>> admin_level 8 as per the wiki
>> (http://wiki.openstreetmap.org/wiki/Admin_level) as a city. It is not
>> part of any other administrative jurisiction (i.e. part of a county or
>> other entity) Admin_level 6 defines the boundaries of counties,
>> regional municipalities, improvement districts, etc.
>>
>> Would not having 2 relations, one that defines the city (admin_level
>> 8) and another that defines a non-existent entity (admin_level 6) be
>> considered tagging for the renderer (just to fill a perceived hole)?
>>
>> --
>> James
>> VE6SRV
>>
>
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