[Talk-ca] Administrative boundaries Quebec

[Sam Vekemans]

Mapnik -osm2pgsql layers

Thats awesome visualization!

Is it possable to create a mapnik osm2pgsql set of layers that would
allow seeing just select features?

I guess im talking about a wmf service. (which i barely understand)
But wont that require separate hosting of the data?  (or rather, a
rendering of the planet that just has land & sea) where all the other
features can be added with a osm2pgsql layer?

(if you dont follow, thats ok)

All i need to know if its technically possable :) ~ probably just
requires oodles of computing power for it.

Cheers,
Sam


On 1/22/10, Frank Steggink <steggink at steggink.org> wrote:
> Frank Steggink wrote:
>> Frank Steggink wrote:
>>
>>> Hi,
>>>
>>> As a bit of a challenge I've looked at the administrative data pointed
>>> out by Nicolas Gignac: [1]. I know there are some doubts about the
>>> accuracy, but this was also meant as an exercise to deal with this kind
>>> of data. Maybe it can be reused for other purposes, although I haven't
>>> written the tool I used in a generic way. I also hope that the more
>>> accurate (1:20k) data uses the same structure.
>>>
>>> First I converted this data to SHP (with an ESRI tool called Import71,
>>> and then ogr2ogr). Then it was converted to OSM with shp-to-osm.jar.
>>> However, the data has a topological structure, so it has not much value
>>> if it would be imported into OSM directly.
>>>
>>> The set of administrative boundaries contains municipalities, MRCs,
>>> administrative regions (17) and urban agglomerates. The municipal data
>>> contains also information about MRC, admin. regions and agglomerates, so
>>> I decided to examine this further. Now the topological structure was a
>>> benefit, because this is how administrative boundaries should also be
>>> entered in OSM. The boundaries only contain attributes like from-node,
>>> to-node, left-poly and right-poly. However, this is enough to compose
>>> relationships (type=multipolygon/boundary, boundary=administrative,
>>> etc.) out of them. Because I ended with an ArcInfo coverage as a result
>>> of the conversion by Import71, I decided to extract data from the file
>>> pat.adf to get the municipality and other relevant names, codes, etc.
>>>
>>> So far I have only created relationships, including the municipality
>>> name. I would like to share it with you, in order to gather feedback.
>>> The result can be found here: [2]. PLEASE do NOT upload this data to
>>> OSM! The ways are sorted in the relationship, so they form closed
>>> chains. Also the nodes where multiple ways meet have been deduplicated,
>>> otherwise JOSM (and also OSM itself) won't recognize the ways as being
>>> connected. The deduplication was based on the actual coordinates, not
>>> the node IDs used in the topology.
>>>
>>> Things to do:
>>> * Detect which boundary is the outer boundary, and which ones are the
>>> inner boundaries. Obviously, the ring with the biggest surface area is
>>> the outer boundary, and the rest are inner boundaries.
>>> * Add multiple municipalities in the same relationship.
>>> * Create MRCs, administrative regions, and urban agglomerates.
>>>
>>> More information about administrative boundaries can be found in [3].
>>> For Canadian provinces admin_level=4 should be used, for regional
>>> municipalities (MRCs in Quebec) admin_level=6, and actual municipalities
>>> admin_level=8. I would like to propose to use admin_level=5 for the
>>> regions. They have at least a semi-offical status. Others might be able
>>> to elaborate on it more. This leaves the urban agglomerates (Montreal
>>> and Quebec only), for which admin_level=7 would be a natural choice,
>>> although I'm not sure if they have any official status. What do you guys
>>> think?
>>>
>>> Regards,
>>>
>>> Frank
>>>
>>> [1]
>>> http://www.mrnf.gouv.qc.ca/territoire/portrait/portrait-donnees-mille.jsp
>>> [2] http://www.steggink.org/osm/Quebec/quebec_munic.zip
>>> [3] http://wiki.openstreetmap.org/wiki/Tag:boundary%3Dadministrative
>>>
>>>
>>> _______________________________________________
>>> Talk-ca mailing list
>>> Talk-ca at openstreetmap.org
>>> http://lists.openstreetmap.org/listinfo/talk-ca
>>>
>>>
>>>
>> A clarification on this: "Add multiple municipalities in the same
>> relationship." Several municipalities have exclaves, like outlying
>> islands. They are divided over multiple polygons, so I created multiple
>> relations for them.
>>
>> For the higher-level administrative boundaries, I intend to use
>> information from the AAT file which was generated by Import71. This file
>> contains records describing the boundary type. Although there is
>> specific data for each level, in OSM it would be best to reuse the same
>> set of nodes and ways, and that can best be done by using the same
>> source data.
>>
>> Frank
>>
>>
>> _______________________________________________
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>> Talk-ca at openstreetmap.org
>> http://lists.openstreetmap.org/listinfo/talk-ca
>>
>>
>
> Hi all,
>
> The last days I've flexed my Mapnik / osm2pgsql skills, and was able to
> put a visualization of the tiles online. They can be found here: [1].
> The tiles themselves are generated as transparent PNGs, so they didn't
> have to be integrated into the data. Note that I also adjusted the
> zoomlevels, so they are visible earlier than they would be normally.
> Levels 6 - 13 are available, but the last level is still rendering as I
> write this. I haven't take care of any labeling yet, although it is
> present in the DB.
>
> Cheers,
>
> Frank
>
> [1] http://mijndev.openstreetmap.nl/~fsteggink/quebec_admin.html
>
>
> _______________________________________________
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> Talk-ca at openstreetmap.org
> http://lists.openstreetmap.org/listinfo/talk-ca
>


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