[Tagging] Tagging Digest, Vol 108, Issue 162

Dave Swarthout daveswarthout at gmail.com
Sat Sep 29 05:10:05 UTC 2018


@Joseph,

>I suppose section=* with railway=* can be treated differently than
section=* with waterway=section, but it’s not ideaI

On second thought, I agree, it's probably not a big issue.

>These proposals all appear to keep one way for the waterway=river, with
the way split for each long section. So a node is named for a short hazard
or rapid, but longer sections are named on the same way >as the river.
That’s why they choose to use :section_name=* instead of just name=*

That's what I was getting at earlier. The river name must stay the same
even though the various "sections" will often have different names. Also,
if one needed to name a shorter section within a longer section, you could
use a relation. Whether the shorter "inner" sections would ever be rendered
is another question but certainly custom maps could be programmed to take
these sections and their names into account. Another observation that
raises yet another question is why the whitewater proposal uses
section_name rather than section:name as the key. AFAIK, the underscore
character is used to connect two words that are meant to be treated as one,
e.g., man_made, while the colon character ":", is often used to
differentiate different subkeys of a major key, e.g., source:position or
source:name. How do you see this?

I am not a whitewater person but even if I were, I wouldn't volunteer to
take on such a project. I hate writing anything in the Wiki. It's a
difficult and arcane piece of software IMO and I have no desire to wade in
and learn it. Life's too short.

Dave

On Sat, Sep 29, 2018 at 7:07 AM Joseph Eisenberg <joseph.eisenberg at gmail.com>
wrote:

> I suppose section=* with railway=* can be treated differently than
> section=* with waterway=section, but it’s not ideal.
>
> I spent some time looking at the whitewater proposals, which introduced
> tags for whitewater:section_name and whitewater:rapid_name, in addition to
> whitewater grades for rapids and river sections, and POIs for river
> hazards, put-in points and take-out points for rafts/kayaks/canoes:
> https://wiki.openstreetmap.org/wiki/Whitewater_sports
>
> These proposals all appear to keep one way for the waterway=river, with
> the way split for each long section. So a node is named for a short hazard
> or rapid, but longer sections are named on the same way as the river.
> That’s why they choose to use :section_name=* instead of just name=*
>
> There is some value to this approach, because it won’t lead to multiple
> overlapping ways for each river. But it wouldn’t be possible to name a long
> section and a shorter reach or bend which is part of a long river section,
> except by tagging a node only, without creating separate ways.
>
> It used to be possible to see the whitewater tags on a layer at
> openseamap.org but it is no longer offered.
>
> Dave, if you have an interest in whitewater sports, there is a great
> opportunity for someone to revive one of the proposals and get it approved,
> in addition to tags that could describe flat water rivers and canals for
> general boating. But it looks like a big project.
>
>
> On Sat, Sep 29, 2018 at 8:20 AM Dave Swarthout <daveswarthout at gmail.com>
> wrote:
>
>> One other thing about the section key I just learned from Taginfo.
>> Although undocumented it has had some use already to describe sections of a
>> railway. So maybe we need to make it easier to distinguish between those
>> uses? Or maybe not.
>>
>>
>>
>>
>> On Sat, Sep 29, 2018 at 5:53 AM Dave Swarthout <daveswarthout at gmail.com>
>> wrote:
>>
>>> It appears I was too hasty about dismissing the reach argument. Yes,
>>> that makes sense Colin. And Joseph's suggestion to make it more general
>>> sounds good too. I think the name part needs to be set up to distinguish
>>> the name of the bend or reach from that of the river because both are valid
>>> for any section. The hierarchy below would fill the bill and more than
>>> satisfy my sense of orderliness. LOL
>>>
>>> waterway=river
>>> name=Tanana River
>>> waterway=section
>>> section=bend
>>> section:name=Harper Bend
>>>
>>> I like what we've come up with so far. Any more suggestions?
>>>
>>> Dave
>>>
>>> On Sat, Sep 29, 2018 at 5:15 AM Joseph Eisenberg <
>>> joseph.eisenberg at gmail.com> wrote:
>>>
>>>> Do canals have named sections?
>>>>
>>>> Waterway=section would work for canals too, if there are such a thing
>>>> as canal reaches or sections or bends
>>>>
>>>> On Sat, Sep 29, 2018 at 5:32 AM Colin Smale <colin.smale at xs4all.nl>
>>>> wrote:
>>>>
>>>>> On 2018-09-28 07:37, Dave Swarthout wrote:
>>>>>
>>>>> The discussion about the definition of "reach" is interesting but IMO
>>>>> it's slightly off topic.  Perhaps, because of those differences in its
>>>>> interpretation, we would be best served by not using the term at all.
>>>>>
>>>>>
>>>>> The point of raising the "reach" business it to help abstracting the
>>>>> proposed tagging model to make it more generic. If we consolidate all the
>>>>> thoughts expressed so far, we can say that:
>>>>> * there can be contiguous linear sections of a river which can have
>>>>> names
>>>>> * they can be "straight" (for example "reaches") or "curved" (for
>>>>> example "bends")
>>>>> * they can (partially) overlap each other, and there may be gaps
>>>>> (there may not be a clear, sharp transition from one section to the next)
>>>>> * they encompass the entire width of the river and are not just a 2D
>>>>> line
>>>>>
>>>>> This is pointing towards:
>>>>> * a way along the centre line of the river (colinear with the
>>>>> main_stream lines?)
>>>>> * waterway=river_section
>>>>> * river_section={reach,bend,...}
>>>>> * name=*
>>>>>
>>>>> Is this a basis that we can work incrementally forwards from?
>>>>>
>>>>> _______________________________________________
>>>>> Tagging mailing list
>>>>> Tagging at openstreetmap.org
>>>>> https://lists.openstreetmap.org/listinfo/tagging
>>>>>
>>>> _______________________________________________
>>>> Tagging mailing list
>>>> Tagging at openstreetmap.org
>>>> https://lists.openstreetmap.org/listinfo/tagging
>>>>
>>>
>>>
>>> --
>>> Dave Swarthout
>>> Homer, Alaska
>>> Chiang Mai, Thailand
>>> Travel Blog at http://dswarthout.blogspot.com
>>>
>>
>>
>> --
>> Dave Swarthout
>> Homer, Alaska
>> Chiang Mai, Thailand
>> Travel Blog at http://dswarthout.blogspot.com
>> _______________________________________________
>> Tagging mailing list
>> Tagging at openstreetmap.org
>> https://lists.openstreetmap.org/listinfo/tagging
>>
>

-- 
Dave Swarthout
Homer, Alaska
Chiang Mai, Thailand
Travel Blog at http://dswarthout.blogspot.com
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