[Tagging] natural=bay on areas

Wed Mar 29 01:27:34 UTC 2017

No, I just tagged the edge of the bay as natural=coastline because this 
is the top of the tidal range. Even being more rigorous the 
natural=coastline must be shifted far away towards west of current 
position. The lower part of Georges River is a typical ria: an 
unglaciated valley submerged into the seawater.

El 28/03/17 a las 09:47, Andrew Harvey escribió:
> Initially I was concerned that by changing the tagging from
> natural=water, water=bay to natural=bay that the whole bay would be
> rendered as land since that's what the wiki suggests. I now see that
> the same user changed the edges of the bay to be natural=coastline to
> prevent this.
>
> I'm agree now that it makes sense for the wiki to not recommend
> filling bays as water since a bays is either part of the ocean or part
> of some other waterbody like a river, lake, reservoir   etc.). A
> natural=bay as an area can share a common boundary with the riverbank
> like http://www.openstreetmap.org/way/483211748.
>
> I'm not convinced that the inside here should be tagged as
> natural=coastline, as it simply doesn't match the description of what
> a coastline is. I think the solution here is to include botany bay and
> other bays here as part of a waterbody.
>
> On 28 March 2017 at 00:28, Christoph Hormann <osm at imagico.de> wrote:
>> On Monday 27 March 2017, Andrew Harvey wrote:
>>>> It is a bay of the Tasman Sea/Pacific Ocean.  Ecologically it is a
>>>> fully
>>> maritime waterbody.
>>>
>>> What do you mean by "maritime waterbody"?
>> A waterbody where plant and animal life matches or is close to that of
>> the sea rather to that of a river or lake.
> I think it's a grey area, it's not completely like a river, nor that
> of the sea. But in this case, I'm not sure, what information do you
> have that confirms this?
>
>>> Botany Bay is unlike many conventional bays which are on the
>>> coastline and part of the sea. You're right that these types of bays
>>> are part of the sea and ocean, and other times they are part of a
>>> river, but botany bay is really a river nor sea, if anything Botany
>>> Bay sounds much more like an Esturary.
>>> https://en.wikipedia.org/wiki/Estuary
>> In OSM we have no separate tagging for estuaries, this would not make
>> sense because it would just introduce yet another boundary problem
>> (where the river turns into the esturary and where the esturary turns
>> into the ocean).  An esturary is the transit of a river into the ocean.
> That's exactly what botany bay is, a transit of a river into the ocean.
>
>> If you consider the Botany Bay to be part of the esturary of Georges
>> River you still have to decide where you place the coastline and if you
>> place it below the bay you have to tag the bay waterway=riverbank or
>> natural=water + water=river.  Creating a separate waterbody that is not
>> part of the river but within the coastline is wrong in our current
>> tagging scheme.
> I don't have a problem with waterway=riverbank, as many parts of the
> shoreline here are closer to a riverbank than a coastline. That's
> probably the best solution here.
>
>> Note in general the esturary of Georges River would be considered to
>> start much further upstream, likely somewhere around here:
>>
>> https://www.openstreetmap.org/#map=15/-33.9765/151.0237
>>
>> at the transit from a meandering river to a ria
>> (https://en.wikipedia.org/wiki/Ria).
> Thanks for that link!
>
> On 28 March 2017 at 06:48, Juan Pablo Tolosa Sanzana
> <jptolosanzana at gmail.com> wrote:
>> A maritime waterbody are all those waters under the influence of the tides.
>> You can review article for natural=coastline. The coastline should be placed
>> in the "high water mean spring":
>> https://wiki.openstreetmap.org/wiki/Tag:natural%3Dcoastline
> The wiki says "The natural=coastline tag is used to mark the mean high
> water spring line along the coastline at the edge of the sea." The
> last part is key. The tidal limit is way upstream at
> http://www.openstreetmap.org/search?query=-33.9252261917%2C%20150.9283593270#map=15/-33.9252/150.9284
> but since the coastline tag is only marking high water mark on the
> coast (the boundary between sea and land), it shouldn't be used there.
>
>> Botany Bay is part of the ocean, not a separate inland waterbody. You can
>> see in the terrain the mark of the tides.
> So you're saying that anything below the tidal limit is the ocean?
>
>>> If you swim at a coastal beach you're swimming in the sea and the
>>> ocean. At the beaches of Botany Bay, no one would say you're in the
>>> sea or ocean. Nor would they say you're on the coast of Australia.
>> This is only a colloquial thing. That lacks of verifiability. For example,
>> Dead Sea is not a sea, really is a lake.
> What's the verifiable thing on the ground which backs up
> natural=coastline on the inside of the bay(s)?
>
>>> Botany Bay is unlike many conventional bays which are on the coastline
>>> and part of the sea. You're right that these types of bays are part of
>>> the sea and ocean, and other times they are part of a river, but
>>> botany bay is really a river nor sea, if anything Botany Bay sounds
>>> much more like an Esturary. https://en.wikipedia.org/wiki/Estuary
>> The rules for tagging are in the OSM wiki. Even in Wikipedia says Botany Bay
>> is an oceanic bay: https://en.wikipedia.org/wiki/Botany_Bay
>> The coastline is a natural feature. You don't mix it with political things.
>> You can use the tag boundary=maritime + maritime=base_line to delineate
>> political inner waters. Even the boundary runs in the mouth of Botany Bay,
>> therefore is respected local things that you mean.
> Yeah I'm not trying to tag political boundaries, or political maritime
> boundaries. I just strongly feel that
> http://www.openstreetmap.org/way/220111130 is not a coastline.
>
>> Here there are instructions to tag an estuary:
>> https://wiki.openstreetmap.org/wiki/Proposed_Features/Coastline-River_transit_placement
> Thanks for that link, I'll take a read through that and make some
> comments over there.
>
> _______________________________________________
> Tagging mailing list
> Tagging at openstreetmap.org
> https://lists.openstreetmap.org/listinfo/tagging