Re: [Tagging] natural=bay on areas

[Martin Koppenhoefer]

sent from a phone

> On 30 Mar 2017, at 22:22, Juan Pablo Tolosa Sanzana  
> wrote:
> 
> Vice versa, the practice is mapping the baseline along the coastline.

in Italy there's a law with actual coordinates for the baseline, but AFAIK we 
are generally using EU data in Europe for the maritime borders (without caring 
about the baseline, there's no tag for it)

cheers,
Martin 
___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] natural=bay on areas

[Juan Pablo Tolosa Sanzana]

I didn't know about the practice of mapping the coastline along the baseline, 
AFAIK we don't map the baseline, only their 12nm offset (maritime borders)



Vice versa, the practice is mapping the baseline along the coastline. 
But I think this is no a good idea, because baseline extend up a bit 
outside of the coastline, if the baseline runs along the low tide. In 
some places the tidal range is huge.


The example of  Rio de la Plata exposed previously is clearly poorly 
mapped according the definition of natural=coastline. Note that 
according IHO Rio de la Plata is a sea.


___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] natural=bay on areas

[Andrew Harvey]

On 30 March 2017 at 07:41, Juan Pablo Tolosa Sanzana
 wrote:
> An exact limit between the open ocean and a sheltered coast is too arbitrary
> as natural feature. It seems a political issue. You can use
> boundary=maritime + border_type=baseline for excluding internal waters from
> the open ocean, according of laws of the country. Check the article
> https://en.wikipedia.org/wiki/Internal_waters

I'm looking to tag natural features as surveyed on the ground, not
political or administrative boundaries. Sure the boundary is fuzzy but
we can still get it close.

On 30 March 2017 at 08:00, Christoph Hormann  wrote:
> No, it is not a political issue, the position of the baseline is not in
> doubt here.  If Andrew wants to indicate the sheltered nature of the
> coast in some way via supplemental tags that seems perfectly fine - as
> long as these tags are documented and verifiable of course.
>
> In any case tagging the bay as natural=bay will already indicate this
> part of the coastline to be of special nature.

Agreed. coastline=pelagic, natural=ria all are potential ways to help here.

For me Botany Bay (http://www.openstreetmap.org/relation/1214649)
isn't part of the open ocean but Bondi Bay
(http://www.openstreetmap.org/node/926183187) is, even though both
offer shelter.

On 30 March 2017 at 18:25, Martin Koppenhoefer  wrote:
>> On 30 Mar 2017, at 01:06, Eugene Alvin Villar  wrote:
>> because UNCLOS allows countries to specify a baseline separate from the 
>> coastline that encloses parts of the sea/ocean (thereby making those parts 
>> internal waters of the country) .
> I thought the baseline was generally separate from the actual coastline. It 
> is an administrative construct, while this thread is about natural features. 
> Internal waters, territorial waters , exclusive sea zones, they're all about 
> political and economical power and benefit, not about natural 
> geologic/geographical configurations.

Exactly. According to https://en.wikipedia.org/wiki/Baseline_(sea),
the baseline political, they are like an administrative boundary.
That's a separate discussion, I'm only talking about natural features
here.

___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] natural=bay on areas

[Martin Koppenhoefer]

sent from a phone

> On 30 Mar 2017, at 01:06, Eugene Alvin Villar  wrote:
> 
> because UNCLOS allows countries to specify a baseline separate from the 
> coastline that encloses parts of the sea/ocean (thereby making those parts 
> internal waters of the country) .


I thought the baseline was generally separate from the actual coastline. It is 
an administrative construct, while this thread is about natural features. 
Internal waters, territorial waters , exclusive sea zones, they're all about 
political and economical power and benefit, not about natural 
geologic/geographical configurations.



> 
> If we follow the practice of mapping the coastline along the claimed baseline 
> like in the Rio de la Plata elsewhere in the world, then the Gulf of Sidra in 
> Libya[1] would be considered as an inland waterbody


I didn't know about the practice of mapping the coastline along the baseline, 
AFAIK we don't map the baseline, only their 12nm offset (maritime borders)

cheers,
Martin 



___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] natural=bay on areas

[Juan Pablo Tolosa Sanzana]

By default baselines match with mean low water spring, meanwhile 
natural=coastline is tagged at mean high water spring.


It would be good define some rules related to maritime boundaries don't 
agree with UNCLOS, .e.g. peruvian boundary extends up 200 miles away the 
coastline.


___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] natural=bay on areas

[Juan Pablo Tolosa Sanzana]

I don't know the Australian baseline, this is only an example. Sometimes 
the countries define a straight baseline that close a bay. Of course, 
Andrew have the freedoom to use, e.g. the tag description=* to do the 
mentioned difference.


> No, it is not a political issue, the position of the baseline is not 
in doubt here. If Andrew wants to indicate the sheltered nature of the 
coast in some way via supplemental tags that seems perfectly fine - as 
long as these tags are documented and verifiable of course.
> In any case tagging the bay as natural=bay will already indicate this 
part of the coastline to be of special nature.



___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] natural=bay on areas

[Eugene Alvin Villar]

On Thu, Mar 30, 2017 at 4:41 AM, Juan Pablo Tolosa Sanzana <
jptolosanz...@gmail.com> wrote:

> An exact limit between the open ocean and a sheltered coast is too
> arbitrary as natural feature. It seems a political issue. You can use
> boundary=maritime + border_type=baseline for excluding internal waters from
> the open ocean, according of laws of the country. Check the article
> https://en.wikipedia.org/wiki/Internal_waters
>

Speaking of maritime boundaries and bays and estuaries, the Rio de la Plata
estuary between Argentina and Uruguay is currently modeled in OSM as
*inside* the coastline. If you look at the OSM default carto layer at zoom
5 and lower, where inland waterbodies are not rendered, Montevideo and
Buenos Aires appear to be landlocked inland cities, which doesn't look
right.[1] (See the attached image.) The coastline there follows the UNCLOS
claimed baseline which isn't right because UNCLOS allows countries to
specify a baseline separate from the coastline that encloses parts of the
sea/ocean (thereby making those parts internal waters of the country) when
it meets certain geometric conditions. I think the coastline between
Argentina and Uruguay should include most of the Rio.

If we follow the practice of mapping the coastline along the claimed
baseline like in the Rio de la Plata elsewhere in the world, then the Gulf
of Sidra in Libya[1] would be considered as an inland waterbody, which does
not make sense. Note that the United States have protested as excessive
both the claimed baseline of Libya in the Gulf of Sidra (this resulted in
the Gulf of Sidra incident in 1981) and the joint claimed baseline of
Argentina and Uruguay in the Rio de la Plata.

[1] http://www.openstreetmap.org/#map=5/-35.335/-56.382
[2] http://www.openstreetmap.org/#map=5/31.961/17.249
___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] natural=bay on areas

[Christoph Hormann]

On Wednesday 29 March 2017, Juan Pablo Tolosa Sanzana wrote:
> An exact limit between the open ocean and a sheltered coast is too
> arbitrary as natural feature. It seems a political issue. [...]

No, it is not a political issue, the position of the baseline is not in 
doubt here.  If Andrew wants to indicate the sheltered nature of the 
coast in some way via supplemental tags that seems perfectly fine - as 
long as these tags are documented and verifiable of course.

In any case tagging the bay as natural=bay will already indicate this 
part of the coastline to be of special nature.

-- 
Christoph Hormann
http://www.imagico.de/

___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] natural=bay on areas

[Juan Pablo Tolosa Sanzana]

An exact limit between the open ocean and a sheltered coast is too 
arbitrary as natural feature. It seems a political issue. You can use 
boundary=maritime + border_type=baseline for excluding internal waters 
from the open ocean, according of laws of the country. Check the article 
https://en.wikipedia.org/wiki/Internal_waters


___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] natural=bay on areas

[Martin Koppenhoefer]

sent from a phone

> On 29 Mar 2017, at 14:00, Andrew Harvey  wrote:
> 
> I'd also like to consider how to tag rias, so we can differentiate
> between a ria and the open ocean.


the tag is natural=ria


cheers,
Martin 




___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] natural=bay on areas

[Andrew Harvey]

I've learned a lot from the comments here, based on others comments I
think the solution to my issue is to use a tag like like
coastline=pelagic (from wikipedia "A pelagic coast refers to a coast
which fronts the open ocean, as opposed to a more sheltered coast in a
gulf or bay.") on the oceanic coastline because I'd like separation of
these shorelines within these bays and the coastline facing the open
ocean.

I'd also like to consider how to tag rias, so we can differentiate
between a ria and the open ocean.

___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] natural=bay on areas

[Juan Pablo Tolosa Sanzana]

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  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
 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 

Re: [Tagging] natural=bay on areas

[Christoph Hormann]

On Tuesday 28 March 2017, Andrew Harvey wrote:
> >
> > 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?

My initial assessment was based on an intuitive look on the water 
balance of the bay - which can be backed up with numbers from here:

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.575.3453=rep1=pdf

If you do the math you see that the freshwater inflow is insignificant 
compared to the tidal water exchange.

-- 
Christoph Hormann
http://www.imagico.de/

___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] natural=bay on areas

[Andrew Harvey]

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  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
 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 + 

Re: [Tagging] natural=bay on areas

[Juan Pablo Tolosa Sanzana]

El 27/03/17 a las 16:48, Juan Pablo Tolosa Sanzana escribió:

>>/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 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


> If you're in Botany Bay or the other bays there such as
> https://www.openstreetmap.org/relation/1333569, 
  you're not at sea or

> in the sea, or in the ocean.

Botany Bay is part of the ocean, not a separate inland waterbody. You can see 
in the terrain the mark of the tides.
  
> 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.

> 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.
Here there are instructions to tag an 
estuary:https://wiki.openstreetmap.org/wiki/Proposed_Features/Coastline-River_transit_placement


Sorry, in the last paragraph is boundary=maritime + border_type=baseline 
for outer edge of internal waters.
___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] natural=bay on areas

[Juan Pablo Tolosa Sanzana]

/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 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



If you're in Botany Bay or the other bays there such as
> https://www.openstreetmap.org/relation/1333569, 
  you're not at sea or

in the sea, or in the ocean.


Botany Bay is part of the ocean, not a separate inland waterbody. You can see 
in the terrain the mark of the tides.
 

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.


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.
Here there are instructions to tag an estuary: 
https://wiki.openstreetmap.org/wiki/Proposed_Features/Coastline-River_transit_placement

___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] natural=bay on areas

[Kevin Kenny]

I don't think it does to be too fussy about what is 'river' and what is
'sea' and what is 'estuary'.

Near where I live, a hydrologist would classify the Hudson River as
'estuary' as far as http://www.openstreetmap.org/way/90929525 because it
has a measurable tide right up to that point. Nevertheless, it's fresh
water (the salt front is at least 100 km downstream even in a dry summer),
The actual meeting of river (which, by then, is indeed salt) and ocean is
another 100 km downstream from there.

The locals would be astonished if you were to claim that the bank of the
Hudson River is 'seacoast', even if it has a tide and ships of considerable
size can navigate the river as far as the Port of Albany. A hydrologist
would say, "well, technically, that's correct" and the locals would roll
their eyes.

On Mon, Mar 27, 2017 at 10:05 AM, Kevin Kenny 
wrote:

> I don't think it does to be too fussy about what is 'river' and what is
> 'sea' and what is 'estuary'.
>
> Near where I live, a hydrologist would classify the Hudson River as
> 'estuary' as far as http://www.openstreetmap.org/way/90929525 because it
> has a measurable tide right up to that point. Nevertheless, it's fresh
> water (the salt front is at least 100 km downstream even in a dry summer),
> The actual meeting of river (which, by then, is indeed salt) and ocean is
> another 100 km downstream from there.
>
> The locals would be astonished if you were to claim that the bank of the
> Hudson River is 'seacoast', even if it has a tide and ships of considerable
> size can navigate the river as far as the Port of Albany. A hydrologist
> would say, "well, technically, that's correct" and the locals would roll
> their eyes.
>
>
>
> On Mon, Mar 27, 2017 at 9:28 AM, Christoph Hormann  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.
>>
>> > 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.
>> 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.
>>
>> 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).
>>
>> --
>> Christoph Hormann
>> http://www.imagico.de/
>>
>> ___
>> Tagging mailing list
>> Tagging@openstreetmap.org
>> https://lists.openstreetmap.org/listinfo/tagging
>>
>
>
___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] natural=bay on areas

[Christoph Hormann]

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.

> 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.  
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.

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).

-- 
Christoph Hormann
http://www.imagico.de/

___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] natural=bay on areas

[Andrew Harvey]

> It is a bay of the Tasman Sea/Pacific Ocean.  Ecologically it is a fully
maritime waterbody.

What do you mean by "maritime waterbody"?

If you're in Botany Bay or the other bays there such as
https://www.openstreetmap.org/relation/1333569, you're not at sea or
in the sea, or in 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.

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

On 27 March 2017 at 22:46, Christoph Hormann  wrote:
> On Monday 27 March 2017, Andrew Harvey wrote:
>>
>> What water body is Botany Bay
>> https://en.wikipedia.org/wiki/Botany_Bay part of?
>>
>> I don't think it's right too tag the inside of the bay as coastline.
>> "A coastline or a seashore is the area where land meets the sea or
>> ocean" the inside of the bay isn't the sea, hence the water/land
>> boundary isn't the coastline.
>
> I have had this discussion countless times in other cases and Botany Bay
> is not even a borderline case.
>
> It is a bay of the Tasman Sea/Pacific Ocean.  Ecologically it is a fully
> maritime waterbody.
>
> The only alternative would be to consider it the lowest part of the
> Georges River which would be an extreme stretch considering the size of
> the bay and its connection to the sea compared to the discharge of the
> river.
>
> More elaborate discussion of the matter can be found on the wiki:
>
> http://wiki.openstreetmap.org/wiki/Proposed_Features/Coastline-River_transit_placement
>
> As said a bay is not a separate waterbody in OSM so if you consider
> something a bay you need to decide what it is a bay of.  Tagging
> natural=water + water=bay is always factually wrong (and is also only
> used about 80 times globally).
>
> --
> Christoph Hormann
> http://www.imagico.de/
>
> ___
> Tagging mailing list
> Tagging@openstreetmap.org
> https://lists.openstreetmap.org/listinfo/tagging

___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] natural=bay on areas

[Andrew Harvey]

On 27 March 2017 at 21:35, Martin Koppenhoefer  wrote:
> as there's the coastline as well, it shouldn't produce any problem to remove
> natural=water from the bay. We generally don't add natural=water to the sea:
> https://www.openstreetmap.org/way/148455492#map=13/-33.9809/151.2086
> because they're dealt with by the coastline rendering.

The problem is this bay, is not part of the sea or the ocean.

See https://snag.gy/h51wM0.jpg. The blue area is Botany Bay, the red
is the coastline, and the yellow is the sea and ocean.

The coastline shouldn't go on the inside of the bay, as it's not the
coast. Shoreline yes, but the coastline is only on the coast in red.

Outside Botany Bay you have the Tasman Sea.

On 27 March 2017 at 21:51, Christoph Hormann  wrote:
> Bays are by definition parts of waterbodies and not independent
> waterbodies so they should not be tagged natural=water.  The waterbody
> they are part of should of course be tagged either natural=water or be
> outside the coastline if it is a maritime bay (as in this case as
> tagged by https://www.openstreetmap.org/changeset/46829336).

What water body is Botany Bay https://en.wikipedia.org/wiki/Botany_Bay part of?

I don't think it's right too tag the inside of the bay as coastline.
"A coastline or a seashore is the area where land meets the sea or
ocean" the inside of the bay isn't the sea, hence the water/land
boundary isn't the coastline.

___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] natural=bay on areas

[Christoph Hormann]

On Monday 27 March 2017, Andrew Harvey wrote:
> The wiki for natural=bay says "Since bays are generally part of a
> larger waterbody, either a lake or the ocean, they should not be
> rendered in solid color indicating water themselves."
>
> This creates a conflict with a recent change to Botany Bay
> https://www.openstreetmap.org/relation/1214649 in
> https://www.openstreetmap.org/changeset/47138016.
>
> It was changed from natural=water, water=bay to natural=bay. However
> it most definitely should be rendered as water, contrary to the
> advice on the wiki.

Bays are by definition parts of waterbodies and not independent 
waterbodies so they should not be tagged natural=water.  The waterbody 
they are part of should of course be tagged either natural=water or be 
outside the coastline if it is a maritime bay (as in this case as 
tagged by https://www.openstreetmap.org/changeset/46829336).

-- 
Christoph Hormann
http://www.imagico.de/

___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] natural=bay on areas

[Martin Koppenhoefer]

2017-03-27 12:29 GMT+02:00 Andrew Harvey :

>
> What should we do to fix this? Change the wiki to note that it should
> be rendered as water and fix renders?




as there's the coastline as well, it shouldn't produce any problem to
remove natural=water from the bay. We generally don't add natural=water to
the sea:
https://www.openstreetmap.org/way/148455492#map=13/-33.9809/151.2086
because they're dealt with by the coastline rendering.

Cheers,
Martin
___
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging