[Tagging] Definition of lake/pond as applied to stream/plunge pools

[Kevin Kenny]

On Mon, Dec 21, 2020 at 1:41 PM Paul Allen <pla16021 at gmail.com> wrote:

> On Mon, 21 Dec 2020 at 18:13, Brian M. Sperlongano <zelonewolf at gmail.com>
> wrote:
>
>>
>> "Occasionally a river or stream will form a stream pool or plunge pool,
>> which are bodies of water that naturally occur along the course of the
>> waterway. These waterbodies may either be tagged as a lake or (usually)
>> pond if they are named or significant in size, or else they can be simply
>> conflated with the river."
>>
>
> I think you need to expand a little on how to "conflate" a pool with a
> river.  The
> disadvantage of doing so is that the pool then cannot have a name assigned.
>
> Also, there are tidal pools (which may be outside the scope of the
> proposal).
>
> Is this distinction satisfactory?  How are folks tagging these features?
>>
>
> I've been tagging them as ponds, for lack of anything better.  Well,
> until a few days ago I didn't realize the distinction between ponds
> and pools so I was tagging them as ponds because I didn't know
> they weren't ponds but pools.  If I'd had to map bigger ones
> I'd have tagged them as lakes.
>
>
I've been tagging them as `natural=water`.  :)
Or maybe `waterway=riverbank.`.


In the karst terrain around here, you sometimes have to do more geologic
investigation than I have time for to determine what's actually retaining
the water in a waterbody, and there are plenty for which the distinctions
are unclear anyway. https://www.openstreetmap.org/way/226924460 appears in
origin to be a glacial tarn.  It has an outflow stream, but the majority of
the water exits through percolation (there's no identified sinkhole) into
the caves beneath, and tracers injected into the water have appeared in
several of the stream outlets below the cliffs
https://www.openstreetmap.org/way/595609787.   In a dry summer, the outflow
stream may stop flowing entirely, but the lake never dries up.  So is that
a tarn, or a doline, or (considering that humans have actually dammed the
outflow stream in an effort to preserve the boating value of the lake) a
reservoir?  Frankly, I don't care very much. I have no ambition to produce
a detailed map of the local surface geology, which is horrendously
complicated. It's a permanent body of fresh water, navigable by pleasure
boats. If someone else wants to try to fill in the geologic details, be my
guest!

I might tag as `waterway=riverbank` (the commonest usage around here) if
there's no good reason not to keep the plunge pool separate from the river,
as at the base of https://www.openstreetmap.org/node/5844315874.



-- 
73 de ke9tv/2, Kevin
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/tagging/attachments/20201221/5f8520da/attachment.htm>