[Tagging] waterway=wadi problem

[Mateusz Konieczny]

Can you consider making proposal for waterway=wadi on wiki?
Or maybe other tag, as waterway=wadi is frequently used to mark
intermittent streams?

Currently http://wiki.openstreetmap.org/wiki/Tag:waterway%3Dwadi is
not mentioning anything like that.

Note, I am not disputing usefulness of term wadi. I am disputing usefulness
of waterway=wadi tag due to lack on any agreed definition and description on
OSM wiki.

2015-01-15 3:41 GMT+01:00 johnw <johnw at mac.com>:

> I strongly disagree. A wadi is usually only an active river through very
> rare flash flood events, and almost never any other time.  Entire biomes
> are defined by the presence of (and situated in) a wadi.
>
> In america, the words Arroyo and wash roughly translate into wadi, and
> because of the ambiguous nature of arroyo, the term wadi is used for a wash
> or arroyo when referring to a usually dry stream/riverbed that is dangerous
> in flash flood conditions.
>
> my experience with washes stems from the Southern California Desert, where
> most of the state park would basically be covered in blue, if washes were
> somehow labeled as rivers - some are 100m across.  Whole road systems exist
> in the washes (and are reestablished purely by use after a flood), as the
> rest of the land is almost impassable.
>
> I have driven a couple thousand miles in a roughly 50x50 mile box over a
> hundred or so driving trips, and only on 3 occasions was water ever
> present, and at that time, the roads were completely impassable (a meter or
> so of water filled up the Carrizo wash 30m wide).
>
> Although several famous arroyos (like the LA River) are now basically
> man-made drainage ditches, mapping desert areas properly requires the wadi
> tag, as they are different from intermittent rivers - in the fact that
> water in the “bed" is *never expected* - even seasonally - and if present
> it is a dangerous flash flood. There is never an in-between state of what
> you would call “a river” for longer than a day. - as it disappears almost
> immediately as soon as the flood is over (except in the most exceptional of
> weather conditions).  - kind of like an avalanche is only an avalanche
> while it is moving, or an earthquake is is an event.
>
> A wadi is a place where flash floods occur. It is not an intermittent
> river - it isn’t really seasonally wet, and doesn’t provide any real
> expectation that water will be present (except deep underground) - because
> they are located in places where rain itself is unexpected for most of the
> year.
>
> A wadi has an expectation of always being dry, except for the rare and
> unpredictable flash flood. t and in that case, you should assume it is a
> dangerous, and impassable place.
>
> I think, espcially since it is defined and used so heavily, and has a
> different connotation than a river - even a intermittent one, it should be
> kept.
>
> a wash near Borrego springs, CA (ironwood wash, Tubb canyon). it drains to
> a sink in the middle of the desert (the white spot in the upper right)
>
> https://www.flickr.com/photos/javbw/11091366554/in/set-72157638113734675
>
> https://goo.gl/maps/fpSxE
>
> Javbw
>
>
> On Jan 14, 2015, at 11:45 PM, Mateusz Konieczny <matkoniecz at gmail.com>
> wrote:
>
> waterway=wadi is used (18 180 times) and has some support (for example
> JOSM and
> default map style).
>
> During implementing rendering of intermittent=yes I discovered major
> problem with this tag -
> the same waterway=wadi may be used for completely dried up waterway,
> intermittent stream,
> intermittent major river and intermittent ditch.
>
> Therefore - it seems that using waterway=river/canal/stream/ditch/drain +
> intermittent=yes is
> clearly superior to using waterway=wadi.
> _______________________________________________
> 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
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/tagging/attachments/20150115/45aaffd6/attachment.html>