[Tagging] Feature Proposal - RFC - Waterways classification

[Mark Wagner]

On Wed, 9 Aug 2017 19:13:57 +0200
Daniel Koć <daniel at xn--ko-wla.pl> wrote:

> Definition:
> 
> Classification of waterways using "stream order" systems
> 
> Proposal page:
> 
> https://wiki.openstreetmap.org/wiki/Proposed_features/Waterways_classification
> 
> This is proposition of tagging "stream order" systems only. There can
> be other systems too, but this one is simple and used in cartography,
> so it's good to have a tagging standard for it.

Posted here because I'm tired of fighting ReCaptcha.  If someone who
has *real* wiki editing privileges could put it on the wiki talk page
signed as "Carnildo", I'd appreciate it.

None of the proposed methods of classifying waterways seems appropriate
for OSM:

* "Classic" can be determined from an incomplete data set, which makes
  it possible to add it to OSM.  But by the same token, an end-user can
  easily compute it from the OSM dataset, which means we shouldn't
  include it.  (We don't include things like the lengths of roads or
  the areas of farms for exactly this reason.)
* "Strahler" and "Shreve" require a complete set of a river's
  tributaries to compute.  The vast majority of OSM's river networks
  are incomplete, so unless a mapper has an ODbL-compatible outside
  source, they can't add correct information. In the cases where the
  network ''is'' complete, the same objection to the "classic" ordering
  applies.

Yes, we need a way of differentiating the Mississippi River from the
Elm River, or distinguishing a stream you can cross without breaking
stride from one where you're going to get your feet wet, but this isn't
it.

-- 
Mark