On Friday 17 August 2018, SelfishSeahorse wrote: > > > > Yes, that was the obvious attempt to expand the narrow scheme to > > other parts of the world in a superficial way oriented at the > > standard style rendering but not at the actual semantics. > > Actually, it's only drain that doesn't seem to make sense > semantically, but ditch seems to be fine for smaller canals used for > drainage and irrigation, at least according to the definitions by > Wikipedia[^1] and the Cambridge Dictionary[^2].
The meaning of tags in OSM however does not necessarily have anything to do with the meaning of the English language words used for key and value. waterway=drain and waterway=ditch were both from the beginning intended and used primarily for structures transporting away undesirable water. > I'm not sure if a (smaller) mill race can also be called a ditch, but > i think it makes sense to have at least two tags for man-made > channels of different width. Because that works so great for natural waterways? I would say if you want to document the width then tag width=*. > In my opinion the material of the lining/confine should better be > tagged separately, perhaps confine:material=concrete/wood/.... > > As for natural waterways, I could imagine the following > classification based on width: > > * waterway=stream/brook - possible to jump across (< 1 m wide?) > * waterway=creek - small to medium-sized natural stream (1-3 m wide) > * waterway=river (3-10 m wide) > * waterway=broad_river (> 10 m wide) Somewhat off topic here - but as said you cannot change the meaning of a tag that is used hundreds of thousands of times. > Of course we could just use width=*, but it's not always easily > possible to measure the width (e.g. in a forest) and sometimes it > changes often. I would translate this into "i want a subjective non-verifiable classification system but i hide this by defining pro forma verifiable criteria for the classes". If you want to map the river width tag width=*, if you don't want to map the width then don't create classes based on width thresholds. -- Christoph Hormann http://www.imagico.de/ _______________________________________________ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging