Opened 8 years ago

Last modified 8 years ago

#4510 new defect

canal/river polygon is not a lake

Reported by: ligfietser Owned by: potlatch-dev@…
Priority: major Milestone:
Component: potlatch2 Version:
Keywords: Cc:


Bodies of water (canals, rivers, streams) are often tagged as linear waterways but they should be rendered as natural=water or waterway=riverbank

This mistake is made by mappers who are mislead by the presets in Potlatch 2, because when a polygon is tagged with natural=water, the presets show this as a lake. It is understandable that they want to improve this fault and choose "canal" or "river" element in the menu, not knowing this will be tagged as waterway=canal or waterway=river which should be a linear element only.


For example here a mapper (revision 5) tried to "fix an error"

Can this be changed in the presets? The term "Lake" could be replaced by "water"?

Change History (1)

comment:1 Changed 8 years ago by stevage

Ok, so there are a few things going on here:

  1. Closed loops for waterway=* are always rendering in P2 as filled polygons (which is misleading)
  2. There's no distinction made or guidance offered to help choose between linear features and area features.
  3. The "lake" feature is a little misleading, but IMHO this mostly comes down to the underlying tag names (a lake and a reservoir are in some cases the same thing, yet one is natural=water, the other landuse=reservoir)
  4. The "riverbank" feature would be a very unintuitive choice for most mappers, even though it's the right one. The user is thinking "I'm mapping a river", not "I'm mapping riverbanks".

I don't think just changing "lake" to "water" helps much, but these might:

  1. A visual indication for which features should be applied to linear or area ways
  2. Guidance text explaining how a feature should be used, when it's applied (eg, "Use the Canal feature for a single way running down the middle of a canal.")
  3. Showing the tags that actually get applied, even in Basic mode. (I think there are separate requests for this)
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