[Tagging] natural=water inside natural=wetland

[Florian Lohoff]

On Thu, Apr 30, 2020 at 04:36:31PM +0200, Jean-Marc Liotier wrote:
> Consider a wetland that contains a water body. I'm used to map that as
> natural=water inside natural=wetland - no multipolygon fanciness, just one
> on top of the other. JOSM validator complains about it, which irks me, so I
> opened a ticket at https://josm.openstreetmap.de/ticket/19171 - where mdk
> suggests that I may be doing it wrong...
> 
> Is my simple way incorrect ? It feels correct to me because wetlands are
> complex objects - water bodies are part of them, cross them or partially
> overlap them. From a tagging point of view, it implies that some area is
> both natural=water and natural=wetland - I see no problem with that... But
> others might consider that a logical impossibility.
> 
> So, which is the correct way: plain natural=water inside natural=wetland, or
> a natural=water multipolygon with natural=wetland on its inner ?

I have myself some QA stuff running and i also do consider this a bug.
A squaremeter can either be wetland or open water e.g a pond. So
cant simply layer them.

I also do consider overlapping natural and landuses to be a bug,
either its a natural=scrub or a landuse=farmland. It cant be both.

I agree that there are corner cases where this fails. E.g a pond
in a landuse=residential or landuse=forest. Its still the forest.

Flo
-- 
Florian Lohoff                                                 f at zz.de
        UTF-8 Test: The 🐈 ran after a 🐁, but the 🐁 ran away
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