[OSM-talk] Planned rendering changes of protected areas

[Christoph Hormann]

On Thursday 30 November 2017, Daniel Koc4‡ wrote:
>
> I'm thinking about changes in rendering of protected areas on
> osm-carto and I wanted to give community a hint, because it's a
> popular kind of objects.

I have no definitive opinion on the tagging question but i consider your 
approach here highly questionable.  More details on that in the 
following.

> 1. Currently leisure=nature_reserve (old scheme) and boundary=* (new
> scheme) are frequently tagged in parallel, and it looks like the old
> scheme is used as a hack just to make it visible on default map.

Presenting leisure=nature_reserve as an 'old scheme' and 'boundary=*' as 
a 'new scheme' is a serious mischaracterization.  The tags 
leisure=nature_reserve, boundary=protected_area and 
boundary=national_park all started being used around the same time.  
There is no old and new here.

There are 62k uses of boundary=protected_area and 77k of 
leisure=nature_reserve and 31k of the combination - which does not 
really support your idea that the latter is used just as a hack.

> 2. The old scheme is too generic and it causes visual clutter,
> because all of the protected areas are displayed at once.

That is frankly just nonsense.  If rendering (or not rendering) features 
with leisure=nature_reserve, boundary=protected_area or 
boundary=national_park causes visual clutter in a map depends on if and 
how you render these features.  That is the responsibility of you as a 
map designer.  Blaming a tagging scheme for not being able to do that 
without visual clutter is a bit strange.

> 3. New scheme has many classes defined, which would allow us to fine
> tune the rendering (different zoom levels and only some of them).

Have you looked at if these classes are actually used consistently at 
the moment?  A tagging scheme with ~25 numerical codes as classes with 
fairly brief and abstract descriptions is not usually destined for 
success in OSM.

> 4. The new scheme looks like more general than the old one, so it's
> all that's we really need.

Which is just another way of saying boundary=protected_area is much less 
meaningful than leisure=nature_reserve since the latter at least 
specifies it is nature protection while the former does not.

You are also contradicting yourself here - in 2. you say "the old scheme 
is too generic" and here you say "the new scheme looks like more 
general" - which is it?

On a general note: Please do not mix tagging discussions and rendering 
discussions - that is a recipe for desaster.  If rendering 
considerations lead you to realize tagging issues and you want to 
discuss those that is fine but then drop arguing for certain tagging 
ideas based on your perceived needs for rendering.  Tagging decisions 
should be based on how mappers can best document their knowledge about 
the geography.  Not on what some developers find convenient for 
rendering.

-- 
Christoph Hormann
http://www.imagico.de/