[Tagging] convert imported natural=rock areas to bare_rock

[Christoph Hormann]

On Sunday 13 July 2014, Friedrich Volkmann wrote:
> >
> > The Corine natural=rock areas on the other hand are not
> > natural=bare_rock, neither factually as you can easily check with a
> > few examples nor by definition [2] where it is simply described as
> > "Scree, cliffs, rocks outcrops, including active erosion, rocks and
> > reef flats situated above the high-water mark".
>
> I wouldn't have started this thread without checking a few examples.
> These areas are predominant in high regions of the Alps, the Pyrenees
> and of Corsica. They look "rocky" on areal images. The definition you
> cited conforms with natural=bare_rock, except for scree, which is
> natural=scree. Some of the areas could also be tagged as
> natural=fell. But at least natural=bare_rock wouldn't be any wronger
> than natural=rock.

Replacing one wrong with another wrong does not make it right. ;-)

But even worse this would dilute the meaning of natural=bare_rock.  The 
natural=rock tag is not used anywhere else on larger polygons so there 
is fairly little harm in having these in the database.  But if you are 
worried about this retag them with some specific tag like corine=3.3.2.

It might appear if you do not look too closely as if some of the areas 
tagged natural=rock in France are indeed mostly bare bedrock but as 
said overall they mostly are a mixture of all kinds of stuff from 
bedrock to mud with mostly one thing in common, that is they are 
largely lacking vegetation.  natural=bare_rock OTOH is predominantly 
exposed bedrock  The fairly typical landscape in both Pyrenees and 
Corsica of rocky terrain with scattered trees, scrubs and grass, like:

http://commons.wikimedia.org/wiki/File:France_Pyr%C3%A9n%C3%A9es_Lac_N%C3%A8re_%28Vall%C3%A9e_de_Bar%C3%A8ges%29.jpg
http://commons.wikimedia.org/wiki/File:Port_du_Marcadau_-_versant_espagnol.jpg
http://commons.wikimedia.org/wiki/File:Etang_de_caraussan_aerien.JPG
http://commons.wikimedia.org/wiki/File:Grand_Cambal%C3%A8s.jpg

does not qualify as natural=bare_rock in total even if locally there is 
exposed bedrock of course.

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