[Tagging] Feature Proposal - RFC - Tag:natural=mesa and Tag:natural=butte

[Christoph Hormann]

On Friday 26 April 2019, Joseph Eisenberg wrote:
> I have created 2 proposal pages for natural=mesa and natural=butte
>
> A mesa is defined as "A flat-topped elevated landform surrounded by
> cliffs". A mesa may also be known as a table or tableland, potrero or
> tepui. See http://en.wikipedia.org/wiki/en:mesa
>
> A butte is defined as "a hill with a flat top surrounded by cliffs."
> The width of the flat top is less than the relative height of the
> hill. See http://en.wikipedia.org/wiki/en:butte
>
> [...]

As i understand it a butte is not generally assumed to be flat topped in 
common language use, the key elements here are height larger than width 
and cliffs on all sides.

For mesas i already mentioned the fairly precise criterion that the 
elevation variance along the top (or more precisely the derivation from 
flatness - some amount of tilt in geology is fairly common) needs to be 
significantly smaller than the overall height of the structure.  
Combined with a firm requirement for cliffs on all sides this would 
make a fairly precise definition.

In general for a successful tag explaining precisely and in detail how 
the mapper can distinguish features the tag should be used for from 
ones it should not be used for is key.  Referring vaguely to Wikipedia 
for details is not going to work, the actual meaning of the tag will 
deviate from the Wikipedia description.

It should also be mentioned that these tags are not meant to be a 
substitute for locally mapping the actual cliffs - which while by 
definition surrounding the whole structure can be staggered of course.

For natural=plateau i don't see a chance of this becoming a meaningful 
tag.  Too much inherent vagueness in the very idea.  If you'd try to 
define it more precisely it would almost certainly be advisable to use 
a different tag that is not misleading the mapper to have a much 
broader scope.

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