[Tagging] Feature Proposal - RFC - Topographic Prominence

[John Willis]

> On Sep 25, 2018, at 9:51 AM, Joseph Eisenberg <joseph.eisenberg at gmail.com> wrote:
> 
> I don't think it works call each of those local high points on Mt Fuji's crater a "hill", if they are all at >3000m elevation with steep slopes dropping >1000 meters down to the valley or plain below.


I think it does - because the rim  and the drop-off doesn't belong to them really —  it is a property of the the caldera / overall mountain. 

It is only their height above the low point of the caldera rim that truly matters (most of the time). 

the caldera / crater is the “mountain”  - the little peaks are hills around the caldera rim. 

they sit upon it, like an ant on my head. they do not get to inherit my head as part of their height *when* deciding if it is important or not. Otherwise, each hair on my head would count as a =person - which is what we are doing now, which seems counter-productive. 

The highest point may be one of those little peaks, and where everyone goes, and it has the highest =ele value of all the little peaks, ***but the =ele value is shared with the =volcano tag as well***. 

I know there are mountains where the lesser peaks are important — Mt hoei on the side of Mt Fuji is a good example — but for most little points on calderas/stratovolcanoes I am familiar with, they are little ant-size “peaks” that stand upon the body of the volcano. 

They may have a large MSL elevation, but very little importance unless you are on the mountain itself. Very few people could name any of them, whereas Mt Fuji itself is internationally famous. I assume the same is true for most mountains - local, regional, or national). 

This confusion lead to some horrible mis-tagging of mount fuji I just repaired. 

there was a =volcano tag for Mount Fuji, A =volcano tag for the crater of mount fuji, a =peak tag for one of the small peaks *with* a (mount fuji) parenthetical, and an incomplete =cliff+ =volcanic_caldera_rim line around the crater. 

=cliff+ =volcanic_caldera_rim line for the rim of the crater/caldera. 

=volcano tag for the body of the volcano, centered in the caldera. 

= peak or =hill for the little points around the edge (whatever solution is agreed upon). 

it would be nice if there was a "caldera relation" to connect them all together, which would allow the rendering of the named, yet overall unimportant =peaks to be reduced. 

This would exclude =peaks on the “arms” of large mountains or further down the sides (like Mt Hoei), which might have to be solved by another tagging solution.]

Javbw
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