[Tagging] Feature Proposal - RFC - Topographic Prominence

[John Willis]

> On Sep 25, 2018, at 12:14 PM, Kevin Kenny <kevin.b.kenny at gmail.com> wrote:
> 
> I live in country with long ridges, and almost anything with enough isolation and a little bit of prominence winds up being a named summit.

Yea, long strings of peaks are difficult to deal with.

A caldera relation would handle a single volcano with many named peaks, such as Mt Akagi - they look like an alligator floating in a pond. 

https://www.flickr.com/photos/javbw/23360789861/in/album-72157638113676925/

Sometimes, depending on the angle, they appear as a range, but it when viewing from above, their circular nature is present. 

The big blue mountain ridges are circular volcanoes (Mt Haruna) and collaped volcanoes (Mt Miyogi). 

https://www.flickr.com/photos/javbw/6752512409/in/album-72157638113676925/

But making a relation to handle your example is very difficult, similar to the many long, layered mountain ranges made by tectonic action in Japan. 

I don't know how to handle such things. 

https://www.flickr.com/photos/javbw/11091212455/in/album-72157638113676925/

https://www.flickr.com/photos/javbw/6752512409/in/album-72157638113676925/

Also, Japan is very young geologically, and the extreme erosion from the rain has brought several square KM of soil down into the valleys (along with quarantary volcanic eruptions) , making soft hills that stick up everywhere. Every lump has a name, and even little lumps on lumps have names. 

https://www.flickr.com/photos/javbw/11091304694/in/album-72157638113676925/

Each of these situations: 

- calderas and very large peaks with named features 
- ranges and ridges of jumbled random peaks 
- lumpy hills and "mountains" on flat/gently sloping  terrain 

Might require a unique approach. 

=Peak is unsuited to handle all three, and simply using ele or a prominence score probably can't either. Both are important components, though. 

I agree it will only be mapped correctly via the opinion of local/regional mappers - but having them "tune" or "adjust" the values after a programaticaly generated solution might be best - however I have no idea how that might be done. 

Until then, giving mappers the tools to denote "importance" to mountains the same way we do for roads (track to trunk) and waterways (ditch to river) is the only viable way forward. 

Javbw. 

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