[Tagging] Stop the large feature madness (was: Tag for a plateau or tableland?)

Frederik Ramm frederik at remote.org
Wed Apr 17 09:29:50 UTC 2019

Josh & others,

I think we need to take a break here from making OSM into a map of
large-scale geographic features.

This is getting out of hand. I vividly remember the endless discussions
about bays and peninsulae. Drainage basins. Now plateaus. I don't
remember mountain ranges in the recent past but if they weren't
discussed then they surely are next.

The way OSM usually works is someone stumbles over something in reality,
with a discernible name or property, and adds it to OSM. We are, first
and foremost, surveyors.

The larger a feature becomes, the less suitable OSM is for mapping it.
And in the case of the several large-scale objects I have mentioned,
most contributors don't even have surveying in mind, but just writing
down existing conventions. I haven't checked, but I would be very
surprised if *anyone* actually used the natural=peninsula tag for
something they happen to identify as a peninsula - no, natural=peninsula
is just a method of putting existing geographical names into OSM
(because the fact that something is a peninsula can be auto-detected).
Same with your plateaus and tablelands now - do you really envisage
someone looking at the landscape around them and saying "why, there's a
hard layer of rock here on top of softer layers, and a couple cliffs at
the sides, I guess I'll map this as a plateau"? No, again this is a
situation where you have third-party information about a plateau (and
likely its name) and are looking for ways to get that into OSM.

All these requests are born from a desire to write down existing
large-scale geological/geographical knowledge. But OSM is ill suited for
that; OSM cannot accommodate imprecise features. If you want to map a
mesa well in OSM then it has to be detectable on the ground, and it has
to have a clearly delineated boundary. What you are trying to do here is
adding large-scale features that come in handy when you want to make a
map ata  1:10m or maybe 1:50m scale. Projects like naturalearthdata.com
are ideally suited for that kind of data. OpenStreetMap is not.

I think we all should stop seeking out one large-scale feature type
after the other that is "missing" from OSM and think about how to best
add them. In my view, the fact that these are underrepresented in OSM is
not an opportunity to "improve" OSM but a sign that OSM isn't the right
place for that kind of data.

Instead, let us find a way of recording such imprecise information
outside of OSM's data model, and make it easy to access it e.g. when
rendering maps.


Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00'09" E008°23'33"

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