[Tagging] Gorges, Canyons, Ravines: natural=valley or new tag?

[Michael Patrick]

> Also, Wikipedia basically says ravine, gorge and canyon are synonyms,
> though as an American from the West, I tend to think of canyons as having
> vertical, rock cliffs, vs ravines and gorges as less steep, but this may
be
> a dialectal difference. ...  Thoughts on this?

1. Wikipedia ( and encyclopedias ) and dictionaries are not authoritative,
in the sense that they provide very superficial general descriptions. Check
the 'references section, and sometimes, with luck, the Wikipedia talk tab
on the page will have references.In this case not.

2. The Proper Name ( map label ) of a feature usually does not correspond
with a formal definition. I.e., the 'Turtle Mountains' in North Dakota (
https://www.dmr.nd.gov/ndgs/NDNotes/images/nn15f6.jpg ) hardly count as
hills elsewhere.

3. There is a science, probably close to 2 thousand years old (
https://en.wikipedia.org/wiki/Geology#History ) that has been naming
natural things and a sub-field called 'Geomorphology' ( approx. a 150 years
old ) which classifies and characterizes similarities and differences,
applying a specific common nomenclature. This is useful when writing papers
and journals so other people globaly know exactly what they are talking
about, and in a practical sense so that Nepalese climbing tourists don't
pack their carabiners when on expeditions to the Turtle Mountains in ND.

4. These folks have their own 'Encyclopedia of Geomorphology', which gives
detailed explanations of what sorts of observable features define a term,
and where terms overlap. ( See page 486 'Ravines and Gullies at
http://bit.ly/2YJca7I ). Various agencies in various countries dealing with
geomorphology nomenclature also publish there own glossaries ( see Part
629–Glossary of Landform and Geologic Terms at
https://directives.sc.egov.usda.gov/OpenNonWebContent.aspx?content=41992.wba
), derived from an American Geologic Institute (AGI) publication.

5. For international features, the National Geospatial Agency GeoNames
Search page ( http://geonames.nga.mil/namesgaz/ ) enables you to look up
the classifications, and what they are called in the local language(s).Open
up the Feature Designations section, and scan through the 'Hypsographic'
listing, and you'll see CNYN/Canyon, searching on Mexico, it gives 1732
cañada. You also get direct links to mapping services so you can look at
the features.

6. Google Image search can be helpful if you are more visually oriented:
http://bit.ly/2H64zVL

> ravine, gorge and canyon are synonyms
They are not, sometimes, in certain parts of the world ravines and gorges
are, but you can find gorges inside of  canyons.

Michael Patrick
Data Ferret
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/tagging/attachments/20190814/ae52b332/attachment.html>