In the course of working with GNIS data from the US Geological Survey, I’ve sometimes been frustrated with the limited range of expression in OSM tags for natural features. For example, we have a lot of tags that can be applied to a Bench as a place for a people to sit, but nothing specific to identify a Bench as a geographic landform other than tagging the edges as natural=cliff or natural=earth_bank.
There have been some good efforts to improve geological tagging, such as the Proposal for additional volcanic features and the Categories of Sea Areas, which give us broader vocabularies for some features. Strangely, the seamark:sea_area:category=* tag set is more expressive for undersea features than the OSM tags we have for features on land!
So, I decided to put together a Glossary of landforms for OSM, based on a similar glossary on Wikipedia. In the process, I’ve found that OSM does have a broad set of tags for geographic features, although many of them have limited or no documentation.
I also think that there is an opportunity to expand the values of the geological=* tag to include more types of geological features. If the main tag for a features is natural=* or something similar, that can identify the general shape of the landform and be the main tag used by renderers. The addition of a geological=* tag can add more specificity to the feature and identify the nature and structure of the landform. For example, the famous Sugarloaf Mountain in Rio de Janeiro is not just a mountain, but a Bornhardt. So, we might consider adding a geological=bornhardt tag to the feature.
If you have an interest in mapping natural features, check it out:
Glossary of landforms
It’s certainly a work in progress and there are some prospective tags on the list that aren’t currently in use, but I hope it might be useful. If anyone has input, I’d be very happy to have some additional contributions to the effort!