OpenStreetMap
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!
Discussion
Comment from n76 on 25 June 2023 at 15:58
Impressive research and list. I hope it can be moved from your user specific area and made a general wiki page.
Comment from Kai Johnson on 25 June 2023 at 20:27
Thanks! Yes, I was hoping to make this a general wiki page after the initial work was done and when there is some consensus that the information is reasonably useful.
Comment from rtnf on 5 July 2023 at 04:46
Oh, last month, I discovered an alluvial fan near my relative’s hometown, but I don’t know how to tag it on OSM.
Instead of using natural=sediment, how about a more direct tagging like natural=alluvial_fan? An alluvial fan is a specific and distinguishable type of sediment, whereas there are several other geographic features that can be categorized as sedimentation.
Comment from Kai Johnson on 5 July 2023 at 13:48
@rtnf, we’re in uncharted territory since none of the tags for alluvial fans are in use yet.
My general inclination is to tag the basic form of the feature using
natural=*and usegeological=*to be more specific. So I might keepnatural=sedimentand addgeological=alluvial_fan.One thing about using the
natural=*tag is that it might bump into other things that could be tagged at the location, e.g.natural=wood. That’s a little less likely with thegeological=*tag.All of this is definitely open for discussion and I would encourage some experimentation. Let’s try some things to figure out what works best and what the community likes best!
Comment from stevea on 9 July 2023 at 20:07
Kai: This is impressive research and the fruits of your excellent results here might next turn into a wiki page that “eases into” an early version of a Proposal.
That way, others can edit in the wiki itself (or using its Talk page for Discussion) and you’ll have robust dialog beyond these Diary entries of yours — which are a great first step! I see you are going to turn this into a “general wiki page,” which is a great next step, though I’d encourage you to be thinking along the lines of Proposal sooner rather than later. (But not until it’s actually “ready,” of course).
In the software development (and quality assurance / testing, and release to the public…) world — my professional background — what you have here is a solid “mid-development” (maybe late-development) version, as it has some question marks, blank spots and so on. That’s not a criticism, just an observation. When you think it is at what might be called an “early alpha,” where the “essential features are complete,” I’d move this to what you specify as at least that wiki you mention, if not an early Proposal (in the OSM wiki way we do things), noting that wide participation for improvement and “fill in the blanks” (with what OTHERS know, or what is relevant for landforms in parts of the world of OTHERS…) is quite welcome. You’ll likely get an even wider dataset (though, this one is pretty amazing already). Plus, with a well-structured proposal that gets Approval, adding additional tags in the wild is fairly straightforward, you can actually simply “do this,” but having the Approval gives these tags firm ground to stand on.
Eventually, you and the community will have taken it to a state of “beta,” where there are no (major) omissions, only relatively minor tweaking is left to do, “the door is closing” for any real substantial changes, and you can “fine tune” it into a ready-to-be-voted-upon Proposal. (Going from beta to “final”). I think this will add real depth and strength to OSM’s data, and worldwide, too.
Based on what I see here, I’d personally likely vote for Approval, but of course, I’d have to see the actual Proposal. Wishing you the best!
Comment from Kai Johnson on 10 July 2023 at 16:48
Thanks for the kind words, stevea!
I don’t think I would want to make an ominbus proposal of everything in the glossary at once, but many of the undocumented tags could be ready for individual proposals to document existing usage, and there are several open proposals that I think deserve support:
I hope that mappers will support these proposals by commenting on them either in support of the proposals or to suggest improvements. And I hope that mappers will find these tags to be appropriate and useful when they’re mapping.
Comment from EvertonBortolini on 10 July 2023 at 18:56
Great job! I believe is important your idea to combine tags such as “natural=…” (or other generic keys and values) and “geological=…” in the same feature in OSM, because an amateur mapper or non-geologist can map these features yet. At the same time, OSM can turn a complete database to geologists, because tags schemes will be compatible with geological map schemes. OpenStreetMap is an important tool for citizen science!