[Tagging] Feature Proposal - RFC - River Classification
ilya at zverev.info
Wed Aug 30 09:45:05 UTC 2017
> I originally thought i'd stay out of these discussions on importance tags for rivers (because in the end i don't think there is anything to be gained from it) but this is just too good an opportunity, in particular to ask a former Saint-Petersburg resident: So the Neva:
> should be tagged river=small?
Excellent question Christoph. It made me rethink the thresholds for river sizes, and now they include basin areas and a requirement of rivers forming a network with increasing size.
So the Neva River has a very large drainage basin, way over 15000 km², which makes it big. Also, the Volkhov River, 224 km in length, is in its basin, so the category cannot be less than "big".
Emmor, regarding the classification based on what mapper sees, it is hard to do. Because to make rivers into a network, you must consider the whole network. That's a bit like with highways: you cannot choose its type based only on what you see (except for highway=motorway, of course). My proposed classification requires only checking wikipedia or another source for river parameters. So I assume that is already much simpler that tagging highways, and would help map style authors and other data consumers a lot.
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