On 29 November 2016 at 22:03, Warin <[email protected]> wrote: > Not all embankment have 2 slopes >
To my understanding of the English term, an "embankment" is the equivalent of dyke or levee and is a long, narrow man-made elevation. Therefore they always have two slopes of opposite directions (leaving out the ends) What Martin proposes should get a different tag name to distinguish it from an embankment. The term "on-sided enmbankment" is used in OSM for this, but I do not like it at all. I strongly recommend to use a different tag name. I used "slope" as this is the term used to describe the inclined flanks of levees (=embankments). Length - simple set as the length of the way. Cliffs are tagged as a single way at the top of the cliff, with the right hand side being 'downwards' when facing the direction of the way. Vertical rise - could be tagged with the height key.. this can vary over the length of the feature (I have found this on some maps as a number in meters ... assumed to be the maximum vertical locally rise in meters) To accomodate teh change in vertical height .. put the height on individual nodes? Slope - or in OSM terms 'incline'. This in OSM is entered as a way along the top where the slope would be minimal and not what 'we' want to describe. ... as cliffs, cuttings and embankments are best described this way I think incline may not be the best thing to tag? Humm stairs are described using the incline key ... but on a way that goes up .. leaving the top and bottom free of this. So maybe a top and bottom way .. with a simple way from bottom to top containing the incline information? While the 'top' and 'bottom' of natural features can be a bit fuzzy they are features that should be mapped. Definition? Something for a geologist? Along the lines of the line formed by the intersection of the average slope of land before the change to the average slope of land after the change ( the change being the cliff, embankment or cutting)? On 30-Nov-16 01:25 AM, Volker Schmidt wrote: > If you want to micromap slopes you should create a new key "slope" or > something similar. An embankment has two slopes. It is equivalent to dyke > or levee. The one-side embankments that are defined in the OSM wiki, are in > reality slopes and should be retagged accordingly. > > Independently of the name used fo the tag I see the prblem of defining > where the slope starts, normally these are rounded features. > > On 29 November 2016 at 13:48, Martin Koppenhoefer <[email protected]> > wrote: > >> Currently we are mapping only one side of the embankment (I think it's >> the upper side, but am not sure if the wiki says this explicitly), with the >> direction. What we would IMHO need is a way to map the lower side as well >> and to combine both. A closed polygon will not work I believe. >> >> The obvious solution that comes to mind is a new relation type: in case >> the upper end is mapped, draw a new way for the lower end and combine both >> with a relation (possibly assigning roles like upper and lower, maybe also >> draw lateral ways (ways that connect the ends of the upper and lower ways >> and defines their shape) in cases they are not straight). (The type=area >> relation does this) >> >> Maybe it could also be done without the relation, simply by tagging the >> upper and lower ways accordingly, and connect them at least at one of their >> ends with an explicit lateral way (and respective tags). This would require >> from the data user to topologically search for the embankment area in order >> to be able to render it (or make other use). >> >> What do you think, which representation is better? Are there alternatives? >> >> Cheers, >> Martin >> >> _______________________________________________ >> Tagging mailing list >> [email protected] >> https://lists.openstreetmap.org/listinfo/tagging >> >> > > > _______________________________________________ > Tagging mailing > [email protected]https://lists.openstreetmap.org/listinfo/tagging > > > > _______________________________________________ > Tagging mailing list > [email protected] > https://lists.openstreetmap.org/listinfo/tagging > >
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