Proposal talk:Contour
Wrong method
I don't think these contours should be in the OSM data like the way we store ways. Sure, height maps are very nice to have in OSM, but it'd need it separate data structure as it's data type is completely different. --Eimai 12:20, 1 November 2008 (UTC)
- There are methods of downloading and converting contour data to OSM for the purpose of generating maps, there is absolutely no need to store this data in OSM. Tools like OSM Composer have integrated downloading of such data from various sources, to use this type of data you need a lot of disc space. To implement this in OSM means downloading street data for a simple 2D map is almost impossible. --Skippern 21:04, 4 November 2008 (UTC)
- This is definitely not what OSM is meant for, as this kind of data can have no topological relationship to any other entity in the database; perhaps someone can create an OpenContourMap if they wish to crowd source this data. I'm marking this proposal as abandoned. -- Joshdoe 15:41, 22 August 2011 (BST)
A case for contours, whether as OSM Ways or otherwise
OSM Way implementation: As an OSM Way, a contour line would be tagged something like:
- natural=contour
- ele=*
It should be arranged with the lower side to the right, like with cliffs, embankments and retaining walls. Should not share points with any other OSM objects, as no other objects are defined by their elevation values, except for natural=coastline which is essentially a contour line with ele=0.
Use cases: Contour lines would visualize terrain elevation on the www.osm.org map which currently lacks this feature. Embankments are represented on the default OSM map, but a circular hill - no matter how large and steep - is currently only represented by a single natural=peak point. Height contours could also be used to help decide at what zoom levels each natural=peak should be displayed - currently each peak appears at zoom level 11 regardless of its elevation compared to its surroundings and compared to nearby peaks.
Alternative to OSM Ways: Since they wouldn't connect to other OSM objects, contour lines might be best implemented as a separate layer, like Map Notes, Map Data, Public GPS Traces. Perhaps such data could be automatically downloaded from various government agencies, and only handled manually at country borders. --Waterhen (talk) 14:56, 25 May 2025 (UTC)