[Tagging] Very large multipolygons

Frederik Ramm frederik at remote.org
Tue May 2 09:05:22 UTC 2017


   I have removed three very large multipolygons from OSM today.

* I DELETED a "place=sea" for the Adriatic Sea
(http://www.openstreetmap.org/relation/4590486) because I think we
shouldn't even start with that kind of thing (place=ocean name=Atlantic

* I CHANGED a "type=multipolygon, place=peninsula" to "type=boundary,
boundary=land_area" for the Italian Peninsula (

* I CHANGED a "type=multipolygon, place=region" to "type=boundary,
boundary=region" for the Alps
(http://www.openstreetmap.org/relation/2698607) even though I have a
feeling this should be deleted altogehter (the Alps are not an area as
sharply defined as this relation suggests).

I became aware of these because a while ago I've started including
cross-border multipolygons in the extracts I publish on
download.geofabrik.de, and these huge multipolygons are somewhat of a
disturbance, leading to the Switzerland extract containing the Danube
river in Vienna (which forms part of the "Alps" boundary), or the
Austria extract containing the outline of all of Italy because of the
"peninsula" multipolygon.

I realize that what I've done here is close to "mapping for the data
extractor" and I'm offering these decisions for discussion here. I
definitely think none of the three areas qualifies as a proper
"multipolygon" and *if* these huge areas need mapping, then some
solution based on "boundary" is better.


Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00'09" E008°23'33"

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