[OSM-dev] Coastline generalization tool and data

[Christoph Hormann]

On Thursday 14 February 2013, Stefan Ziegler wrote:
>
> If you look at the island Usedom in the Baltic Sea (Northeast
> Germany, near Poland): it is connected to mainland. Usedom is really
> difficult with small stripes of water between island and mainland.

That's right.  Since it is a raster based process only structures large 
enough to be resolved in the raster will be taken into account.  The 
Peenestrom misses the cutoff by a small distance here.

A possible solution would be to distinctly tag such waterways, in this 
case:

http://www.openstreetmap.org/browse/way/102832340

with something like waterway=strait and then consider those in addition 
to the coastline itself during generalization.

Usedom however is currently no real island in OSM anyway since only one 
side is tagged as coastline:

http://www.openstreetmap.org/browse/way/174336199
http://www.openstreetmap.org/browse/way/7724629

-- 
Christoph Hormann
http://www.imagico.de/