[OSM-talk] help with coastline

[Rob Reid]

Ulf Mehlig wrote the following on 01/05/2008 08:47:
> Hello openstreetmap experts,
>
> I tried to add a few details to a segment of the coastline of northern
> Brazil, but as I see today on Mapnik this caused some disorder in the
> coastline rendering (it looked almost ok in the slippy map/Osmarender,
> though).
>
> I would appreciate if one of the more experienced coastliners could help
> me to find the error(s) -- I'm stuck at the moment!
>
> The area in question is 
>
> http://www.openstreetmap.org/?lat=-0.9293&lon=-46.6796&zoom=12&layers=B0FT
>
> Many thanks in advance (and sorry for the mess ...)
> Ulf
>   
I spotted some of this yesterday on the coastline error checker and 
tried to fix a few bits.
The api seems to be down at the moment so I can't confirm exactly which 
bits I did but the main problem I found was what you had done at river 
mouths.
The main coastline way coming along the coast and across the river mouth 
was ok but the way around the river mouth was tagged as 
natural=coastline as well as waterway=riverbank.
One of the rules with coastline is that they can't fork so the orphan 
bit  of coastline around the mouth is causing problems I think. What I 
did with most of the ones I found was leave the main coastline as it was 
and change the way for the river mouth to be natural=water and make sure 
it was closed. I used this tag as I'm not sure an unclosed riverbank way 
works with all the renderers yet.

Cheers

rcr