[Talk-ca] 001k - coastline

[Daniel Begin]

Hi all,

When you say 'ocean water polygons', I guess you are talking about modifying
natural=coastline ways (PGS or others) that define oceans among other things
using/for Canvec data?

I usually prefer to keep the original data and make it fits on the (assumed
better) reference data.  Furthermore, playing with natural=coastline feature
might be tricky - because it does not tolerate gap in it. 

So, except for 'river mouth', I would consider to alter the original
coastline by fitting it on Canvec features that define high water level.  

For intermittent water (reef, sand or other) I use the water cover proposed
feature http://wiki.openstreetmap.org/wiki/Proposed_features/Water_cover

- Read http://wiki.openstreetmap.org/wiki/Talk:Proposed_features/Water_cover
Unified proposition.

However, sometime it does not make sense because it is too complex/tedious!
We are doing that fun! aren't we?  

In such case - if the procedure above seems more complex than the following:

   
- Replace the coastline by the corresponding segment of the water polygon;
- Replace natural=water tag by natural=coastline;
- Make sure all coastline ways are linked/snapped together;
- Clean up the mess!

For river mouth - because the coastline should stop somewhere ...
I would clip the shoreline (and join the two segment together) before
replacing the river's shoreline with water polygon.

et bla,bla,bla ...

Cheers,
Daniel



-----Original Message-----
From: talk-ca-bounces at openstreetmap.org
[mailto:talk-ca-bounces at openstreetmap.org] On Behalf Of Sam Vekemans
Sent: July-09-10 01:22
To: Talk-CA OpenStreetMap
Subject: [Talk-ca] 001k - coastline

Hi all,
Thanks Daniel,
On the #osm-ca IRC we were trying to figure out the best solution for
'ocean water polygons'.

Its basically this, if the body of water is a 'bay' or 'river mouth'
or has 'reefs' or 'no flow coastal water', then we use the
natural=water polygon, and just smooth out the jagged edges.
Daniel did this on a more conservative way so its even better.

Its up for debate, and one of those things that we will notice after
the map is more complete.
Another option, is to streatch out the water, just as far as where the
'deep ocean' starts. We have a WMS layer which shows this.
This allows for the naming of these water areas.

Cheers,
Sam


-- 
Twitter: @Acrosscanada
Blogs: http://acrosscanadatrails.posterous.com/
http://Acrosscanadatrails.blogspot.com
Facebook: http://www.facebook.com/sam.vekemans
Skype: samvekemans
IRC: irc://irc.oftc.net #osm-ca Canadian OSM channel (an open chat room)
@Acrosscanadatrails

_______________________________________________
Talk-ca mailing list
Talk-ca at openstreetmap.org
http://lists.openstreetmap.org/listinfo/talk-ca