----- Original Message -----
From: "Elizabeth Dodd" <ed...@billiau.net>
To: <talk@openstreetmap.org>
Sent: Monday, March 21, 2011 10:19 PM
Subject: Re: [OSM-talk] the coastline
On Mon, 21 Mar 2011 21:59:20 -0000
"Andy Robinson" <ajrli...@gmail.com> wrote:
I'd place the coastline at the low water mark because you know then
that its always true. The coastline at the high water mark is only
true a couple of times a day or whatever. Then it needs a
high_water_mark way adding and ideally rendered in the long run.
Cheers
Andy
-----Original Message-----
From: Robin Paulson [mailto:robin.paul...@gmail.com]
Sent: 21 March 2011 21:46
To: OSM Talk
Subject: [OSM-talk] the coastline
i've recently been doing some mapping around auckland, adding coastal
walkways. one in particular i walked on sunday has two routes: one at
the foot of the cliffs, one on the road at the top of the cliffs. the
lower route is under water when the tide is in, so walkers are
advised to follow the road route.
so, i added the route, and it is now under water:
http://www.openstreetmap.org/?lat=-36.927322&lon=174.709115&zoom=18&layers=M
this seems wrong, drawing a route which is then under water, but the
alternative of moving the path is also wrong.
so, what do we do?
the question becomes (in my mind): why do we have a single way mapped
'coastline'? this implies the boundary between land and water is
static, but of course it moves - a number of times per day.
i like the possibility of a high water mark and a low water mark, used
together to entirely replace the natural=coastline tag.
perhaps some of you have some ideas around this also?
thanks,
--
the Coastline has been defined as high water mark.
http://wiki.openstreetmap.org/wiki/Tag:natural%3Dcoastline
I don't see that redefining it is going to be helpful
+ 1
Robin's point stands - should we mark the low water mark and the high
water mark and render the littoral zone differently?
I guess it is part of the micro-mapping initiative which is popular on
the tagging list.
There is a proposal at
http://wiki.openstreetmap.org/wiki/Proposed_features/Water_cover for water
= tidal, which defines the zone between low and high water
David
From a safety point of view, I'd rather know that the path is under
water. Then I can examine the coast and the tide tables (or ask) and
make a decision on walking it.
I certainly don't want a router taking me through there as the shortest
or fastest walk.
_______________________________________________
talk mailing list
talk@openstreetmap.org
http://lists.openstreetmap.org/listinfo/talk
_______________________________________________
talk mailing list
talk@openstreetmap.org
http://lists.openstreetmap.org/listinfo/talk
