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 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. >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