Re: [OSM-talk] the coastline
to the list as well On 22 Mar 2011 16:58, "Kevin Peat" wrote: > > > On 22 Mar 2011 10:41, "David Groom" wrote:> > >> > >> 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 > > I have used tidal=yes to mark the tidal parts of beaches, rivers, paths, etc. It has ~5000 uses per taginfo so I guess other people are using it as well. > > Kevin ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] the coastline
- Original Message - From: "Elizabeth Dodd" To: Sent: Monday, March 21, 2011 10:19 PM Subject: Re: [OSM-talk] the coastline On Mon, 21 Mar 2011 21:59:20 - "Andy Robinson" 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
Re: [OSM-talk] the coastline
On Mon, Mar 21, 2011 at 5:45 PM, Robin Paulson wrote: > 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? I don't have a solution but I certainly admire the problem. To complicate things, while maps may show mean high-water, borders seem to be mean low-water. WIkipedia says so. Adjusting a coastline polygon based on aerial imagery will get us something in between. Or something not-between because mean high-water is a mean. So that's all really bad and difficult to map. How about extending intermittent=yes from rivers and streams to footways as well? It would take an advanced router to know to look for intermittent=yes to avoid that path for the walker less likely to check conditions for themselves. Perhaps highway:intermittent=footway so that the intermittent footway fails to be found by tools that aren't aware footways can be intermittent? ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] the coastline
On 21 Mar 2011, at 21:59, Andy Robinson 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. Depending on your definition of "true" – you used the definition "everything outside the coastline mark is water", and by that definition it is indeed true. Equally valid though is "everything inside the coastline mark is land", and that's only true a couple of times a day if you put it at low water, while it's always true if you put it at high water. The proposal for both a high water mark and a low water mark seems ideal to me – though hard to gather data for. My guess is that the current data marks high water though, given that that's what's typically marked on most map serieses. Bob ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] the coastline
On 21-3-2011 22:59, Andy Robinson wrote: I'd place the coastline at the low water mark because you know then that its always true. Do you know what happens just before a tsunami hits land? -- Lennard ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] the coastline
On Mon, 21 Mar 2011 21:59:20 - "Andy Robinson" 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
Re: [OSM-talk] the coastline
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, -- robin http://tangleball.org.nz/ - Auckland's Creative Space http://openstreetmap.org.nz/ - Open Street Map New Zealand http://bumblepuppy.org/blog/ ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
[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, -- robin http://tangleball.org.nz/ - Auckland's Creative Space http://openstreetmap.org.nz/ - Open Street Map New Zealand http://bumblepuppy.org/blog/ ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
