-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 natural=marsh? (from Map Features)
I would expect to find coastline on the open-sea border of this. Mark Mike Collinson wrote: > I agree with Stephen's comments and add that I follow the rule "if in doubt, > map it as land" since we don't have the luxury of being able to map average > high water marks or highest spring tide mark that a government agency might > use. If it is something that I can walk out and see most of the day or year, > then I think it should be mapped as land as a navigation aid. > > It might also be worth considering a natural=mangrove area tag. Our current > system is biased towards temperate climates. I've hesitated so far as it is > often very difficult, either on the ground or from imaging data, to map the > inland extent. > > Mike > > At 03:27 AM 9/07/2008, Stephen Hope wrote: >> The northern coast of Australia has many Mangrove marshes at river >> mouths, some of them extending many kilometres away from the dry shore >> line. PGS shows these areas as sea, because they are not dry land - >> and that is were the coastlines would have been imported from. Note >> that "being submerged for half the year" doesn't mean the trees are >> covered with water, just the mud under them. The tree tops would be >> above water all the time, I suspect. >> >> We've (mostly) tagged them as land, with the coast being on the sea >> side of them. Technically they may be water covered (or partially >> water covered, usually about 6 inches deep), but if you can't swim or >> boat in them and plants and trees grow there it's land as far as I'm >> concerned. They certainly are not ocean. Marshes in the UK are also >> treated as land from the coastline point of view, even were they edge >> an ocean. >> >> See >> http://www.openstreetmap.org/?lat=-16.9642&lon=145.7843&zoom=13&layers=B00FTF >> for an example near Cairns. More examples are further up the coast. >> >> Stephen >> >> >> 2008/7/9 Alan Millar <[EMAIL PROTECTED]>: >>> I came across an interesting area which I don't know how to map or tag. >>> >>> http://www.openstreetmap.org/?lat=22.066&lon=89.047&zoom=9&layers=B00FTF >>> >>> This is the Sundarbans mangrove forest on the border of India and >>> Bangladesh. The map doesn't look like much, but look at the map with >>> aerial photos like in Potlatch edit mode and it starts to get interesting. >>> >>> I read that it is submerged for up to half of the year. The Yahoo aerial >>> photos clearly show the forest areas, so I assume they were taken at a >>> low-water period. Google Maps shows it as land. >>> >>> Our oceantiles file has it as land, but our coastlines treat it as sea. >>> Our coastlines stop at the farmlands which border it. During the high >>> water period, I suppose our coastlines make sense. >>> >>> Does anyone have any recommendations of how to treat an area like this? >>> Any similar geography already mapped somewhere? Thanks >>> >>> - Alan >>> >>> >>> >>> ________________ -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFIdSv1JfMmcSPNh94RAty+AJ9voJsnb9ym6eiFMB9dNJFaHg5WpACfUWAO we9MgNpK8v5miRbnCw+4tU4= =tGCg -----END PGP SIGNATURE----- _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
