On Wed, Apr 4, 2018 at 7:40 AM, Eugene Alvin Villar <sea...@gmail.com> wrote: > On Tue, Apr 3, 2018 at 9:22 PM, Martin Koppenhoefer <dieterdre...@gmail.com> > wrote: >>u >> the coastline should represent the limit of the sea, in case of a river >> flowing in, people look at the level of salt in the water and whether the >> level of the river is influenced by tides (afaik) > > > It seems some mappers go to the extreme opposite and map the coastline > across the mouth of an estuary that is clearly part of the ocean: > > https://www.openstreetmap.org/way/186710973
How something is called and thought of by the locals is also taken into account. Example: The Hudson River is hard to draw a firm boundary on. If one were to take the position that "any shoreline with a measurable tide is part of the coastline," then the coastline extends all the way up to the Federal Dam in Troy, New York: https://www.openstreetmap.org/way/90929525 It's still obviously a river up there. The water is fresh, and flows quite strongly in one direction. (When the tide is rising, it flows a little less strongly. It never reverses.) Drawing the salt front would be ambiguous by tens of km. In a wet season, its a highly diffuse front near the entrance to the Tappan Zee (note to self: make a relation for the waterbody!) https://www.openstreetmap.org/way/318106482 but in a drought it can retreat as far as the Poughkeepsie Bridge https://www.openstreetmap.org/way/24185107 or even farther. Even where it's brackish, it's still called a 'river,' and if you said that it was 'coastline,' the locals would look at you as if you had two heads. People seem to agree that the piers in Manhattan where the big ships dock are on the coast, so the line is drawn somewhat arbitrarily north of Spuyten Duyvil https://www.openstreetmap.org/way/135719690. I'm not going to say that the local mappers are wrong, even though the estuary is deep enough that vessels of considerable draft can sail into Albany. There's a WW2-vintage destroyer moored there on more-or-less permanent display. She got there under her own steam. In historic times, the Albany riverfront would display a small forest of ships' masts - but it's always been called a riverport, not a seaport. A sailing vessel would have to kedge the faster sections of the river. I pity those who had to man the capstan. _______________________________________________ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
