[talk-au] natural=land v natural=coastline

James Livingston doctau at mac.com
Tue Oct 6 14:55:07 BST 2009

On 06/10/2009, at 11:37 PM, Jim Croft wrote:
> Of course, this won't work for mariners and lawyers... :)

No, but there are (proposed) tags to indicate the low-tide mark, and  
the OpenSeaMap guys might have something for other various maritime  

> My favourite estuary is the Fly River in PNG.  It just gets gradually
> wider and wider and wider.  Somewhere the river becomes the ocean.
> And there is no way to tell where it happens...

Yep, the problem with saying "where the tidal effect are no longer  
significant" or "where fresh and sea water meet" is that they're  
continuous, so you need some arbitrary limit.

I'd say the only definite boundary would be to take the convex hull of  
the land mass. Of course, that means the Great Australian Bight would  
be a river, along with the Gulf of Carpentaria and the similar places  
and the like.

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