[OSM-talk] the coastline
tom.davie at gmail.com
Mon Mar 21 22:36:20 GMT 2011
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.
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