[Tagging] Tidal inlets / creeks

[charlie at cferrero.net]

Malcolm Herring (malcolm.herring at btinternet.com) wrote:

> On 18/01/2011 12:44, charlie at cferrero.net wrote:
>>
>> It would be nice to be able to map the tidal waterways that run in
>> between the mangroves and saltmarshes - particularly the manmade ones
>> that have been explicitly cleared to allow marine vessels. Unfortunately
>> I can't see any way of tagging a waterway that does not imply
>> freshwater. Ideally we'd have a waterway=tidal_creek or something like
>> that but this doesn't seem to be in use at all.
>>
> A way tagged natural=coastline should follow the local mean *high*  
> water level so that all tidal areas will be on the wet side of the  
> way. Any tidal areas (wetlands of all types, beaches, mud, etc) can  
> be mapped as closed polygon ways that enclose areas above the local  
> mean *low* water level. These areas will be rendered at the higher  
> zoom levels. Navigable channels that exist between these areas will  
> then have been left as non-tidal (i.e. always wet)
>>
Thanks.  I understand what you're suggesting, and I was probably a bit  
misleading in my original email.  The problem is how to differentiate  
between sub-low-water level areas that are 2m deep, and the (often  
man-made) channels that are sufficiently deep to allow navigation.

-- 
Charlie