[talk-ph] areas of mangrove

[Totor]

Hi David,

I understood the coastline should be at the "mean high water spring".
The mangroves I have seen in the Philippines, were always outside that coastline, in the sea.
So I map them as in your method 2.

When tracing from low res or unclear sat imagery, i usually include the mangroves in the land area (because i dont know if it is a mangrove) but then I do not tag the mangrove at all. 

Just my opinion...

Cheers

Totor


On April 30, 2016 10:14:43 AM GMT+08:00, David Groom wrote:
>There are two different approaches used in mapping mangrove  areas in
>OSM
>
>1)  Treat the boundary of the mangrove and the openwater sea as the 
>coastline, and then map the area between that line and the "dry" land
>as 
>wetland.  This means that the wetland symbols are rendered over the 
>white colour of the land, and that at zoom levels 12 and lower the 
>mangrove areas simply get shown as white, with the sea outside them.
>
>2)  Treat the boundary of the mangrove and the "dry" land as the 
>coastline, and then map the area between that line and the openwater
>sea 
>as wetland.  This means that the wetland symbols are rendered over the 
>blue colour of the sea, and that at zoom levels 12 and lower the 
>mangrove areas simply get shown as blue sea.
>
>Early today I added some mangrove areas and followed approach 2 because
>
>the coastline had been accurately mapped along the mangrove / dry land 
>boundary, as so I simply added the mangrove area outside this, as it 
>seemed the existing mapper had cleary thought the coastline should be
>at 
>the dry land boundary.
>
>However at  http://www.openstreetmap.org/#map=14/9.7497/125.6105 both 
>these approaches have been used.  Approach 1  has been used for Lamagon
>
>Island, where the boundary of the mangrove area and the sea is tagged
>as 
>coastline.  But Approach 2 has been used for the island immeditately 
>south, where the boundary of the dry land is tagged as coastline.
>
>On further investigation I see at 
>http://www.openstreetmap.org/#map=14/9.7003/125.6415  that Approach 1 
>has been used.
>
>Has this issue been discussued before within the Philippine OSM 
>community, with any recommended way of mapping mangrove areas being 
>decided upon?
>
>Regards
>David
>
>
>
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