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 > > > >_______________________________________________ >talk-ph mailing list >[email protected] >https://lists.openstreetmap.org/listinfo/talk-ph _______________________________________________ talk-ph mailing list [email protected] https://lists.openstreetmap.org/listinfo/talk-ph
