[Tagging] Tagging Digest, Vol 121, Issue 97

Michael Patrick geodesy99 at gmail.com
Sat Oct 26 08:01:49 UTC 2019


> Looking at the US NHD estuary is broadly defined

NOAA keeps track of the estuaries. And the states have fairly extensive
data available:
https://www.coastalatlas.net/?option=com_jumi&view=application&fileid=8&e=20&Itemid=107

Estuary is a generic term that covers five basic types, which have quite
different in the characteristics that define them, beyond the general
'river going into the see' aspect. A Norwegian fjord and a mudflat can both
be estuaries. Once you identify the type ( and since they are hugely
important to global fisheries and other stakeholders, almost certainly
someone has already identified the type
https://oceanservice.noaa.gov/education/kits/estuaries/estuaries04_geology.html
), how the various feature boundaries are to be handled in OSM isn't too
difficult.

The ocean edge of the estuary if defined by if it is tide-dominated,
wave-dominated, or river-dominated. That determines if you have have a Bay
of Fundy https://en.wikipedia.org/wiki/Bay_of_Fundy estuary, Bay of Fundy,
a Mississippi River type of delta, or a Columbia River situation where the
river channel pretty much extends to the sea. That can be generally
indicated in a tide table according to three basic buckets >4 meters, 2-4
meters, and less than 2 meters.

>>>> but I think we'll have problems defining it?

Only if you try to make the same scheme apply to all five ( coastal plain
<https://oceanservice.noaa.gov/education/kits/estuaries/media/supp_estuar04_coastal.html>,
bar-built
<https://oceanservice.noaa.gov/education/kits/estuaries/media/supp_estuar04_barbuilt.html>,
deltas
<https://oceanservice.noaa.gov/education/kits/estuaries/media/supp_estuar04_delta.html>,
tectonic
<https://oceanservice.noaa.gov/education/kits/estuaries/media/supp_estuar04_techtonic.html>
and fjords
<https://oceanservice.noaa.gov/education/kits/estuaries/media/supp_estuar04_fjord.html>
).

The 'cartographic' derived concept that there is just some sort of simple
idealized 'coastline' is a fiction, and at the scale of human beings, not a
very useful one. There isn't land and sea, there is land, sea, and a third
'coastal', which is land and sea changing several times a day and
dramatically on a monthly and annual basis.

Michael Patrick
Data Ferret
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/tagging/attachments/20191026/7553f5ec/attachment.html>


More information about the Tagging mailing list