[OSM-talk] Timezones (was: Deleting data)

Clifford Snow clifford at snowandsnow.us
Tue Oct 22 14:52:04 UTC 2013


On Tue, Oct 22, 2013 at 7:11 AM, Martin Koppenhoefer <dieterdreist at gmail.com
> wrote:

> It really depends on the legal situation, sometimes sharing nodes is the
> right thing to do (if the boundary is defined as being the river for
> instance), sometimes it is to be seen distinctly (when the boundary is
> defined by independent coordinates). In other cases it is even worse as
> there are several "official" versions for the same boundary ;-) (in the
> case of disputed boundaries, there are more cases than you might think).


Just because the boundary is defined being the road, doesn't mean the nodes
should be shared. The boundary may be aligned with a river or road, but not
necessarily connected. Connecting a boundary or landuse to a road or river
serves no useful purpose other than making it easy to add. But difficult to
change later. I would be very happy if the editor complained if a mapper
tried to connect roads/rivers and boundaries and landuse areas.

As was pointed out, borders may originally be defined as a river or road,
but once defined the river and road can easily change while the border
remains the same. For example here is an excerpt from Wikipedia:

"In March 1876, the Mississippi suddenly changed course near the settlement
of Reverie, Tennessee <http://en.wikipedia.org/wiki/Reverie,_Tennessee>,
leaving a small part of Tipton County,
Tennessee<http://en.wikipedia.org/wiki/Tipton_County,_Tennessee>,
attached to Arkansas <http://en.wikipedia.org/wiki/Arkansas> and separated
from the rest of Tennessee <http://en.wikipedia.org/wiki/Tennessee> by the
new river channel. Since this event was an
avulsion<http://en.wikipedia.org/wiki/Avulsion_(river)>,
rather than the effect of incremental erosion and deposition, the state
line remains located in the old
channel.[24]<http://en.wikipedia.org/wiki/Mississippi_River#cite_note-Arkansas_v._Tennessee.2C_246_U.S._158-24>
"

When boundaries are tied to roads or rivers, a mapper could move both even
though only the road or river changed.


-- 
Clifford

OpenStreetMap: Maps with a human touch
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