[OSM-newbies] Fixing the Mississippi River
reviews at pacific-rim.net
Fri Sep 2 10:45:34 BST 2011
> ----- Original Message -----
> From: "Dan Ball" <danpelota at gmail.com>
> To: <newbies at openstreetmap.org>
> Sent: Monday, August 29, 2011 7:35 PM
> Subject: [OSM-newbies] Fixing the Mississippi River
> Hi all,
> I've been tinkering OSM data for the first time over the last week and
welcome to OSM.
> finding my way around. I've stumbled upon something interesting: the
> riverbank of the Mississippi River seems to be missing between Maxey
> and just south of Quincy, IL
> seems the missing riverbanks cause the river to "disappear" between these
> two areas on the openstreetmap.org viewer.
> I'd be happy to contribute if the data are indeed lacking here – I've just
> never edited OSM data and wanted to clarify a few things before I started
> messing with such a major geographic feature:
> 1) The source of the riverbank data appears to be NHD where the features
> on both sides. Should these features be connected by hand, or should this
> hydrography data be imported from elsewhere?
I'd guess that in this instance its easier and quicker to trace these from
the available aerial imagery
> 2) Does it matter whether the nodes are placed in a clockwise or
> counterclockwise matter?
Not really, though convention always was that outer ways got drawn
clockwise, and inner ways anti-clockwise, but this became unnecessary when
multpolygons started to be used
> 3) Should the addition be one multipolygon, or broken up into multiple
Definitely break this up into smaller sections. Its difficult to give any
hard and fast rules on how many small sections to break this into, but if
you have a look at the existing sections to the north and south of the
missing section, I'd say they look OK.
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