[Talk-us] Low-quality NHD imports

Clifford Snow clifford at snowandsnow.us
Sat Oct 14 02:56:59 UTC 2017

On Fri, Oct 13, 2017 at 10:34 AM, Christoph Hormann <osm at imagico.de> wrote:

> On Friday 13 October 2017, Kevin Kenny wrote:
> >
> > I remain unconvinced that importing or not importing has had any
> > significant impact on whether people improve the map manually.
> There are a number of possible measures that could be considered for
> improving old NHD imports:
> * removal of unnecessary tags to reduce the baggage mappers would have
> to deal with when working on the data.
> * removal of small unnamed streams which are not necessary for the
> overall river network connectivity in areas where the geometric
> accuracy is poor by current standards (and it is therefore usually
> easier for mappers to newly trace those streams instead of trying to
> improve the inaccurate data)

Unnamed streams are helpful to people hiking in the forest areas by giving
a landmark for navigation. From areas I'm familiar with, there are
thousands of unnamed streams. They are unnamed because civilization just
hasn't reached it. For example, we have Logan Creek nearby. If it was in a
national forest it would most likely be unnamed.

* creating maproulette challenges for fixing inaccurate waterway
> classifications - in particular waterways tagged 'waterway=stream' but
> with a name containing 'Creek' or 'River' will often qualify as
> waterway=river.  Same for artificial waterways with 'waterway=ditch'
> but names containing 'Canal' or ther other way round.

When I see creek in the name, it implies stream, at least in areas I'm
familiar with, then again that's where I usually map. I'm not sure where
you are from but I never consider telling you how to classify something
just by the name. A Maproulette could be handy if we had NHD classification
differences between what't tagged in OSM and NHD.

* creating maproulette challenges for unconnected waterways.


> * adding missing 'intermittent=yes' to waterways in imports where this
> was not properly set based on the feature codes.


OpenStreetMap: Maps with a human touch
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