[Talk-us] US Hydrographic Data

Ian Dees ian.dees at gmail.com
Fri May 2 21:41:02 BST 2008


According to the 105th page of the first PDF of specs on
http://rockyweb.cr.usgs.gov/nmpstds/nhdstds.html, they use 1D linear
features for rivers when the river is too small to represent as a 2D area.
There is a relatively large set of rules that they used to determine the
size.

Also, if there are names are known (but not included in the data), then we
should add them using the GNIS interface at http://nhd.usgs.gov/gnis.html.

On Fri, May 2, 2008 at 2:38 PM, Adam Schreiber <sadam at clemson.edu> wrote:

> On Fri, May 2, 2008 at 3:21 PM, Ian Dees <ian.dees at gmail.com> wrote:
> > The NHD viewer (http://nhdgeo.usgs.gov/viewer.htm) shows areas for
> rivers
> > that are "big enough" (I see areas for the Mississippi, for example).
> >
> > I haven't tried converting an area that has such a river yet, but I'll
> bet
> > the script handles it.
>
> In my sub-basin, 03060101, there's a section of the Seneca River
> that's at least 50-100 m that's shown as a linear feature.  I'll
> attach a screenshot with the NHD data in white, the landsat image and
> the TIGER data in grey.  I've also noticed that at least two lakes in
> the sub-basin are missing names.  I don't have an appropriate
> application installed to view the shape file directly to see if they
> are included there.
>
>
> Cheers,
>
> Adam
> >
> > On Fri, May 2, 2008 at 1:17 PM, Adam Schreiber <sadam at clemson.edu>
> wrote:
> > > Is there a reason the NHD treats rivers as linear features instead of
> > > areas?  Is area data present for the river banks that isn't being
> > > converted yet?
> > >
> > > Cheers,
> > >
> > > Adam
> > >
> > >
> > >
> > >
> > > On Fri, May 2, 2008 at 9:46 AM, Ian Dees <ian.dees at gmail.com> wrote:
> > > > Tiles at Home is starting to show the data I uploaded yesterday:
> > > >
> > > > http://tah.openstreetmap.org/Browse/?x=1971&y=2935&z=13&layer=tile
> > > >
> > > > It looks like the water bodies aren't given "name" tags.
> > > >
> > > >
> > > >
> > > > On Thu, May 1, 2008 at 2:17 PM, Ian Dees <ian.dees at gmail.com> wrote:
> > > >
> > > > > I'm 80 minutes away from finishing an import in this area:
> > > > >
> > > > > http://tah.openstreetmap.org/Browse/?x=245&y=367&z=10&layer=tile
> > > > >
> > > > > I'll probably have to "fill in the holes" for islands and maybe
> slice
> > up
> > > > the extra-long ways (both are TODOs on Matthew's python script I
> think).
> > > > >
> > > > >
> > > >
> > > >
> > >
> > >
> > >
> > > > _______________________________________________
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> > > >
> > > >
> > >
> >
> >
>
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