-------- Original Message --------
Subject:        Re: USGS Topos - Blue Line Stream Designations
Date:   Wed, 30 May 2007 14:28:41 -0400
From:   Jeff Essic <[log in to unmask]>
To:     Maps, Air Photo & Geospatial Systems Forum <[log in to unmask]>



Bill,

There may be specifications, but I think it basically came down to the
discretion of the photo-interpreter.

NC has done a lot of analysis of the inaccuracies of these stream
lines in preparation for our stream mapping program.

http://www.ncstreams.net/ is the program's website, but there's a lot
more content and information in various powerpoints you can find by
searching google for nc stream mapping.

Jeff


_______________________________________
Jeff Essic, Data Services Librarian
North Carolina State University
D.H. Hill Library, Research & Information Services
Box 7111, Raleigh, NC  27695-7111
http://www.lib.ncsu.edu/gis
(919) 515-5698




On 5/30/07, Maps-L <[log in to unmask]> wrote:
> -------- Original Message --------
> Subject:        USGS Topos - Blue Line Stream Designations
> Date:   Tue, 29 May 2007 14:20:43 -0700
> From:   A'Hearn, William <[log in to unmask]>
> To:     <[log in to unmask]>
>
>
> Does anyone know what is (was?) the criteria used by USGS to delineate a "BLUE-LINE" stream on USGS topo maps?  We have searched through USGS's website and Googled it to no avail.
>
> -- Bill A'Hearn
>
> Ø Ø Ø Ø Ø Ø Ø Ø Ø Ø Ø
>
> Bill A'Hearn, LSIT
> GIS Analyst/Mapping Specialist
> PW Engineering
> Mapping & GIS Services
> City of Glendale, CA
> [log in to unmask]
>
> Latitude: 34º 8' 48"N - Longitude: 118º 14' 49"W - Elev: 565'
>
> Ø Ø Ø Ø Ø Ø Ø Ø Ø Ø Ø
>
> "The good cartographer is both a scientist and an artist.  He must have a thorough knowledge of his subject and model, the Earth.... He must have the ability to generalize intelligently and to make a right selection of the features to show. These are represented by means of lines or colors; and the effective use of lines or colors requires more than knowledge of the subject - it requires artistic judgment."   Erwin Josephus Raisz (1893-1968)
>