-------- Original Message --------
Subject: Re: USGS Topos - Blue Line Stream Designations
Date: Thu, 31 May 2007 01:13:03 GMT
From: [log in to unmask] <[log in to unmask]>
To: [log in to unmask]
CC: [log in to unmask]
Are you meaning double-line streams? At the 1:100,000 scale it's
200 ft.
100000 * 0.008" * 3 (apparently the thinnest pen width) = 2400 inches
= 200 feet
So presumably a single-line stream is 66 ft.
As I recall, the calculations are similar for 1:24000 scale.
http://rockyweb.cr.usgs.gov/nmpstds/acrodocs/core3/2CR30197.PDF
The 1:100K standards are worded slightly differently -- you have to
order the hardcopy version.
http://rockyweb.cr.usgs.gov/nmpstds/omapstds.html
Joe McCollum
Forest Inventory and Analysis
Knoxville, TN 37919