My WebLink
|
Help
|
About
|
Sign Out
Home
Browse
Search
FLOOD09807
CWCB
>
Floodplain Documents
>
Backfile
>
9001-10000
>
FLOOD09807
Metadata
Thumbnails
Annotations
Entry Properties
Last modified
1/26/2010 10:10:38 AM
Creation date
10/5/2006 4:39:46 AM
Metadata
Fields
Template:
Floodplain Documents
County
Statewide
Community
Nationwide
Basin
Statewide
Title
A Uniform Technique for Determining Flood Flow Frequencies
Date
12/1/1967
Prepared By
Water Resources Council - Hydrology Committee
Floodplain - Doc Type
Educational/Technical/Reference Information
There are no annotations on this page.
Document management portal powered by Laserfiche WebLink 9 © 1998-2015
Laserfiche.
All rights reserved.
/
74
PDF
Print
Pages to print
Enter page numbers and/or page ranges separated by commas. For example, 1,3,5-12.
After downloading, print the document using a PDF reader (e.g. Adobe Reader).
Show annotations
View images
View plain text
<br />Table 2.--Factors that effect roughness of the channel <br />[Modified from Aldridge and Garrett, 1973, table 2J <br /> <br />Channel conditions <br /> <br />Example <br /> <br />n value <br />adjustmentY <br /> <br />Smooth <br /> <br />0.000 <br /> <br />Oompares to the smoothest channel attainable in a glven <br />bed material. <br /> <br />Minor <br /> <br />0.001-0.005 <br /> <br />Legree of <br />irregularity <br />(nl) <br /> <br />Moderate <br /> <br />0.006-0.010 <br /> <br />Compares to carefully dredged channels in good condition <br />but having slightly eroded or scoured side slopes. <br /> <br />Compares to dredged channels having moderate to con- <br />siderable bed roughness and moderately sloughed or <br />eroded side slopes. <br /> <br />'" <br /> <br />Severe <br /> <br />0.011-0.020 <br /> <br />Badly sloughed or scalloped banks of natural streams; <br />badly eroded or sloughed sides of canals or drainage <br />channels; unshaped, jagged, and irregular surfaces of <br />channels in rock. <br /> <br />Gradual <br /> <br />0.000 <br /> <br />Size and shape of channel cross sections change gradually. <br /> <br />Variation in <br />channel cross <br />section <br />(n2) <br /> <br />Alternating 0.001-0.005 <br />occasionally <br /> <br />Large and small cross sections alternate occasionally, or <br />the main flow occasionally shifts from side to side <br />owing to changes in cross-sectional shape. <br /> <br />Alternating <br />frequently <br /> <br />0.010-0.015 <br /> <br />Large and small cross sections alternate frequently, or <br />the main flow frequently shifts from side to side oWlng <br />to changes in cross-sectional shape. <br />
The URL can be used to link to this page
Your browser does not support the video tag.