My WebLink
|
Help
|
About
|
Sign Out
Home
Browse
Search
FLOOD03929
CWCB
>
Floodplain Documents
>
Backfile
>
3001-4000
>
FLOOD03929
Metadata
Thumbnails
Annotations
Entry Properties
Last modified
1/25/2010 6:44:46 PM
Creation date
10/5/2006 12:12:05 AM
Metadata
Fields
Template:
Floodplain Documents
County
Statewide
Community
Nationwide
Basin
Statewide
Title
Generalized Computer Program Fluvial-12 Mathematical Model for Erodible Channels Users Manual
Date
8/1/1986
Prepared By
Howard H. Chang, Ph.D., P.E.
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.
/
91
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 />Sediment transport, in the presence of transverse flow, has a component <br />in that direction. Sediment movement in the transverse direction contribu- <br />tes to the adjustment of transverse bed profile. In an unsteady flow, the <br />transverse bed profile varies with time, and it is constantly adjusted <br />toward equilibrium through scour and deposition. The transverse bed load <br />per unit channel length %' can be related to the streamwise transport %. <br />Such a relationship by Ikeda (1982) can be written in parametric fOIll1 as <br /> <br />'3b' ~ dZ) <br />-=F tan$,-- <br />'3b tJ r <br /> <br />(14) <br /> <br />where S is the angle of deviation of bottom currents from the streamwise <br />direction. The near-bed transverse velocity is a function of the curvature, <br />and it is canputed using the flow curvature. <br /> <br />Eq. 14 relates the direction of bed-load movement to the direction of <br />near-bed velocity and transverse bed slope dz/3r. As transverse velocity <br />starts to move sediment away from the concave bank, it creates a transverse <br />bed slope that counters the transverse sediment movement. An equilibrium is <br />reached, i.e., '3b' = 0, when the effects of these opposing tendencies are in <br />balance. Transverse bed-profile evolution is related to the variation in <br />bed-material load. Ikeda and Nishmura (1986) developed a method for <br />estimating transport and diffusion of fine sediments in the transverse <br />direction by vertical integration of suspended load over the depth. Their <br />model for predicting the transverse bed slope is also employed. <br /> <br />Changes in channel-bed elevation at a point due to transverse sediment <br />movement are comJ;Uted using the transverse continui ty equation for sediment <br /> <br />dZ <br />)t <br /> <br />1 1 d <br />+------ <br />1 - 11. r (Jr <br /> <br />(r lls') = 0 <br /> <br />(15) <br /> <br />written in finite difference form with a forward difference for qs', this <br />equation becomes <br /> <br />c.t <br />L::,.zk = ----- <br />1-). <br /> <br />r q' r q' <br />2 ~:t!_~~:!:1_=__~__~~ <br />rk rk+l - I:k-l <br /> <br />(16) <br /> <br />where k is the radial (transverse) coordinate index measured from the center <br /> <br />21 <br />
The URL can be used to link to this page
Your browser does not support the video tag.