|
<br />
<br />1686
<br />
<br />(1)
<br />0.2053
<br />0.347
<br />0.347
<br />0.347
<br />0.4828
<br />0.4828
<br />0.4~28
<br />0.5056
<br />0.5056
<br />0.5056
<br />0.5246'
<br />0.5246"
<br />0.5246"
<br />0.52461>
<br />0.52461>
<br />0.5246'
<br />0.5409
<br />0.5409
<br />0.5409
<br />0.5861
<br />0.5861
<br />0.5861
<br />4.0769
<br />4.0769
<br />4.0769
<br />
<br />OCTOBER 1973
<br />TABLE 1.-Continued
<br />
<br />(2)
<br />0.0020
<br />0.0010
<br />0.0015
<br />0.0020
<br />0.0010
<br />0.0015
<br />0.0020
<br />0.0010
<br />0.0015
<br />0.0020
<br />0.0010
<br />0.0015
<br />0.0020
<br />0.00 10
<br />0.0015
<br />0.0020
<br />0.0010
<br />0.0015
<br />0.0020
<br />0.0010
<br />0.0015
<br />0.0020
<br />0.0030
<br />0.0040
<br />0.0045
<br />
<br />(31
<br />2.62
<br />5.41
<br />5.08
<br />6.27
<br />7.60
<br />7.42
<br />7.55
<br />8.17
<br />8.08
<br />8.84
<br />8.31
<br />9.34
<br />8.76
<br />10.05
<br />9.38
<br />9.89
<br />11.34
<br />11.92
<br />12.30
<br />12.11
<br />11.06
<br />11.54
<br />184.18
<br />188.38
<br />195.25
<br />
<br />(4)
<br />8.060
<br />5.905
<br />5.038
<br />5.261
<br />4.044
<br />3.918
<br />3.637
<br />3.957
<br />3.644
<br />4.130
<br />3.828
<br />3.314
<br />3.552
<br />3.308
<br />3.232
<br />2.907
<br />3.275
<br />3.114
<br />3.014
<br />3.610
<br />2.990
<br />2.990
<br />1.852
<br />1.746
<br />1.814
<br />
<br />KChanncl width = 2.313 ft (70.5 em).
<br />bChnnncl width = 2.416 ft (73.64 em).
<br />
<br />Gilbert's "several grains moving" (6), Kramer's "weak movement" (13), U.S,
<br />Waterways Experiment Station's "weak movement" (27), and Yanoni's "critical
<br />movement" (31). the average velocity was not published by Tison; rather, it
<br />was computed by using his Eqs. 4 or 6. When more than one observation
<br />was made under similar flow and sediment conditions, the average value is
<br />used in the analysis. These data are summarized in Table 1 and plotted on
<br />Fig.3.
<br />As shown in Fig. 3, when the shear velocity Reynolds number is smaller
<br />than 70, the data follow thc hypcrbola
<br />
<br />v"
<br />
<br />w
<br />
<br />HY10
<br />
<br />INCIPIENT MOTION
<br />
<br />(51
<br />1
<br />1
<br />1
<br />I
<br />3
<br />2
<br />4
<br />3
<br />1
<br />3
<br />2
<br />3
<br />3
<br />2
<br />2
<br />2
<br />2
<br />3
<br />3
<br />5
<br />2
<br />2
<br />3
<br />3
<br />4
<br />
<br />'"I -~-TrITTT-------r III
<br />I
<br />"I
<br />"I-
<br />I
<br />
<br />I I III r---T-'T--rnl
<br />"",.....,,,.
<br />,,,.,
<br />'om".b".,,,,
<br />
<br />""'" 1
<br />lL,,"
<br />""'"'
<br />'.""''''''',,'''m'.'
<br />''',""0 --
<br />
<br />l
<br />i
<br />..J
<br />
<br />-~-1
<br />1
<br />-1
<br />
<br />t'
<br />.)
<br />~
<br />~
<br />n
<br />l'
<br />-1:$
<br />
<br />,,'>-
<br />i
<br />i
<br />,,,1_...
<br />
<br />~~'I .
<br />
<br />,,,,",,,. -+----~T...."Tr.)N
<br />,
<br />,
<br />,
<br />,
<br />,
<br />I
<br />'[' ~:, i
<br />L. I
<br />,- I ~$(. ('-:!.-'~~;;-,"" ---1
<br />I I ""~~.--'---- I ',,"0":
<br />,__ f,,, .,~ ": ' -, "..l...-..~
<br />I .
<br />n___L.....LL1.1illL_--L_L.Llllm .L .L, llJJli
<br />, '" I~
<br />
<br />
<br />~il" '''0'''' "".Jlb\ ,,,,,,roo '" . ":'
<br />
<br />FIG. 3.-Relationship Between Dimensionless Critical Velocity and Shear Velocity
<br />Reynolds Number at Incipient Motion
<br />
<br />; w4
<br />,
<br />
<br />2.Qlut,., (,!lij L!l'i!'i'~ nAIA
<br />.,TRAIGHlrllll/llif.l I /"
<br />~M!ANLJHINGTH^LW(G ~-
<br />4BAAIOln WMlUll ,-
<br />/.".Ii. _
<br />/'
<br />"
<br />
<br />~"y
<br />/'
<br />
<br />
<br />~ 10)
<br />
<br />2.5
<br />
<br />(U,d)
<br />log ---;;- - 0.06
<br />
<br />+ 0.66,
<br />
<br />U.d
<br />o < - < 70 . . . . , . . . . . . , (18)
<br />v
<br />
<br />~: I~< III') IP" 1<),1
<br />''''L1IH IINIT \1I'rM rOWlfl, v'._v 1'\' I~ Ilm-r":II'." "I~ rDlFN~ rF. "(["'11
<br />
<br />fairly weB, as they should in accordance with Eq. 15. The correlation coefficient
<br />and standard error of estimate between observations and Eq. 18 are 0.955 and
<br />0.513, respectively. The coefficients used in Eq. 18 were determined by trial
<br />and error to minimize the deviation between the observed and predicted values.
<br />When the shear velocity Reynolds number is greater than 70, V c;r/ w is no longer
<br />
<br />FIG. 4.-Relationship Between Total Sediment Concentration and Effective Unit
<br />Stream Power During Process of Channel Pattern Development From Straight to
<br />Meandering, and To Braided
<br />
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