<br />
<br />1698
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<br />OCTOBER 1973
<br />
<br />HY10
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<br />
<br />EXPLANATION
<br />Taylor ~ Yalloni' s data
<br />d'O.2151ll'1'
<br />Re.'9.6-1J.9
<br />D'O.lS-a.20ft
<br />_._1' 20.6 _ 21J "[
<br />_~J' 35.6 - 36.1'C
<br />
<br />Fqnco', data
<br />d'G.23om
<br />Re,-6.r- 11.6
<br />O'Q.4Z-0.67ft
<br />_.~T , 4.4 "[
<br />~T" 1~.60C
<br />__~I. = 26./ "C
<br />
<br />:t- 10
<br />n,OOI 0.01 fl.]
<br />IINJf SHlfMPD~IR, VS, iN FO01-PQUlJDSPER POUND PeR SECOND
<br />
<br />w'
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<br />8
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<br />.
<br />.
<br />
<br />FIG. 9.-RelationShip Between Measured Total Sediment Concentration and Unit
<br />Stream Power at Different Water Temperatures
<br />
<br />
<br />[ArLAN^IION
<br />
<br />~ . 0.4 ,."
<br />T-,O.C
<br />
<br />_"_On n - I].~ ((
<br />_110 n,l1 ft
<br />-.-D"l.~ft
<br />----D.2.0([
<br />
<br />10"
<br />10"1 10"
<br />IINTT ,1HAM PlIWrR. VS. I~ fOOT .POllNJS PER ~OUNn r[~ ,lcorm
<br />
<br />
<br />~IG. 10.-Effect of Variation of Water Depth on Predicted Total Sediment Concentra-
<br />tion by Eq. 26
<br />
<br />.
<br />
<br />HY10
<br />
<br />INCIPIENT MOTION
<br />
<br />total sediment concentration wirh d = 0.4 mm and T = 200 C. This figure
<br />indicates that total sediment concentration decreases with increasing water depth
<br />when the unir stream power is higher than a cerrain value. When the unit stream
<br />power is below a certain value, an increase of water depth causes an increase
<br />of the total sediment concentration. This phenomenon can be explained by
<br />the relationships among water depth, shear velocity Reynolds number, and the
<br />dimensionless critical velocity. An increase in depth causes an increase in the
<br />shear velocity Reynolds number, which in turn causes a decrease in the
<br />dimensionless critical velocity as shown in Fig. 3. The difference between VSjw
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<br />100
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<br />
<br />EXPLANATION
<br />
<br />SU!"',O,t,
<br />
<br />d-OA"",
<br />~e' . 18.J - ~9.8
<br />T-20.0-28.9"C
<br />n.!___ 0 . o.~ II
<br />-4.....0.0.8rt
<br />___0' LOft
<br />
<br />~
<br />~
<br />
<br />. MeaSlJred
<br />o EqlJation26
<br />
<br />1.0
<br />100 SOD 1000 2000
<br />WATERDISCI-lARGE,Q,INCUBICFEET
<br />PER SECON~
<br />
<br />w'
<br />/1O-J 10.2 10-1
<br />UNlT'.TREAMPO'.ER,VS.INrOOT-POUNOP[RPOUNOP[R'.[CDlJD
<br />
<br />FIG. 11.-Relationship Between Mea.
<br />suredTotal Sediment Concentration and
<br />Unit Stream Power at Different Water
<br />Depths
<br />
<br />FIG. 12.-Measured Total Sediment Dis.
<br />charge for Niobrara River Near Cody.
<br />Neb., Compared With That Computed by
<br />Vanoni, et al. Using Various Sediment
<br />Transport Equations. and With That
<br />Computed by Using Eq. 26
<br />
<br />and (VS - V <::rS)/w is not significant when the value of unit stream power
<br />is high. Consequently, total sediment concentration should decrease with increas-
<br />ing water depth as explained by Yang (40). However, at low values of unit
<br />stream power. a decrease of V C~/ w due to the increase of depth should cause
<br />a relatively signjfjcant increase of (VS - Vcr S) / w. This increase of (VS -
<br />V S) / w at low values of unit stream power should cause an increase of total
<br />sediment concentration. Data collected by Stein as shown in Fig. 11 seem to
<br />support the phenomenon indicated in Fig. 10.
<br />The effects of the variations of particle size, water temperature, and water
<br />depth on the predicted total sediment concentration in accordance with Eq.
<br />
<br />
|