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<br /> <br />1698 <br /> <br />~ w' <br />i' <br />. <br />. <br />- <br />u <br />~ <br /> 1~2 <br />u <br />~ <br /> <br /> <br />OCTOBER 1973 <br /> <br />HY10 <br /> <br />_/,'JiJ.. <br />/,/ <br />1/ <br />.1/ <br />// <br />f <br />,l'p { <br />/; <br />, . <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' <br /> <br />.. <br />" <br />" <br />, <br />~e <br />- <br />.. 10J <br />8 <br />, <br />.- <br />~ <br />- <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 <br /> <br />,,' <br /> <br /> <br />100 <br /> <br />o <br />, <br />o <br />~ <br />" <br /> <br /> <br />~ <br />. <br />. ,,' <br />, <br />" <br />! <br />~ <br />! <br />. ,,' <br />~ <br />, <br />1 <br /> <br />100 <br /> <br />//" <br />.{ <br />../:L <br />,f <br />f':/ <br />.r.t' <br />L:if. <br />.' <br />.' <br />.F <br />//,' <br />~ <br />/ <br />.I <br /> <br />o <br />, <br />o <br />o <br /> <br />~ <br /> <br />[XPLANilT10N <br /> <br />~ <br />~ <br />~ <br />, <br />~ <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 />