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<br />Figure 9 shows the relationship between the original failure hydrograph and <br />the routed hydrograph at the end of the first typical reach. <br /> <br />cfs (IOOO) <br /> <br />5 <br /> <br /> <br />Op=13728 <br /> <br />-, OR= 11440 <br />, <br />, <br />\ <br />\ <br />\ <br />\ <br />\ <br />, <br />, <br />, <br />"':..--- <br /> <br />Hrs <br /> <br />10 <br /> <br />o <br /> <br />0.5 <br /> <br />1.0 <br /> <br />1.5 <br /> <br />Figure 9; Hydrograph COmparison. Before and After Routing <br /> <br />As previously discussed. it is not necessary to fully create the routed <br />hydrograph. as long as its peak value can be determined. For the example: <br /> <br />Qri maximum = Qr14 = 11440 CFS <br /> <br />by multiplication of the maximum values of the two vectors. This term is <br />the application of equation 16. also shown at the bottom of Worksheet W-2. <br /> <br />using Qri and Manning's equation. the depth of flow at the end of typical <br />reach 1 (Dl) is calculated as 17.3 feet. <br /> <br />Qr2 and D2 values are calculated for the second typical reach by using <br />the peak of the routed hydrograph. computed for the end of the first reach <br />(Qrl). Without significant loss of accuracy. the routed hydrograph of the <br />first reach can be assumed again to be of triangular shape. with base time <br />Tri given by rearrangement of equation 1. <br /> <br />Tri = 24.2 V <br />Qri <br /> <br />where V is reservoir volume in acre feet. Figure 10 shows the effect of the <br />assumption. <br /> <br />14 <br />