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APPENDI\ U <br />Flood Routing Prop,ram <br />Equations: <br />tl = <br />L0.8(S+1)0.7 <br />1S00 <br />tP = tL + D/2 <br />q = 484A <br />P <br />t <br />P <br />tc = tL /0.6 <br />Q(t) _ (P(t) - 0.2 S)2 for P(t)a0.~2S <br />(P(t) + 0.8 S) <br />`~ Q(t) = 0 <br />P(t) DR (Z(t) <br />'v`= Q(24 hrs) <br />K qD tp <br />"~. <br />K C3tp <br />0 0 <br />0.5 1.75 <br />1.0 6.50 <br />1.5 14.50 <br />2.0 28.00 <br />• 9~ <br />9(t) = qP t <br />t <br />P <br />t =Time of concentration <br />where: tP = Lod time in hours <br />L =Hydraulic length of.flow (ft.) <br />5 = (1000/CN)-10 <br />CN = Cucve number <br />Y = Slope of watershed in <br />for P(t)G0.25 <br />Cat <br />1-t/tp P <br />e <br />_ ~ Ui r. i+l ri = 0 i> m <br />i=1 ~ <br />U1=0 inn <br />t =Time to peak in f,rs <br />DP = Time increment in hrs <br />q =Peak flow rate in cfs <br />AP = watershed area in sq. miles <br />Q(t) = Cum runoff at time t in inches <br />P(t) = Cum rainfall at time t in inches <br />DR = Desi};n rainfall in inches <br />Z(t) = Coordinate for t ype II storm <br />~= Total runoff volume <br />K = Index to get C3t <br /> P <br />q(t) = Unit hydrograph inE1o*a @ time <br /> t in inches <br />e = Base of natural losarithms <br />q = Actual inflow at time = jD <br />j in in Cll L•S' <br />Ui = Ordinate of unit hydrograph at <br /> time i <br />r. = Incr. runoff For incr. i <br />i <br />n+l =Number of unit h yd. ordinates <br />U = 0 <br />0 <br />U = U <br />n <br />m = Number of blocks of runoff <br />~. <br />