Question

Use the 1-h Unit Hydrograph tabulated below to (a) Predict the total streamflow hydrograph that would be observed as a result of a storm whose effective rainfall is also tabulated below. Assume a constant baseflow of 150 m/s. Time 1-H Unit Hydrograph (m/s) 0.00 40.00 130.00 210.00 150.00 120.00 80.00 40.00 15.00 0.00 Time (h) Effective Precipitation (ERH) (cm/h) 1.0 2.0 0-3 3-6 6-9 b) Route the following hydrograph through a river reach for which K = 12.0 h and x = 0.20 c) To prevent downstream flooding, the maximum flow to be released from the catchment is set at 1260 m3/s.

Answer 1

Solution: ERH, Pn in unikaquivalent depth each compute tha Volume Tima (h) ERHCem Pm Cem) 1.0 3.0 6-3 6.D 3-6 2, 0 6-9 4S 3 hours -duraton Here each 2) 6*0H 45XUH 3 xUH Pzt Total P3x 1- H Tima Ch) unit m/se low Cma UH UH UH DRHA1S0 150 O 2. 120 120 270 130 3 39 0 3 90 540 210 63 0 630 7 80 150 690 240 840 (26 3 60 129D 140 780 &0 7 1260 1500 1650 240 40 8 180 1200 900 1350 120 15 13S0 Soo 43 720 480 945 1425 1S75 240 678 11 lo 6s 918 12 630 540 780 13 360 360 516 180 180 33 o 67.5 5 67-5 217.5 n

b) Rouha kao h 2 0.20 ৫ = hour By Muskingum -kz to.5at kc1-2) 0.8at -12 x0.2) 0.Sx1) 12C1-02)+ Co.Sx1) * -o. 18 8) ko o.SDt kCi-) 0.50t (12 x0.2) + Co.Sx1) 12 C1-0.2)+(0-Sx) O 287 2 -5 2 k C1-2) 2 kCI-R)0. gat 2C-0.26.9 xi) 12 C1-6.2) +(0-Sx ০.१००१ 2 Out lou 0 + C 2 O In kabla 80 thined column O.1881 x row 28.215 -s Fourth column O.287X 270 77.49 1S0 FIFTH Column ০ १००१ ५ 2 135.135 Suxth column -28-215+77. 49 t135-135 2 184-41

CO -0.1881 C1 0.287 C2 0.9009 Total flow CO*li+1 Time C1*li C2*Oi outflow 150 1 150 -28.215 2 270 77.49 135.135 184.41 3 540 -50.787 154.98 166.135 270.328 780101.574 223.86 243.5385 365.8245 4 840146.718 241.08 329.5713 423.9333 5 370.23 381.9215 594.1475 473.55 535.2675 766.1685 387.45 690.2412 767.3262 430.5 691.2841 867.8491 452.025 781.8453951.7203 305.655 857.4048 866.8023 223.86 780.9022 804.4357 146.37 724.7161 724.3681 1290158.004 6 1650 -242.649 1350 -310.365 1500 -253.935 7 9 10 1575 -282.15 1065 296.258 780200.327 510-146.718| 1 12 13 94.71 652.5832 651.3622 14 330 -95.931 62.4225 586.8122 587.1617 15 217.5 -62.073 150-40.9118 528.974 531.1123 16 43.05