5. (a) With respect to hydrograph routing, explain the underlying difference between “river routing” and “level pool rou
Posted: Sat May 21, 2022 1:15 pm
- 5 A With Respect To Hydrograph Routing Explain The Underlying Difference Between River Routing And Level Pool Rou 1 (127.14 KiB) Viewed 17 times
difference between “river routing” and “level pool routing”. [3
Marks]
(b) A dam is to be constructed to form a new reservoir. The dam
spillway is 35m in length and has a crest elevation of 57.4 m. The
spillway outflow (O) can be calculated from: O = 1.7Lh1.5, where O
is in m3 /s, L is the spillway length (m) and h is depth of water
above spillway crest (m).
Table 1 shows the routing curve data for the reservoir. TableQ5-
1 Monthly flow volumes
(i) Construct the reservoir routing curves. [4 Marks] (ii)
Assuming that the reservoir is initially full, route the inflow
hydrograph shown in Table 2 through the reservoir until time = 10
hours. [12 Marks]
TableQ5- 2 Monthly flow volumes The following equation may be
useful
(iii) What is maximum head of water over the spillway and the
maximum expected water surface elevation? [4 marks]
(iv) Determine the values of translation and attenuation. [2
marks]
5. (a) With respect to hydrograph routing, explain the underlying difference between “river routing” and “level pool routing”. [3 Marks) (b) A dam is to be constructed to form a new reservoir. The dam spillway is 35m in length and has a crest elevation of 57.4 m. The spillway outflow (O) can be calculated from: 0= 1.7Lh!.5, where is in m/s, L is the spillway length (m) and h is depth of water above spillway crest (m). Table 1 shows the routing curve data for the reservoir. TableQ5- 1 Monthly flow volumes Outflow 0 5 15 28 43 60 99 120 (mºs) 25 0 139284433588 751923 1104 1292 + ΔΙ. (m/s) 78 (1) Construct the reservoir routing curves. [4 Marks) (ii) Assuming that the reservoir is initially full, route the inflow hydrograph shown in Table 2 through the reservoir until time = 10 hours. [12 Marks) TableQ5- 2 Monthly flow volumes Time (hr) 0 1 2 3 4 5 7 8 11 Flow 08 34 116 200 195 168 114 61 27 8 0 (m/s) 6 9 10 +[ The following equation may be useful 25 2s, [1 +12]+ 0, +02 Δf At (iii) What is maximum head of water over the spillway and the maximum expected water surface elevation? [4 marks) (iv) Determine the values of translation and attenuation. [2 marks] [25 MARKS]