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(25%) Route the following inflow hydrograph using the storage indication method:
| Time (hr) | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
| Inflow (m3/s) | 10 | 20 | 50 | 80 | 90 | 100 | 90 | 60 | 50 | 40 | 30 | 20 | 10 |
Assume baseflow is 10 m3/s, K = 4 hr, Δt = 1 hr.
Show tabular computations.
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(25%) Given the following inflow hydrograph to a certain
stream channel reach, calculate the outflow by the Muskingum method.
| Time (hr) | 0 | 3 | 6 | 9 | 12 | 15 | 18 | 21 | 24 | 27 | 30 | 33 | 36 |
| Inflow (m3/s) | 100 | 120 | 150 | 200 | 250 | 275 | 250 | 210 | 180 | 150 | 120 | 110 | 100 |
Assume baseflow is 100 m3/s, K = 2.4 hr, X = 0.1, and Δt = 3 hr. Show tabular computations.
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(25%) Use the Clark method to derive a 1-hr unit hydrograph
for a catchment with the following time-area diagram:
|
Time (hr) | 0-1 | 1-2 |
2-3 | 3-4 | 4-5 | 5-6 | |
Area (km2) | 12 | 20 |
42 | 66 | 30 | 16 |
Use K = 2 hr, and Δt = 1 hr. Show tabular computations.
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(25%) Please answer each question in one clear-and-concise paragraph:
- In reservoir routing, when the inflow and the outflow coincide, the outflow is a maximum. Explain why.
- In reservoir routing, there is no apparent lag between the start of inflow and the start of outflow. Explain why.
- Why does the time-area method overestimate the flood peak?
- What is the difference between Muskingum and Muskingum-Cunge methods of flood routing?
- Why is a purely
physically based infiltration formula likely to be limited in a real world situation?
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