Direction: The drainage area of a watershed is 50 km². The φ index is 0.5 cm/hour and the base flow at the outlet is 10 m³/s. One hour unit hydrograph (unit depth = 1 cm) of the watershed is triangular in shape with a time base of 15 hours. The peak ordinate occurs at 5 hours.
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The peak ordinate (in m³/s/cm) of the unit hydrograph is
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- 10.00
- 18.52
- 37.03
- 185.20
Correct Option: B
Volume of water = Area under curve
| = | × 15 × Q0 × 3600 | |
| 2 |
Area × Depth = Volume
Depth = 1 cm (UH)
| (50 × 106) × (1 × 10–2) = | × 15 × 3600 × Q0 | |
| 2 |
∴ Q0 = 18.52 m³/s.
