GATE 2023 CE (CE1) – Question 33
A canal supplies water to an area growing wheat over 100 hectares. The duration between the first and last watering is 120 days, and the total depth of water required by the crop is 35 cm. The most intense watering is required over a period of 30 days and requires a total depth of water equal to 12 cm. Assuming precipitation to be negligible and neglecting all losses, the minimum discharge (in m$^3$/s, rounded off to three decimal places) in the canal to satisfy the crop requirement is __________________.
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Correct answer: 0.036 to 0.056
Explanation
The canal must meet the peak demand, which is the most intense watering: 12 cm in 30 days over $100$ ha $= 10^6$ m². The volume is $10^6 \times 0.12 = 1.2 \times 10^5$ m³ in $30 \times 86400 = 2.592 \times 10^6$ s. The discharge is $\frac{1.2 \times 10^5}{2.592 \times 10^6} = 0.0463$ m³/s.