Drainage of one ha-cm in 24 hours equals to drainage of how much water
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Keep this standard conversion factor in mind:
\[ 1 \text{ ha-cm/day} \approx 157 \text{ lps} \]
You can multiply this constant by any given volume (e.g., draining \( 5 \text{ ha-cm/day} = 5 \times 157 \approx 79 \text{ lps} \)) to quickly solve drainage design problems.
Step 1: Understanding the Concept:
In agricultural engineering and hydrology, the volume of drainage water is often expressed in depth-area units, such as hectare-centimeters (\( \text{ha-cm} \)).
To design drainage channels or pumps, this volumetric unit must be converted into a continuous flow rate, typically measured in liters per second (lps). Key Formula or Approach:
Volume of \( 1 \text{ ha-cm} \):
\[ V = \text{Area } (A) \times \text{Depth } (d) \]
Convert time to seconds:
\[ t = 24 \text{ hours} = 24 \times 3600 \text{ seconds} \]
Flow rate (\( q \)) in liters per second:
\[ q = \frac{\text{Volume in Litres}}{\text{Time in Seconds}} \] Step 2: Detailed Explanation:
Let us perform the calculations step-by-step:
Calculate the volume of \( 1 \text{ ha-cm} \):
- \( 1 \text{ hectare} = 10,000 \text{ m}^2 \).
- \( 1 \text{ cm} = 0.01 \text{ m} \).
\[ V = 10,000 \text{ m}^2 \times 0.01 \text{ m} = 100 \text{ m}^3 \]
Convert this volume from cubic meters to liters:
- Since \( 1 \text{ m}^3 = 1000 \text{ litres} \):
\[ V = 100 \text{ m}^3 \times 1000 \text{ litres/m}^3 = 100,000 \text{ litres} \]
Calculate the total time in seconds:
\[ t = 24 \text{ hours} \times 3600 \text{ seconds/hour} = 86,400 \text{ seconds} \]
Calculate the constant drainage flow rate required:
\[ q = \frac{100,000 \text{ litres}}{86,400 \text{ seconds}} \approx 1574 \text{ litres/second (lps)} \]
Therefore, draining one hectare-centimeter of water over a 24-hour period requires a continuous flow rate of approximately \( 157 \text{ lps} \). Step 3: Final Answer:
The equivalent drainage flow rate is 157 lps.
