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The Standard Duration of Effective Rainfall is a hydrological parameter used to estimate the time period during which rainfall contributes directly to runoff. It's an important concept in watershed management and flood prediction.
The calculator uses the formula:
Where:
Explanation: This formula calculates the standard duration of effective rainfall based on the time of peak discharge and the time of concentration of the watershed.
Details: Accurate estimation of effective rainfall duration is crucial for hydrological modeling, flood prediction, and designing drainage systems. It helps in understanding how much rainfall actually contributes to runoff and potential flooding.
Tips: Enter Time of Peak and Time of Concentration in hours. Both values must be positive numbers. The calculator will compute the Standard Duration of Effective Rainfall.
Q1: What is Time of Peak?
A: Time of Peak is the time interval from the start of rainfall to the peak discharge in a watershed.
Q2: What is Time of Concentration?
A: Time of Concentration is the time required for water to travel from the most remote point in a watershed to the outlet.
Q3: Why is 0.6 used as a coefficient in the formula?
A: The coefficient 0.6 is an empirical factor derived from hydrological studies that accounts for the relationship between time of concentration and the effective rainfall duration.
Q4: What are typical values for these parameters?
A: Values vary significantly based on watershed characteristics. Time of Concentration can range from minutes for small urban areas to hours for large rural watersheds.
Q5: Can this formula be used for all types of watersheds?
A: While widely applicable, the formula may need adjustments for extremely large or small watersheds, or for areas with unusual hydrological characteristics.