Rainfall Intensity For Phi Index Of Practical Use Calculator

Rainfall Intensity Formula:

\[ I = (\phi \times 24) + R_{24-h} \]

Intensity of Rainfall:

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1. What is the Rainfall Intensity Formula?

The Rainfall Intensity formula calculates the intensity of rainfall based on the Φ-Index and 24-hour runoff. It provides a practical approach to determine rainfall intensity for hydrological analysis and water resource management.

2. How Does the Calculator Work?

The calculator uses the Rainfall Intensity formula:

\[ I = (\phi \times 24) + R_{24-h} \]

Where:

\( I \) — Intensity of Rainfall (cm/hr)
\( \phi \) — Φ-Index of the catchment (cm/hr)
\( R_{24-h} \) — Runoff in Cm from 24h Rainfall (cm)

Explanation: The formula combines the constant infiltration capacity (Φ-Index) and the total runoff over 24 hours to determine the rainfall intensity.

3. Importance of Rainfall Intensity Calculation

Details: Accurate rainfall intensity calculation is crucial for flood forecasting, drainage system design, irrigation planning, and hydrological modeling in water resource management.

4. Using the Calculator

Tips: Enter Φ-Index in cm/hr and 24-hour runoff in cm. Both values must be non-negative numbers for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What is Φ-Index in hydrology?
A: Φ-Index represents the constant infiltration capacity of a catchment that would produce the actual total runoff for a given rainfall amount.

Q2: How is 24-hour runoff measured?
A: 24-hour runoff is typically measured using runoff gauges or calculated from rainfall and infiltration data over a 24-hour period.

Q3: What are typical values for rainfall intensity?
A: Rainfall intensity varies widely from light rain (0.25 cm/hr) to heavy downpours (2.5+ cm/hr), depending on climatic conditions and storm characteristics.

Q4: When is this formula most applicable?
A: This formula is particularly useful for practical hydrological applications where Φ-Index and 24-hour runoff data are available for intensity calculation.

Q5: Are there limitations to this equation?
A: The formula assumes constant infiltration capacity and may be less accurate for extreme weather events or in areas with highly variable soil conditions.