Catchment Factor Given Run-off In Inches By Lacey's Formula Calculator

Lacey's Formula:

\[ S = \frac{-120 \times Fm \times RLI}{RLI \times RPI - RPI \times RPI} \]

Monsoon Duration Factor (Fm):

unitless

Runoff Depth In Inches (RLI):

inches

Rainfall Depth In Inches (RPI):

inches

Catchment Factor (S):

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1. What is Lacey's Formula For Catchment Factor?

Lacey's Formula is used to calculate the catchment factor, which refers to topography, shape, size, soil type, and land use (paved or roofed areas). It provides a comprehensive assessment of catchment characteristics for hydrological calculations.

2. How Does the Calculator Work?

The calculator uses Lacey's Formula:

\[ S = \frac{-120 \times Fm \times RLI}{RLI \times RPI - RPI \times RPI} \]

Where:

\( S \) — Catchment Factor (unitless)
\( Fm \) — Monsoon Duration Factor (unitless)
\( RLI \) — Runoff Depth In Inches (inches)
\( RPI \) — Rainfall Depth In Inches (inches)

Explanation: The formula accounts for the relationship between monsoon duration, runoff depth, and rainfall depth to determine the catchment characteristics.

3. Importance of Catchment Factor Calculation

Details: Accurate catchment factor calculation is crucial for hydrological modeling, flood prediction, water resource management, and infrastructure design in catchment areas.

4. Using the Calculator

Tips: Enter Monsoon Duration Factor (unitless), Runoff Depth In Inches, and Rainfall Depth In Inches. All values must be valid positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the significance of the negative sign in the formula?
A: The negative sign indicates the inverse relationship between certain parameters in the catchment factor calculation.

Q2: How is Monsoon Duration Factor determined?
A: Monsoon Duration Factor refers to the period during which monsoon rains occur in a specific region and depends on local monsoon patterns.

Q3: What are typical values for Catchment Factor?
A: Catchment Factor values vary widely depending on topography, soil type, and land use characteristics of the specific catchment area.

Q4: When should this formula be used?
A: This formula is particularly useful for hydrological calculations in regions with significant monsoon rainfall patterns.

Q5: Are there limitations to this formula?
A: The formula may be less accurate in regions with non-monsoonal rainfall patterns or in catchments with extreme topographic variations.