Peak Rate of Runoff from Burkli-Ziegler Formula Calculator

Burkli-Ziegler Formula:

\[ Q_{BZ} = \frac{K' \times I_{BZ} \times A_D}{455} \times \sqrt{\frac{S_o}{A_D}} \]

Runoff Coefficient for Burkli Zeigler:

Intensity of Rainfall in Burkli Zeigler:

cm/hr

Drainage Area:

m²

Slope of the ground:

Peak Rate of Runoff for Burkli Zeigler:

m³/s

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1. What is the Burkli-Ziegler Formula?

The Burkli-Ziegler formula is an empirical equation used to estimate the peak rate of runoff from a drainage area during rainfall events. It considers factors such as runoff coefficient, rainfall intensity, drainage area, and ground slope to predict maximum discharge rates.

2. How Does the Calculator Work?

The calculator uses the Burkli-Ziegler formula:

\[ Q_{BZ} = \frac{K' \times I_{BZ} \times A_D}{455} \times \sqrt{\frac{S_o}{A_D}} \]

Where:

\( Q_{BZ} \) — Peak Rate of Runoff for Burkli Zeigler (m³/s)
\( K' \) — Runoff Coefficient for Burkli Zeigler (dimensionless)
\( I_{BZ} \) — Intensity of Rainfall in Burkli Zeigler (cm/hr)
\( A_D \) — Drainage Area (m²)
\( S_o \) — Slope of the ground (dimensionless)

Explanation: The formula calculates peak runoff rate by considering the product of runoff coefficient, rainfall intensity and drainage area, then adjusting for the effect of ground slope relative to drainage area size.

3. Importance of Peak Runoff Rate Calculation

Details: Accurate estimation of peak runoff rates is crucial for designing drainage systems, stormwater management infrastructure, flood control measures, and urban planning to prevent flooding and water damage.

4. Using the Calculator

Tips: Enter the runoff coefficient (typically 0.1-0.9), rainfall intensity in cm/hr, drainage area in square meters, and ground slope (dimensionless ratio). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical range for runoff coefficients?
A: Runoff coefficients typically range from 0.1 for permeable surfaces to 0.9 for impervious surfaces like concrete or asphalt.

Q2: How is rainfall intensity determined?
A: Rainfall intensity is usually obtained from local rainfall data, intensity-duration-frequency curves, or meteorological records for specific return periods.

Q3: What are the limitations of the Burkli-Ziegler formula?
A: The formula is empirical and may not account for all hydrological factors. It works best for small to medium drainage areas and may require calibration for local conditions.

Q4: How is ground slope measured?
A: Ground slope is typically expressed as a ratio (vertical rise/horizontal run) or percentage. In this formula, it's used as a dimensionless value.

Q5: When should this formula be used?
A: The Burkli-Ziegler formula is commonly used in civil engineering for preliminary drainage design, especially in urban and suburban areas with known rainfall characteristics.