Flood Discharge By Nawab Jang Bahadur Formula Calculator

Nawab Jang Bahadur's Formula:

\[ Q_N = C_N \times (A_{km})^{0.993 - \frac{1}{14} \times \log_{10}(A_{km})} \]

Flood Discharge (Q_N):

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1. What is Nawab Jang Bahadur's Formula?

Nawab Jang Bahadur's Formula is an empirical equation used in hydrology to estimate peak flood discharge from a catchment area. It's particularly relevant for flood estimation in certain regions of India and accounts for the logarithmic relationship between catchment area and flood discharge.

2. How Does the Calculator Work?

The calculator uses Nawab Jang Bahadur's formula:

\[ Q_N = C_N \times (A_{km})^{0.993 - \frac{1}{14} \times \log_{10}(A_{km})} \]

Where:

\( Q_N \) — Flood discharge (m³/s)
\( C_N \) — Nawab Jang Bahadur constant (empirical coefficient)
\( A_{km} \) — Catchment area (km²)
\( \log_{10} \) — Base-10 logarithm function

Explanation: The formula calculates flood discharge based on catchment area with an exponent that varies logarithmically with the area size, providing a more accurate estimation for different catchment sizes.

3. Importance of Flood Discharge Calculation

Details: Accurate flood discharge estimation is crucial for designing hydraulic structures, flood control measures, urban drainage systems, and for flood risk assessment and management in watershed areas.

4. Using the Calculator

Tips: Enter the Nawab Jang Bahadur constant (specific to your region) and the catchment area in square kilometers. Both values must be positive numbers for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical range for Nawab Jang Bahadur constant?
A: The constant varies by region and should be determined based on local hydrological studies. Typical values range from 10 to 100 for different geographical areas.

Q2: How accurate is this formula compared to other methods?
A: The accuracy depends on the region and available data. It's generally considered reliable for preliminary flood estimation in areas where it has been calibrated.

Q3: What catchment area sizes is this formula suitable for?
A: The formula is designed for medium to large catchment areas, typically ranging from hundreds to thousands of square kilometers.

Q4: Are there limitations to this formula?
A: Like all empirical formulas, it may not account for all hydrological factors and should be used with caution. Local calibration and validation are recommended.

Q5: Can this formula be used for urban drainage design?
A: This formula is primarily designed for natural catchment areas. For urban drainage, other methods considering impervious surfaces and drainage infrastructure may be more appropriate.