1. What is Regional Constant?

The Regional Constant (Cr) represents watershed slope and storage effects in hydrological calculations. It is a dimensionless parameter used to characterize the relationship between basin lag time and watershed characteristics.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Cr \) — Regional Constant (dimensionless)
• \( tp \) — Basin Lag (hours)
• \( Lb \) — Length of Basin (meters)
• \( Lca \) — Distance along Main Water Course (meters)

Explanation: The formula calculates the regional constant by dividing the basin lag time by the product of basin length and distance along the main water course raised to the power of 0.3.

3. Importance of Regional Constant Calculation

Details: Accurate calculation of the regional constant is crucial for hydrological modeling, flood prediction, and watershed management. It helps in understanding the storage and slope characteristics of watersheds.

4. Using the Calculator

Tips: Enter basin lag in hours, length of basin in meters, and distance along main water course in meters. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical range of Regional Constant values?
A: Regional Constant values typically range from 0.1 to 0.3, depending on watershed characteristics.

Q2: How does basin length affect the Regional Constant?
A: Longer basins generally result in smaller Regional Constant values due to increased travel time and storage effects.

Q3: What factors influence the basin lag time?
A: Basin lag time is influenced by watershed slope, soil type, vegetation cover, and antecedent moisture conditions.

Q4: Can this formula be used for all types of watersheds?
A: While generally applicable, the formula may need calibration for specific regional characteristics and watershed types.

Q5: What are the limitations of this calculation?
A: The calculation assumes uniform watershed characteristics and may not account for extreme weather events or complex topography.