Radius of Influence given Coefficient of Transmissibility with Base 10 Calculator

Formula Used:

\[ Radius\ of\ Influence = Radius\ of\ well \times 10^{\frac{2.72 \times Coefficient\ of\ Transmissibility \times (Initial\ Aquifer\ Thickness - Depth\ of\ Water)}{Discharge\ of\ Liquid}} \]

Radius of Well:

Coefficient of Transmissibility:

m²/s

Initial Aquifer Thickness:

Depth of Water:

Discharge of Liquid:

m³/s

Radius of Influence:

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1. What is Radius of Influence?

Radius of Influence is measured from the center of the well to the point where the drawdown curve meets the original water table. It represents the area around a pumping well where groundwater levels are affected by the pumping.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ Radius\ of\ Influence = Radius\ of\ well \times 10^{\frac{2.72 \times Coefficient\ of\ Transmissibility \times (Initial\ Aquifer\ Thickness - Depth\ of\ Water)}{Discharge\ of\ Liquid}} \]

Where:

Radius of well — Distance from center of well to its outer boundary (m)
Coefficient of Transmissibility — Rate of flow of water through a vertical strip of the aquifer (m²/s)
Initial Aquifer Thickness — Aquifer thickness at initial stage before pumping (m)
Depth of Water — Depth of water in the well measured above the impermeable layer (m)
Discharge of Liquid — Rate of flow of a liquid (m³/s)

Explanation: This formula calculates the extent of influence a pumping well has on the surrounding groundwater levels based on aquifer properties and pumping rate.

3. Importance of Radius of Influence Calculation

Details: Calculating the radius of influence is crucial for well field design, determining safe pumping rates, assessing interference between wells, and managing groundwater resources effectively.

4. Using the Calculator

Tips: Enter all values in appropriate units. Ensure that initial aquifer thickness is greater than depth of water, and all values are positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What factors affect the radius of influence?
A: The radius of influence is affected by aquifer transmissibility, pumping rate, aquifer thickness, and the difference between initial water level and pumping water level.

Q2: How accurate is this calculation method?
A: This method provides a reasonable estimate but actual field conditions may vary due to aquifer heterogeneity and boundary conditions.

Q3: Can this formula be used for confined and unconfined aquifers?
A: This specific formula is typically used for unconfined aquifers. Different formulas may be needed for confined aquifer conditions.

Q4: What is the significance of the coefficient 2.72 in the formula?
A: The coefficient 2.72 is derived from empirical relationships and conversion factors that relate the various parameters in the equation.

Q5: How does pumping rate affect the radius of influence?
A: Higher pumping rates generally result in larger radii of influence, as more water is being extracted from a larger area of the aquifer.