Radial Distance Of Well 2 Given Confined Aquifer Discharge Calculator

Formula Used:

\[ R2 = r1 \times 10^{\frac{2.72 \times KWH \times bp \times (h2 - h1)}{Q0}} \]

Radial Distance at Observation Well 1:

Coefficient of Permeability:

m/s

Aquifer Thickness During Pumping:

Depth of Water 1:

Depth of Water 2:

Discharge at Time t=0:

m³/s

Radial Distance at Well 2:

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1. What is the Radial Distance Calculation?

The radial distance calculation determines the distance from a pumping well to an observation well in a confined aquifer system. This calculation is essential in well hydraulics for analyzing drawdown patterns and aquifer characteristics.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ R2 = r1 \times 10^{\frac{2.72 \times KWH \times bp \times (h2 - h1)}{Q0}} \]

Where:

\( R2 \) — Radial Distance at Well 2 (m)
\( r1 \) — Radial Distance at Observation Well 1 (m)
\( KWH \) — Coefficient of Permeability in Well Hydraulics (m/s)
\( bp \) — Aquifer Thickness During Pumping (m)
\( h1 \) — Depth of Water 1 (m)
\( h2 \) — Depth of Water 2 (m)
\( Q0 \) — Discharge at Time t=0 (m³/s)

Explanation: This formula calculates the radial distance to well 2 based on the hydraulic properties of the aquifer and pumping conditions.

3. Importance of Radial Distance Calculation

Details: Accurate radial distance calculation is crucial for determining the extent of cone of depression, designing well fields, and assessing aquifer response to pumping.

4. Using the Calculator

Tips: Enter all required parameters with appropriate units. Ensure radial distances, permeability coefficient, aquifer thickness, and discharge values are positive. Water depths should be non-negative values.

5. Frequently Asked Questions (FAQ)

Q1: What is the significance of the coefficient 2.72 in the formula?
A: The coefficient 2.72 is derived from the conversion factor between natural logarithms and base-10 logarithms used in the Theis equation derivation.

Q2: When is this formula applicable?
A: This formula applies to confined aquifers with steady-state flow conditions and homogeneous, isotropic aquifer properties.

Q3: What are typical values for coefficient of permeability?
A: Permeability coefficients vary widely: gravel (10⁻¹-10⁻² m/s), sand (10⁻³-10⁻⁵ m/s), silt (10⁻⁶-10⁻⁸ m/s), clay (<10⁻⁹ m/s).

Q4: How does aquifer thickness affect the calculation?
A: Greater aquifer thickness generally results in smaller drawdown and larger radial distances for the same pumping rate.

Q5: What are the limitations of this approach?
A: This method assumes ideal conditions and may not account for aquifer heterogeneity, boundary effects, or transient conditions.