Time At Which Drawdown Is Caused By Real Well At Observation Well Calculator

Formula Used:

\[ t_r = \frac{r_r^2 \times t_i}{r_i^2} \]

Distance from Observation Well to Real Well:

Time of Drawdown caused by Image Well:

Distance from Observation Well to Image Well:

Time of Drawdown caused by Real Well:

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1. What is the Time of Drawdown Formula?

The formula calculates the time at which drawdown is caused by a real well at an observation well based on the relationship between real and image wells in aquifer analysis. This is particularly important in boundary analysis for aquifer testing.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ t_r = \frac{r_r^2 \times t_i}{r_i^2} \]

Where:

\( t_r \) — Time of Drawdown caused by Real Well (s)
\( r_r \) — Distance from Observation Well to Real Well (m)
\( t_i \) — Time of Drawdown caused by Image Well (s)
\( r_i \) — Distance from Observation Well to Image Well (m)

Explanation: The formula establishes a proportional relationship between time and the square of distances, based on the principle of hydraulic similarity between real and image wells.

3. Importance of Time Calculation

Details: Accurate time calculation is crucial for understanding aquifer behavior, determining boundary effects, and predicting drawdown patterns in groundwater systems.

4. Using the Calculator

Tips: Enter all distances in meters and time values in seconds. All values must be positive and non-zero for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What is an image well in aquifer analysis?
A: An image well is a theoretical well used to simulate the effect of hydraulic boundaries in aquifer systems.

Q2: Why is the relationship squared in the formula?
A: The squared relationship comes from the radial flow equations in groundwater hydrology, where time is proportional to the square of distance.

Q3: When is this formula typically used?
A: This formula is used in aquifer boundary analysis, particularly when dealing with impermeable or recharge boundaries.

Q4: What are the limitations of this approach?
A: This approach assumes ideal aquifer conditions and may not account for complex geological formations or heterogeneous aquifer properties.

Q5: How accurate are the results from this calculation?
A: The accuracy depends on the precision of input measurements and how well the actual aquifer conditions match the theoretical assumptions.