1. What is Modified Drawdown in Well 1?

Modified Drawdown in Well 1 is a calculated value that adjusts the actual drawdown measurement to account for the effects of aquifer thickness. It provides a more accurate representation of the drawdown behavior in pumping well analysis.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( s1' \) — Modified Drawdown 1 (Meter)
• \( s1 \) — Drawdown in Well 1 (Meter)
• \( Hi \) — Initial Aquifer Thickness (Meter)

Explanation: This formula adjusts the measured drawdown by subtracting a correction factor that accounts for the squared drawdown relative to twice the initial aquifer thickness.

3. Importance of Modified Drawdown Calculation

Details: Calculating modified drawdown is crucial for accurate aquifer characterization, well performance analysis, and proper interpretation of pumping test results in hydrogeological studies.

4. Using the Calculator

Tips: Enter the drawdown measurement in meters and the initial aquifer thickness in meters. Both values must be positive numbers greater than zero for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: Why modify the drawdown measurement?
A: The modification accounts for non-linear effects and provides a more accurate representation of the aquifer's response to pumping.

Q2: When should this modified drawdown be used?
A: It's particularly useful in aquifer analysis where the drawdown is significant relative to the aquifer thickness.

Q3: What are typical values for drawdown and aquifer thickness?
A: Drawdown typically ranges from 0.1 to 10 meters, while aquifer thickness can vary from a few meters to hundreds of meters.

Q4: Are there limitations to this formula?
A: This formula assumes specific aquifer conditions and may not be applicable to all hydrogeological settings.

Q5: How does aquifer thickness affect the modification?
A: Thinner aquifers will have a larger correction factor, making the modification more significant.