1. What is the Time Calculation Formula?

The formula calculates time based on the ratio of two depression heads using natural logarithm. It's commonly used in hydrogeology and well pumping calculations for coarse sand aquifers.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( t \) — Time in hours
• \( h1 \) — Depression Head 1 in meters
• \( h2 \) — Depression Head 2 in meters
• \( e \) — Napier's constant (2.718281828459045)
• \( \log \) — Logarithmic function

Explanation: The formula calculates the time required based on the logarithmic relationship between the two depression head measurements.

3. Importance of Time Calculation

Details: Accurate time calculation is crucial for determining pumping durations, well recovery rates, and aquifer characteristics in hydrogeological studies.

4. Using the Calculator

Tips: Enter both depression head values in meters. Both values must be positive numbers greater than zero for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What are depression heads in well hydraulics?
A: Depression heads represent the difference between the static water table level and the water level in the well during or after pumping.

Q2: Why use natural logarithm in this calculation?
A: Natural logarithm provides the most accurate mathematical representation of the time-dependent relationship between water level changes in porous media.

Q3: What is the typical range of values for depression heads?
A: Depression heads typically range from 0.1 to 30 meters, depending on aquifer characteristics and pumping conditions.

Q4: Can this formula be used for other soil types?
A: While specifically designed for coarse sand, the formula can provide approximate values for other granular aquifers with similar hydraulic properties.

Q5: How accurate is this time calculation method?
A: The method provides good accuracy for homogeneous coarse sand aquifers under ideal conditions, though field measurements may require adjustments for real-world complexities.