1. What is Depression Head Calculation?

The Depression Head calculation determines the water level depression in a well at a specific time after pumping has stopped. It's an important parameter in hydrogeology for understanding aquifer recovery and well performance characteristics.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( h2 \) — Depression head at time T after pumping stopped (Meter)
• \( h1 \) — Depression head when pumping stopped (Meter)
• \( KA \) — Specific capacity of the well (Meter per Hour)
• \( t \) — Time after pumping stopped (Hour)
• \( 2.303 \) — Conversion factor from natural log to base 10 log

Explanation: This formula calculates how the depression head decreases over time as the well recovers after pumping cessation, using logarithmic decay based on the specific capacity.

3. Importance of Depression Head Calculation

Details: Accurate depression head calculation is crucial for assessing well recovery rates, determining aquifer properties, and planning sustainable groundwater extraction strategies.

4. Using the Calculator

Tips: Enter the initial depression head (h1) in meters, specific capacity (KA) in meters per hour, and time (t) in hours. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is specific capacity (KA)?
A: Specific capacity represents the well's yield per unit drawdown, calculated as discharge rate divided by drawdown during pumping.

Q2: Why use base 10 in this calculation?
A: Base 10 logarithms are commonly used in hydrogeological calculations as they provide convenient scaling for the exponential recovery process.

Q3: What factors affect depression head recovery?
A: Recovery rate depends on aquifer transmissivity, storage coefficient, well construction, and boundary conditions.

Q4: How accurate is this calculation method?
A: This method provides a good approximation for homogeneous aquifers with radial flow to the well, but may need adjustment for complex geological conditions.

Q5: When should field measurements be taken?
A: Field measurements should be taken during pumping tests and recovery tests to validate the calculated values and ensure accurate aquifer characterization.