1. What is Vertical Hydraulic Gradient?

The vertical hydraulic gradient (i) is a dimensionless measure of the change in hydraulic head (Δh) per unit vertical distance (Δz). It indicates the direction and magnitude of groundwater flow in the vertical direction.

2. How Does the Calculator Work?

The calculator uses the vertical hydraulic gradient equation:

Where:

• \( i \) — Vertical hydraulic gradient (dimensionless)
• \( \Delta h \) — Head change (m)
• \( \Delta z \) — Vertical distance (m)

Explanation: The gradient represents the driving force for groundwater flow. A positive value indicates upward flow, negative indicates downward flow.

3. Importance of Hydraulic Gradient

Details: The vertical hydraulic gradient is crucial for understanding groundwater movement, contaminant transport, and designing remediation systems.

4. Using the Calculator

Tips: Enter head change and vertical distance in meters. Both values must be positive (Δz cannot be zero).

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between vertical and horizontal gradient?
A: Vertical gradient measures head change with depth, while horizontal gradient measures head change across lateral distances.

Q2: What are typical gradient values?
A: In natural systems, gradients typically range from 0.001 to 0.1, but can be higher near pumping wells or recharge areas.

Q3: How is head change measured?
A: Using piezometers or wells at different depths to measure hydraulic head (water level elevation + depth to measurement point).

Q4: When is vertical gradient important?
A: Critical for assessing vertical contaminant migration, designing vertical flow barriers, and evaluating aquifer-aquitard interactions.

Q5: What does a zero gradient mean?
A: Indicates no vertical flow (hydrostatic conditions), though horizontal flow may still occur.