Hydraulic Gradient Calculator
Calculate hydraulic gradient to determine groundwater flow direction and magnitude
Calculate Hydraulic Gradient
Total hydraulic head at the first measurement point
Total hydraulic head at the second measurement point
Horizontal distance between the two measurement points
Hydraulic Gradient Results
Flow Direction: No Flow
No hydraulic gradient exists - water is in equilibrium
Formula: i = (h₁ - h₂) / L = 0.000 / 0.000 = 0.0000
Distance used: 0.000 m
Formula Used
i = (h₁ - h₂) / L
i: Hydraulic gradient (dimensionless)
h₁: Hydraulic head at point 1 (0 m)
h₂: Hydraulic head at point 2 (0 m)
L: Distance between points (0.000 m)
Example Calculation
Groundwater Flow Example
Scenario: Two monitoring wells along a flow path
Well 1 hydraulic head: 25.4 m
Well 2 hydraulic head: 23.1 m
Distance between wells: 150 m
Calculation Steps
Step 1: Calculate head difference: Δh = 25.4 - 23.1 = 2.3 m
Step 2: Apply formula: i = Δh / L = 2.3 / 150 = 0.0153
Step 3: Interpret result: Positive gradient → flow from well 1 to well 2
Result: Hydraulic gradient = 0.0153 (1.53%)
Gradient Interpretation
Positive Gradient
i > 0
Flow from point 1 to point 2
Zero Gradient
i = 0
No flow, equilibrium state
Negative Gradient
i < 0
Flow from point 2 to point 1
Typical Gradient Values
Flat terrain: 0.001 - 0.01
Very gentle slopes
Rolling hills: 0.01 - 0.1
Moderate topography
Steep terrain: 0.1 - 1.0
Mountainous areas
Near wells: Variable
Locally altered gradients
Understanding Hydraulic Gradient
What is Hydraulic Gradient?
Hydraulic gradient is the driving force for groundwater flow. It represents the change in hydraulic head per unit distance and determines both the direction and rate of groundwater movement.
Components of Hydraulic Head
- •Elevation head: Height above datum
- •Pressure head: Water pressure at point
- •Velocity head: Usually negligible in groundwater
Applications
- •Groundwater flow direction mapping
- •Contaminant plume tracking
- •Well field design and optimization
- •Environmental impact assessment
- •Groundwater modeling and simulation
Important: Hydraulic gradient is a vector quantity - both magnitude and direction are important for understanding groundwater flow patterns.