How to use the freshwater lens depth calculator
Estimate how deep the freshwater and saltwater boundary lies below sea level, from the height of the freshwater table above sea level. Enter freshwater head above sea level in the field above; the depth of freshwater-saltwater interface below sea level, depth are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “Ghyben Herzberg”, “saltwater interface depth”, “freshwater lens coastal aquifer”, “calculate freshwater lens depth”, “find depth of freshwater-saltwater interface below sea level”.
Formula
Variables
- hf — Freshwater head above sea level (m)
Worked example
With freshwater head above sea level = 1 m, the calculator gives depth of freshwater-saltwater interface below sea level ≈ 40 m; depth ≈ 0.04 km.
Frequently asked questions
What is the freshwater lens depth calculator used for?
Estimate how deep the freshwater and saltwater boundary lies below sea level, from the height of the freshwater table above sea level. It helps with questions such as “Ghyben Herzberg”, “saltwater interface depth”, “freshwater lens coastal aquifer”.
What is the formula for the freshwater lens depth calculation?
Depth of freshwater-saltwater interface below sea level (m) = 40 × hf. Depth (km) = [Depth of freshwater-saltwater interface below sea level] / 1000. Here hf is freshwater head above sea level (m).
What inputs do I need for the freshwater lens depth (ghyben-herzberg) calculator?
You need freshwater head above sea level in m. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the freshwater lens depth calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the freshwater lens depth result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.