1. What is Saturated Hydraulic Conductivity?

Saturated hydraulic conductivity (K_s) is a measure of a porous medium's capacity to transmit water when it is fully saturated. It's a fundamental property in hydrogeology and soil science that describes how easily water can move through soil or rock.

2. How Does the Calculator Work?

The calculator uses Darcy's Law equation:

Where:

• \( K_s \) — Saturated hydraulic conductivity (m/s)
• \( Q \) — Flow rate (m³/s)
• \( L \) — Length of the sample (m)
• \( A \) — Cross-sectional area (m²)
• \( \Delta h \) — Head difference (m)

Explanation: The equation relates the flow rate through a porous medium to the hydraulic gradient and the intrinsic permeability of the medium.

3. Importance of K_s Calculation

Details: K_s is crucial for designing drainage systems, predicting groundwater flow, assessing contaminant transport, and modeling water movement in agricultural soils.

4. Using the Calculator

Tips: Enter all values in consistent SI units. Flow rate should be measured under steady-state conditions. Ensure all input values are positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What are typical K_s values for different soils?
A: Clay: 10^-9-10^-6 m/s, Loam: 10^-6-10^-5 m/s, Sand: 10^-5-10^-3 m/s, Gravel: >10^-3 m/s.

Q2: How does temperature affect K_s?
A: K_s increases with temperature due to decreased water viscosity. Standard values are often reported at 20°C.

Q3: What's the difference between K_s and permeability?
A: K_s includes fluid properties (viscosity, density) while intrinsic permeability depends only on the porous medium.

Q4: How is K_s measured in the field?
A: Common methods include constant-head and falling-head permeameter tests, or well pumping tests for larger scales.

Q5: Why might lab and field measurements differ?
A: Lab samples may not represent field-scale heterogeneities, and field measurements can be affected by macropores or preferential flow paths.