1. What is the Green-Ampt Infiltration Model?

The Green-Ampt infiltration model is a physically-based method for estimating infiltration rates in soils. It provides a mathematical representation of water movement into unsaturated soils and is widely used in hydrology and soil science for predicting infiltration capacity.

2. How Does the Calculator Work?

The calculator uses the Green-Ampt infiltration model formula:

Where:

• \( f_p \) — Infiltration Capacity at Any Time t (cm/hr)
• \( m \) — Parameter 'm' of Infiltration Model by Green-Ampt (cm/hr)
• \( n \) — Parameter 'n' of Infiltration Model by Green-Ampt (cm/hr)
• \( F_p \) — Cumulative Infiltration Capacity (cm/hr)

Explanation: The equation calculates the instantaneous infiltration capacity based on the Green-Ampt parameters and cumulative infiltration. The model assumes a sharp wetting front and uniform soil properties.

3. Importance of Infiltration Capacity Calculation

Details: Accurate infiltration capacity estimation is crucial for hydrological modeling, flood prediction, irrigation planning, and understanding soil-water relationships in agricultural and environmental applications.

4. Using the Calculator

Tips: Enter parameter 'm' and 'n' values in cm/hr, and cumulative infiltration capacity in cm/hr. All values must be positive numbers with cumulative infiltration capacity greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: What do parameters 'm' and 'n' represent in the Green-Ampt model?
A: Parameter 'm' represents the minimum infiltration capacity, while parameter 'n' is related to the soil's hydraulic conductivity and suction head at the wetting front.

Q2: How are Green-Ampt parameters determined for different soils?
A: Parameters are typically determined through laboratory experiments or field measurements and vary based on soil texture, structure, and initial moisture content.

Q3: What are typical ranges for Green-Ampt parameters?
A: Parameter 'm' typically ranges from 0.1-2.0 cm/hr for most soils, while parameter 'n' can range from 1-20 cm/hr depending on soil type and conditions.

Q4: What are the limitations of the Green-Ampt model?
A: The model assumes homogeneous soil properties, constant rainfall intensity, and may not accurately represent infiltration in layered soils or under variable rainfall conditions.

Q5: How does cumulative infiltration affect infiltration capacity?
A: As cumulative infiltration increases, infiltration capacity decreases due to the reduction in available storage capacity and the movement of the wetting front deeper into the soil profile.