Modified Green-Ampt model for infiltration analysis in loess area and its parameter determination and verification

Area of Science:

• Geotechnical Engineering
• Soil Science
• Hydrology

Background:

• Classical Green-Ampt (GA) infiltration model has limitations due to ignoring unsaturated soil layers.
• Accurate soil water infiltration modeling is crucial for geotechnical engineering applications.

Purpose of the Study:

• To establish a modified Green-Ampt (MLGA) infiltration model that fully considers soil water profile variations.
• To verify the MLGA model's accuracy and applicability using measured data.
• To perform sensitivity analysis on critical parameters influencing infiltration.

Main Methods:

• Developed the MLGA model using Darcy's law and the continuity equation.
• Integrated internal relationships between infiltration rate and cumulative infiltration from Philip and GA models.
• Validated the model with existing measured data and performed sensitivity analysis via single-factor disturbance.

Main Results:

• The MLGA model demonstrated high accuracy for water infiltration analysis in loess sites, with an average relative error of 5.54%.
• MLGA model showed significantly lower average error (24.47% of Kostiakov, 80.42% of LGAM).
• Saturated water content was identified as a highly sensitive parameter influencing infiltration depth.

Conclusions:

• The MLGA model is reliable and accurate for analyzing water infiltration in loess soils.
• Ensuring accuracy of saturated water content is critical for precise infiltration depth calculations.
• The study provides theoretical support for understanding loess water infiltration mechanisms.