[Construction and application of a coupled slope surface-subsurface flow model for forested watershed]

Area of Science:

• Hydrology
• Geotechnical Engineering
• Environmental Science

Background:

• Understanding slope surface-subsurface flow is crucial for predicting runoff and erosion.
• Existing models may not fully capture the complex interactions between surface and subsurface water flow on slopes.
• Accurate modeling is essential for effective watershed management and hazard assessment.

Purpose of the Study:

• To develop and validate a coupled model for simulating slope surface-subsurface flow.
• To assess the model's accuracy against experimental data under varying conditions.
• To provide a reliable tool for further research into subsurface flow mechanisms.

Main Methods:

• Constructed a coupled slope surface-subsurface flow model using saturated infiltration theory, the Saint-Venant equation, and Richards equation.
• Solved the model using the finite difference method.
• Conducted laboratory experiments on slope runoff generation with varying slope grades and rainfall intensities.

Main Results:

• The model's simulated surface-subsurface flow processes closely matched observed experimental data.
• Relative errors for peak time, flow duration, peak flow, and gross flow were predominantly below 10%.
• The model demonstrated high precision and practicality in replicating hydrological processes.

Conclusions:

• The developed coupled model is a precise and practicable tool for simulating slope surface-subsurface flow.
• The model's accuracy provides a strong foundation for further investigations into subsurface flow dynamics.
• This research offers a theoretical basis for enhancing existing rainfall-runoff watershed models.