An analytical model for simulating the rainfall-interception-infiltration-runoff process with non-uniform rainfall.

ABSTRACT

The rainfall runoff process is a critical factor in determining the transport of surface materials. Simulating the surface runoff process is fundamental to accurately characterize soil erosion and soil nutrient loss. This research aims to develop a comprehensive simulation model for rainfall-interception-infiltration-runoff under vegetation cover conditions. The model integrates three key components a vegetation interception model, Philip's infiltration model, and a kinematic wave model. By combining these models, an analytical solution is derived to simulate slope runoff considering vegetation interception and infiltration during non-constant rainfall events. To validate the reliability of the analytical solution, a numerical solution was obtained using the Pressimann Box scheme method and compared with the analytical results. The comparison confirms the accuracy and robustness of the analytical solution (R2 = 0.984, RMSE = 0.0049 cm/min, NS = 0.969). Moreover, this study investigates the influence of two significant parameters, Intm and k, on the production flow process. The analysis reveals that both parameters exert a significant impact on the timing of production initiation and the magnitude of runoff. Specifically, Intm exhibits a positive correlation with runoff intensity, while k displays a negative correlation. This research introduces a novel simulation method that enhances our understanding and modeling of rainfall production and convergence under complex slope conditions. The proposed model provides valuable insights into rainfall-runoff dynamics, particularly in scenarios characterized by varying rainfall patterns and vegetation cover. Overall, this study contributes to advancing the field of hydrological modeling and offers a practical approach for quantifying soil erosion and nutrient loss under different environmental conditions.