Integrated rainfall-runoff process with shallow water model by mass varied smoothed particle hydrodynamics: Infiltration effect implementation

Rainfall-runoff modeling is essential for addressing a wide range of issues in urban drainage system design and operation in both scientific research and engineering practice. Recently, it has become increasingly attractive to use the smoothed particle hydrodynamics (SPH) method to model rainfall-runoff because of its inherent features such as mesh-free and automatic adaptiveness for wet-dry interfaces. However, one of its inadequacies is the lack of an infiltration effect within rainfall-runoff modeling. Hence, we propose a new methodology that innovatively integrates the infiltration effect into the shallow water equation (SWE) system with the SPH method (SPH-SWE) to represent a more complete rainfall-runoff process. In the proposed method, the mass-varied SPH-SWE (MVSPH-SWE) method is enhanced by integrating the infiltration model. A naked area treatment (NAT) method is subsequently proposed to improve the modeling efficiency and accuracy. The obtained numerical results are validated using experimental data from the literature. The results demonstrate that the proposed method is accurate and reliable. The achievements and findings of this study are expected to improve and extend the use of existing hydrological process models.