Integrated Rainfall-Runoff Process with Shallow Water Model by Smoothed Particle Hydrodynamics: Infiltration Effect Implementation

The rainfall-runoff is an important hydrological process, which relates to the outfall flow response of a catchment to a given amount of rainfall. Prediction and analysis of catchment flow becomes important to drainage network design and operation in engineering practice. Rainfall-runoff modeling can be classified into two major categories based on the hydrologic system: black box lumped modeling and physically based distributed modeling. For distributed modeling, it considers variations in variables and parameters based on understanding different physical processes. Different numerical methods are available for distributed modeling, in which the solution for the shallow water equations using smoothed particle hydrodynamics (SPH) is attractive, being a mesh-free, automatically adaptive method without special treatment for wet-dry interfaces.
This paper aims to innovatively integrate the infiltration model into the shallow water equations (SWEs) system with SPH method, thereby representing a more complete rainfall-runoff process through the extended infiltration effect. Mass-varied particles SPH method is adopted to solve developed model. The obtained numerical results are validated through the experimental data available in the literature as well as experimental tests conducted in this study. The achievements and findings of this study are expected to improve and extend the current models of the hydrological process.