Author(s): Akihiko Nakayama; Xin Yan Lye
Linked Author(s): Akihiko Nakayama
Keywords: Rainfall-runoff simulation smoothed particle hydrodynamics inundation
Abstract: The three-dimensional (3-D) Weakly Compressible Smoothed Particle Hydrodynamics (WCSPH) has been reformulated to simulate overland flow on natural terrain due to rainfalls. The rainfall is lumped into discrete particles falling over the terrain and the overland flow is simulated as three-dimensional free surface flows over topography following the WCSPH framework. The terrain and objects on it such as buildings and other structures are represented by boundary particles that are distributed over the combined surfaces having the normal directions and the roughness height used for setting the dynamic boundary conditions and the actual and the potential moisture contents used to set the infiltration conditions. The basic method is verified with experimental results of rainfall runoff from laboratory model plots and compared with existing runoff models. Then it is applied to a simulation of rainfall runoff over real terrains in Malaysia. It is found that the simulation by the present method gives details of the overland flows that would not been obtained by the existing two-dimensional methods.
Year: 2025