SIMULATION OF OVERLAND FLOW DUE TO RAINFALL USING SMOOTHED PARTICLE HYDRODYNAMICS

Abstract

 The 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 method. The terrain and objects on it such as buildings and other strictures 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 contens used to set the infiltration conditions. The basic method is verified with the experimental data of rainfall runoff from a model plot and comparing with existing runoff models based on two-dimensional shallow water approximation. Then it is applied to a simulation of rainfall runoff over a real catchment in Malaysia.