Numerous applications in virtual reality and computer animation need tools including efficient algorithms, for modeling and simulation of water overland flow. This paper proposes an algorithm and a model for simulation and visualization of rainwater overland flow. We use the finite difference method associated with a dynamic domain to solve the diffusion equations in order to reduce the computation time. The simulation results show the water propagation in rugged terrains. Moreover, the results indicate that our algorithm is highly efficient because it reduces the computation time. The diffusion model and a numerical method were applied in this work for the simulation of water flooding caused by continuous heavy rain in Nakhon Si Thammarat province, southern Thailand. Results show that the flood plain obtained by the diffusion model is similar to the actual flooding area from the real satellite image. This indicates that the diffusion model has high potential, and can be adopted for predictive use in flood risk assessments, water resources management, and disaster prevention from water flooding.
