Drift Wood Diffusion by Overland Flood Flow

A numerical simulation model has been developed for computing the diffusion of drift wood debouching into horizontally two-dimensional flow field. The calculation is accomplished by an interacting combination of Eulerian fluid and Lagragian drift wood equations, in which a turbulent diffusivity and rotational angular velocity of the drift wood are stochas-tically given based on the statistical analysis of these values in the experiments. The positions and rotational angles in a group of drift wood in the experiments are well explained by the calculation.