Flood inundation analysis resulting from Levee-break

A combined, one- and two-dimensional hydrodynamic model for flood wave propagation from a breached levee is studied. The one-dimensional model solves the Saint-Venant equations by the Preissmann method, and the two-dimensional model solves a diffusion wave equation by the integrated finite difference method. The overflow through the broken levee is treated as an internal boundary condition in a channel. The model is applied to an actual levee-break case, which occurred on September 12-13, 1990 on the Han River, Korea. Two-dimensional velocity distributions and inundation maps are presented. The computed results agree with observations in terms of inundated depth, flood arrival time, and flooded area.