Abstract
Many recent numerical models for predicting flood inundation flows are based on the system of shallow water equations. Though the shallow water equations are highly precise to describing the motion of inundation flows in the flood inundated area where the water is continuous, it is not appropriate to be applied at the frontal area of the inundation flows, because the water is not only discontinuous, but the neighboring dry bed is also beyond the describable range of shallow water equations. Present research gave a focus to the front of flood inundation flows. The impacts to the gradient of water depth at flow front due to different mesh size, the effects of critical depth for water motion, and the contribution of the velocity conditions, etc, were investigated here with one dimensional, axisymmetrical and two dimensional dam breaking problems for an incompressible ideal fluid on a horizontal bed.
