MULTILEVEL MODEL FOR FLOOD WAVE-PROPAGATION IN FLOOD-AFFECTED AREAS

A hyperbolic model for the simulation of flood wave propagation on ini tially dry land is presented. The convective inertia terms are neglect ed in the momentum equations. This assumption allows the use of a fini te element scheme with linear shape functions for the free surface ele vations and constant unit discharges inside each element. An appropria te use of the explicit and implicit approximation of the spatial deriv atives is able to avoid the introduction of internal boundaries in the case of vertical discontinuities of the terrain elevation. This is ob tained without losing the desirable features of the system matrix or l imiting the maximum Courant number. The efficiency and the reliability of the proposed method are investigated for a flood in the south of S icily, Italy, where a detailed description of the ground morphology ha s been proved to be essential for obtaining a good match between measu red and computed maximum water depths.