A 2D numerical scheme to solve the shallow water equations is presented. The equations
are solved in time by means of a Strang splitting approach. Exploiting the rotational
invariance, the advective part of the problem is evaluated solving at first order a sequence of
augmented 1D Riemann problems. The scheme works on unstructured triangular and
quadrangular elements, also mixed together. Thus the domain can be discretized in the best
possible way, following the main flow direction with quadrangular almost regular cells and
maintaining quite homogeneous grid sizes. The former characteristic allows the scheme to
work more effectively along the main flow direction and the latter helps in reducing
computational time. The model can be easily applied to real environmental problems, with
complex topography. The numerical scheme is applied to 1D and 2D dam break problem with
good results. Different grids are used to check the influence of the domain discretization on
the results.
