Validation of NSWING, a multi-core finite difference code for tsunami propagation and run-up

We present the finite difference tsunami code NSWING (Non-linear Shallow Water model With Nested Grids), that solves the non-linear shallow water equations using the discretization and explicit leap-frog finite difference scheme, in a Cartesian or Spherical frame, as developed by Liu et al. (1998). An open boundary condition is used on the outward limit of the grid, whenever it does not correspond to land. The model also incorporates Coriolis acceleration, bottom friction and a moving boundary scheme to model run-up. Multiple levels of nesting are possible. NSWING runs on MS windows operating system using more than one core. The code is applied to classical benchmark tests (Synolakis et al., 2007) and to a test case in SW Portugal. It is shown that the code reproduces well the numerical benchmarks, improves its accuracy with increasing resolution and ensures mass conservation. It is also shown that NSWING can efficiently provide inundation modelling for high resolution studies. This work is a contribution to GEONUM project FCT-ANR/MAT-NAN/0122/2012