SFINCS

SFINCS (Super-Fast INundation of CoastS) solves simplified shallow-water equations tuned for one job: compound flooding, where surge, tide, waves, river flow and rainfall arrive together. By trading full-momentum physics for a carefully validated reduced-complexity scheme (with a subgrid approach that preserves fine topography on coarse grids), it runs orders of magnitude faster than conventional 2D models — fast enough for probabilistic ensembles and forecasting.

It has become the go-to open model for compound coastal flood risk, used in global studies and operational systems alike, and slots into the Deltares ecosystem (HydroMT builds SFINCS models; Delft-FEWS runs them operationally). Open source under GPL-3.