Coupled hydrological-hydrodynamic large-scale simulation

Compound flooding is usually induced by the concurrence of coastal storm surge and heavy precipitation induced river flooding, with the former involving oceanic processes and the latter involving hydrological processes. We present a creek-to-ocean 3D baroclinic model based on SCHISM (Semi-implicit Cross-scale Hydroscience Integrated System Model) that aims to unite traditional hydrologic and oceanic models in a single modeling platform, by taking full advantage of the polymorphism (i.e. a single model grid can seamlessly morph between full 3D, 2DV, 2DH and quasi-1D configurations). Using Hurricane Irene’s impact on the east coast as an example, a seamless 2D-3D model grid is implemented to include the entire US East Coast and Gulf of Mexico with all major estuaries and bays resolved (down to 20 m resolution). The model is forced by flows from National Water Model (NWM) at the landward boundary. We present some preliminary results from the simulation of the storm surge and subsequent river flooding events. Sensitivity tests are also conducted to illustrate the importance of including the baroclinic and other effects in the simulation.