Implementation of an Implicit Solver in ADCIRC Storm Surge Model

The current state of science does not offer any remedy to stop a hurricane from occurring. Therefore, accurate storm surge models capable of predicting water velocity and elevation are indispensable. In this paper, the implementation of an implicit solver in the Advanced Circulation (ADCIRC) storm surge model is presented. The implemented implicit solver uses hybrid finite element and finite volume techniques for solving shallow water equations. Objectives of this research include: Enhancing numerical stability, providing an option of using large timesteps, and the usage of a relatively easier mathematical formulation than the existing one in ADCIRC. The storm surge hindcast of Hurricane Katrina that hit Louisiana and Mississippi in 2005 is used as a case study. Stability of the solver, comparison of water elevation and velocity against observed data, impact of timestep sizes, and execution times of solvers are thoroughly investigated in this study. Results of the implemented implicit solver are compared with those of existing lumped explicit and semi-implicit solvers of ADCIRC; the findings appear to be very promising