A scalable unstructured grid 3-dimensional finite volume model for the shallow water equations

We present an unstructured grid finite volume three-dimensional hydrostatic model. An important aspect in 3D models is the choice of horizontal discretisation. For problems that are governed by complex coastal boundaries an unstructured grid approach seems attractive. This paper focuses on the development of a new unstructured grid three-dimensional hydrostatic model. An efficient and highly scalable implicit solution technique is adopted for the solution of the free surface elevation and an semi-Lagrangian approach is adopted for the advection of momentum and scalars. A number of tests are presented which show that the model is capable of simulating Kelvin waves in a circular basin and the North Sea.