The Use of Open Boundary Conditions With the Storm-Surge Equations

Open boundaries are desirable when the region of interest of a computation is a localized area of a much larger domain. Boundary conditions are developed for the linear storm-surge equations (without Coriolis effects) that permit disturbances to pass out of the region of computation with negligible reflection. These conditions, based on the concept of Riemann invariants, are applied in one- and two-space dimensions. Examples of the flow around a sea mound, a shelf, and an island are given. Selected comparisons are made with Sommerfeld's radiation condition, advanced by Vastano and Reid.