A Method for Automating the Construction of Irregular Computational Grids for Storm Surge Forecast Models
Irregular grids for computing storm surges can be generated from digital data defining the bathymetry and boundaries of the basins in which the surges occur. The method presented here for constructing these grids proceeds in two stages. First, a curvilinear grid is constructed to have boundaries which coincide with the curving coastlines of bays and barrier islands. In the second stage, a fully irregular grid is constructed by removing points from the curvilinear grid. Because the separation of neighboring points is proportional to the square root of the basin depth, the irregular grid provides for economical computations with a minimum of numerical dispersion. This method can be generalized for other purposes. It is possible to construct grids comprised of quadrilateral or triangular elements, corresponding to both curved and planar domains, to be used for a wide variety of calculations using either finite-difference or finite-element methods.