Optimisation based bathymetry approximation through constrained unstructured mesh adaptivity

A method for generating high quality unstructured computational meshes for applications in geophysical, and specifically ocean, modelling is presented. The method generates a three-dimensional mesh which is optimised to approximate the bathymetry to a user-specified accuracy, which itself may be defined as a function of space and bathymetry. To do this a mesh optimisation method is employed which allows the formation of highly anisotropic elements aligned with bathymetric variations of high curvature. In addition a coastal recovery algorithm, based upon feature decimation and edge recovery, is described.