A Triangular Coastal Element for Finite Difference Tidal Models
by
David McInerney
Department of Applied Mathematics, University of Adelaide
Coauthors: John Noye (University of Adelaide)

In numerical models of environmental flows it is often necessary to implement impermeable boundaries of complicated shape. For example when modelling the spread of pollutants in streams, the dispersion of contaminants in lakes and estuaries or the final coastal destination of an oil spill, the land-water boundary is not simply defined. Currently such boundaries are most accurately represented using Finite Element (FE) techniques. However FE techniques are both computationally expensive and difficult to implement. As a result Finite Difference Methods (FDMs) on rectangular grids have traditionally been used to model environmental flow.

In this paper a triangular boundary element for finite difference models, which improves boundary resolution while maintaining computational efficiency, is introduced. In particular a triangular element for tidal models in coastal regions is developed and tested. Impressive numerical predictions using the new approach are compared with predictions obtained using the traditional stepped boundary and an analytic solution for depth-integrated flow in an idealised estuary.

Date received: July 29, 1999

Copyright © 1999 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # cadk-67.