Modelling coastal sediment transport on a parallel computer

Abstract

The movement of suspended sediments in estuaries and coastal environments cause many problems, e.g. siltation of navigation waterways, harbours and coastal environments. The transport of sediment in a tidal environment is rather complex. This is due to the complexity of the coastal hydrodynamics and the interaction of the sediments with the flow. Numerical simulations of the tidal flow and sediment transport are useful tools for planning, design and management. Computations become expensive when the flow model and the sediment transport model are coupled, especially when the computations are done with small grid sizes. In this paper we describe a coupled model for the Belgian coast area, where a grid size of 75 m ∗ 75 m is needed to resolve the complicated bathymetry. In order to improve the performance of the coupled model, the codes have been modified to run on a parallel computer (IBM/SP2). The modification includes a transformation from FORTRAN 77 code into FORTRAN 90. The MPI communication library is used for exchanging information between the processors. The model results and the performance on the IBM/SP2 machine are presented and discussed.