Tidal flow modelling using a direct minimisation method

An operational model based on an inverse method is developed for the study of tidal flow in coastal areas. Models based on inverse methods can accommodate large quantities of measured data within the model domain and do not require initial or boundary data in the state variables. These are benefits that overcome the weaknesses in conventional direct models which can be ill-posed because of inadequate boundary data which cannot make use of extensive survey data. The method described in the paper uses a direct minimisation technique, and the governing equations are included as a weak constraint on the solution. This allows the relative influences of data and equations on the final solution to be defined. The model is validated using idealised topographies in terms of data assimilation, flow diversion by topography and tidal flooding and drying over a shoal.

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