We are pleased to have the opportunity to continue the discussion of mathematical modeling of coastal processes with Cowell and Thom (2006). Our respective views can be succinctly summarized as follows: Our view is that quantitative modeling of coastal processes with sufficient accuracy for most engineering and planning purposes is impossible. We do believe that qualitative modeling—answering the how, why, and what-if questions—can be useful. Cowell and Thom on the other hand believe that accurate predictive modeling of coastal evolution is feasible on a scale useful to engineers and coastal managers and that coastal managers require such predictions to do their work.
To make their point, Cowell and Thom cite a number of “successful” modeling efforts in Australia and elsewhere. We argue that their examples do not prove their point for two reasons.
Hindcasting is not forecasting. Their evidence of model success is therefore less than convincing. Hindcasting is...
