ON MODELLING BEACH PROFILE EVOLUTION

Harshinie Karunarathna, Dominic E Reeve, Mark Spivack

Abstract


Behaviour-oriented beach evolution models are normally applied in a prognostic fashion, with model parameters and boundary conditions estimated from previous experience, other forecasts or from historic measurements. Here, we use observations of beach profiles to solve a cross-shore beach profile evolution equation in an inverse manner to determine key model parameters, cross-shore sediment diffusion coefficient and a time-varying source function. The data used to demonstrate the method are from Christchurch Bay in Dorset, United Kingdom. It was found that there is a significant contribution from diffusive processes to the morphodynamic variability of the beach profiles and that the development and disappearance of cross-shore coastal features such as upper beach berms and inter- and sub-tidal bars are well captured by the time-varying source function in the governing equation.

Keywords


coastal morphology, beach profiles, inverse method, behaviour-oriented models

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