A long-term (decadal scale) evolution model for microtidal barrier systems

Abstract: A model is presented to simulate the long-term (decadal) evolution of microtidal spit-barrier systems. The model has been derived from the analysis of coastal processes taking place along the Trabucador-La Banya complex in the Ebro delta (Spanish Mediterranean coast). It is composed of two submodels to simulate the evolution of the seaside and bayside barrier shorelines. The outer coast submodel is of the one-line type, but formulated in curvilinear coordinates to reproduce the evolution of strongly curved coasts, which is a common configuration for spits. The model makes use of a long-term parameterization of the longshore sediment transport rate, which is formulated in terms of a morphological wave and a local transport constant. The inner coast submodel is based on a morphological equilibrium approach. It considers the overwash transport to be the dominant driving term contributing to the sediment budget of the inner coast. It makes use of the concept of critical barrier width to estimate the conditions under which overwash is able to contribute to bayside shoreline accretion. The model has been verified/calibrated for the Trabucador-La Banya system and it has been used to simulate its evolution under different climatic scenarios. [Copyright &y& Elsevier]