Evaluation of the effects of sediment characteristics on long-term estuarine morphological modelling driven by waves and tides

Abstract

Tidal basins are made of several elements that have achieved morphological equilibrium and have been affected by hydrodynamic forces over the centuries with its present form. In addition to the effects of hydrodynamic forces, morphological equilibrium is also affected by the sediment parameters. In this study, the effects of sediment characteristics on the long-term morphology of tidal basins were evaluated. A realistic analogue method was used to illustrate the final form of basin morphology after reaching the equilibrium. Also, the effects of important sedimentary parameters were evaluated to provide the long-term forecast of the morphology comprehensively. Instead of trying to replicate the exact conditions in a particular period of time, the present study aimed to directly investigate the process and effects of the main parameters.In this study, Tiab estuary was considered as a numerical laboratory and enough observations were produced to assess the impact of sedimentary parameters on the morphological equilibrium. In this research, a realistic method was used to model the bed by assessing the impact of morphological changes. The assessment of sedimentary parameters was carried out in the presence of two main hydrodynamic components: wave and tide. Given the computational cost of the long-term morphology models and numerous models needed to evaluate the sediment parameters, statistical methods were used to design the optimal scenarios which is a new method in the analysis of morphological information. A comparison of the model's results and the measured hydrography revealed the validity of the proposed method.