Sediment Transport and Morphodynamic Modelling and Field Measurements along the Rapidly Developing Coastline

Abstract

Changes in beach morphology varies over a range of space and time scales. Waves dissipate large quantities of energy over the beach. Cross shore beach change is majorly controlled by the water level variability, near-shore currents, sediment characteristics, incident wave climate and sediment distribution across the beach profile. The kinematics of the submerged section of the beach slope mostly depends on the oscillatory motions induced by waves and the currents transporting sediments. These changes, normally short term changes in the underwater part of a beach are considered and simulated by existing morphodynamic models. Development of the foreshore part of beach slope is mainly controlled by the run-up of swash. These coastal processes are affected by coastline geometry and shelf topographic features. Present study focus on morphodynamic changes in the cross-shore direction. A numerical model is presented outlining the temporal changes of beach profile exposed to waves. Leont’yev’s (1996) model for evaluating the beach profile changes was analyzed. Modifications are made in the model for evaluating various wave characteristics in the present investigation. A study is carried out considering the run-up flow mechanisms and tired to separate the contributions from the surf zone and swash zone while estimating the total sediment flux in a beach area along the shoreline. The field measurements and observations of the dune erosion process are compared with model predictions.