Modeling the Shore-Normal Profile Shape Evolution for an Accretional Tidal Flat on the Central Jiangsu Coast

The evolution of the shore-normal profile shape of an accretional tidal flat is controlled by the transport of muddy and sandy sediments by tidal currents.To understand the evolution processes,a model is established to simulate the tidal flat profile changes in response to spring-neap tidal cycles,and it is applied to the accretional tidal flat on the central Jiangsu coast to investigate the interrelationships between the initial profile shape of the inter-tidal flat,tidal range,sediment supply,the equilibrium profile shape of the intertidal flat,and the long-term behavior of a prograding profile.The modeling output indicates that:(1)the shape of the accretional tidal flat tends to be convex when reaching its equilibrium state;(2)equilibrium of the intertidal flat morphology is independent of the initial profile shape;(3)if the sediment supply remains stable,then the width of the intertidal flat is positively correlated to tidal range;(4)the width of the intertidal flat increases with sediment supply and the accretion or erosion status of the intertidal flat is determined by sediment supply;(5)there is a need to design an algorithm to treat the area close to high water on springs to simulate long-term growth of the tidal flat;(6)the intertidal flat associated with abundant sediment supply will progradeg towards the sea,and at the same time its equilibrium shape will be maintained;and(7)the width and gradient of the intertidal flat from the model output are consistent with those of the Jiangsu coast,when inputting parameters derived locally for the model.