Dynamic Stability and Optimal Design of Intertidal Sandbars due to the Feedback Between Sediment Transport and Suction Dynamics Effects

Abstract

The persistent nature of intertidal sandbars was the subject of much speculation concerning the hydrodynamic mechanisms involved, but its origin remained enigmatic. We recently found on the basis of the geophysical evidence and theoretical modeling and analysis that the interplay between the effects of the dynamics of suction and sediment transport and morphology plays a crucial role in such intertidal sandbar morphodynamics. Here we further clarified this mechanism in light of artificially created sandbars in Tokyo Bay, by performing integrated observations and analyses of the morphological and geoenvironmental changes as well as the benthos diversity and stratigraphy variations, combined with a series of laboratory soil tests. The results highlight the salient geophysics that arise from the feedback between sediment transport and the suction dynamics effects, and give rise to an optimal design of such dynamically stable sandbars as habitats with diverse ecological activity.