Using particle tracking to simulate sediment transport in estuaries

Abstract

The morphology of estuaries is characterized by a complex channel-shoal pattern. Interaction between river and tidal currents produces a wide variety of sand bar types. These sand bars are not static and migrate due to residual currents. Sand bars can move into shipping channels or harbors and removing them requires costly dredging activities. Eventually sand bars may regrow and pose the same problem. Hence, understanding how sand bars develop and evolve in estuaries is of importance. Currently, already a few theories exist that predict sand bar shapes and dimensions given some estuaries properties. However, predictions are unsatisfactory compared to observations, suggesting a lack of understanding. To this end, a numerical model was set up which simulates sediment transport in a different way than usual. Instead of an Eulerian approach, particle tracking is used for the advection of sediment. Particle tracking offers additional information on the flow dynamics that is lost in the Eulerian approach. This potentially can help to improve understanding of sand bar dynamics. An outline of particle tracking and some examples of particle trajectories are presented. Furthermore a few preliminary results on the simulation of sand bars are discussed.