Lagrangian Model for Simulating the Dispersal of Sand-Sized Particles in Coastal Waters

Abstract

A model, SandTrack, has been established to simulate movements of sand-sized particles in coastal waters within a Lagrangian framework. The model can be applied to assess the dispersal of contaminated particulate material, such as may be associated with industrial discharges or the dispersal of dredged spoil. For such applications, the Lagrangian approach is essential, as the identity of the particles is important. Although Lagrangian models that existed previously could simulate fine sediment constantly in suspension, there are certain applications, such as dealing with the movement of bed particles, in which intermittent physical processes are critical. SandTrack has been tested against field observations from the coastal waters near Dounreay, United Kingdom. The tests strengthened confidence in the model predictions and enabled appropriate values of some of the model’s main physical parameters to be set. Some features of the particle distributions simulated by SandTrack are consistent with field observations and are not achievable with simpler sediment transport models. The model’s run times are sufficiently short for simulations of particle movement in moderately large coastal areas over several decades to be practical.