Study of the effect of turbulence on the properties of flocculated mud

Abstract

For the successful management of an estuary, an accurate simulation model predicting sediment transport patterns is a necessity. This requires a knowledge of the vertical mass settling flux (MSF), which is the product of the suspended particulate matter (SPM) concentration and the settling velocity (Ws). However the presence of cohesive sediments (i.e. mud) complicates this description due to the ability of mud particles to flocculate into larger aggregates (floes) which demonstrate faster settling velocities and lower effective densities (pe) than the component cohesive particles. The generation of turbulent shear stress (TSS) within the water column is regarded as having a controlling influence over the structure of floe populations. A poor understanding of cohesive sediment settling fluxes has existed due to the severe lack of coherent in-situ floe and hydrodynamical data.