Multiscale physical processes of fine sediment in an estuary

Abstract

This study presented in this book investigates micro- and macro- scale physical processes of a large-scale fine sediment estuarine system with a moderate tidal range as well as a highly seasonal-varying freshwater inflow. Based on a series measured, experimented and modeled results, the research highlights that (i) along-channel fresh-salt gradient near an estuarine turbidity maximum zone is a key parameter controlling local density stratification and sedimentation in the channel; (ii) the salinity-induced baroclinic pressure gradient forces are a major factor impacting internal velocity and suspended sediment concentration (SSC) structures; (iii) vertical profiles of current, salinity and SSC within a river plume are dependent on a correct prediction of the development of turbulence; (iv) both suspended particulate matter availability and local residual flow regime are of critical importance for trapping probability of sediment and the occurrence of fluid mud; (v) river discharge impacts the horizontal and vertical distribution of residual current; (vi) seasonally varying wind effect alters the residual currents near the riverine limit; (vii) seasonally varying mean sea level and wind climate jointly shape the saltwater intrusion length near the estuarine front.