Model-based interpretation of sediment concentration and vertical flux measurements in a shallow estuarine environment

A one-dimensional numerical model describing tidally varying vertical mixing and settling was used to interpret sediment concentrations and vertical fluxes observed in the shoals of South San Francisco Bay by two acoustic Doppler velocimeters (ADVs) at elevations of 0.36 m and 0.72 m above bed. Measured sediment concentrations changed by up to 100 g m⁻³ over the semidiurnal tidal cycle. These dynamics were dominated by local resuspension and settling. Multiple particle class models suggested the existence of a class with fast settling velocities (w_s of 9.0 × 10⁻⁴ m s⁻¹ in spring and 5.8 × 10⁻⁴ m s⁻¹ in fall) and a slowly settling particle fraction (w_s of