Net Bottom Sediment Transport Pattern Related to Residual Currents in the Pearl River Estuary, South China

In this study, the net bottom sediment transport pattern is measured and compared with flow pattern in the Pearl River Estuary (PRE). Based on 106 bottom sediment samples taken from the PRE, the spatial distribution of bottom sediment of mean grain size μ (mm), sorting coefficient σ, and skewness SK is calculated. Then the grain size trend analysis (GSTA) was used to detect the net bottom sediment transport characteristics. The bottom sediment is transported southward and southeastward in the upper part of the estuary and northward in the lower part, while a clockwise rotation trend occurs in the central part. Furthermore, a numerical flow model, based on Princeton Ocean Model (POM), is used to modulate the hydrodynamic conditions in the PRE. The simulated long-term bottom residual currents correlate well with the GSTA results, implying that the net bottom sediment transport is mainly controlled by the residual currents.