A three - dimensional numerical model, Estuarine, Coastal and Ocean Modeling System with Sediments（ ECOMSED）, is em- ployed to study the mechanism of plume front in the Pearl River Estuary （PRE） indetail. The model is forced by winds, tides and river discharges. The results were in reasonable agreement with observational data in the PRE. By analyzing momentum and saltwater trans- port balance equations, it was found that the wind stress term, the pressure gradient term and the local time derivative term of velocity were dominant in the momentumequation, while the local time derivative term, the horizontal advective term and the vertical mixingterm of salinity were dominant in the salinity transport equation. The residual current at surface was seaward and stronger, whilst the bottom layer was mainly landward. Anincrease in the river discharge at Dahu inlet seemed to affect the location of plume front obviously among four river inlets. The effect ofriverdischargeincreasein Nansha or Fengmamiao inlet on the plume front of PREwas more local and wea- ker, whilstthe increase of river discharge at Hengmen inlet had little effect on the plume front. Also, it showed that thestronger or more northward winds were, the more westward plume front moved, and the difference between wind speed and wind direction on plume fro- ntwas concentrated in the northern area of PRE.
Wind - driven currents
Pearl River Estuary