Study on dynamic balance characteristics of the Modaomen estuary of the Pearl River and impacts of human activities

The ECOMSED model output and the simplification of the Reynolds equation are employed in this paper to study the characteristics of the dynamic balance of the Modaomen Estuary of the Pearl River.The study shows that the longitudinal component of the pressure force is mainly balanced by the vertical eddy frictional term and the lateral component of the pressure force is mainly balanced by the Coriolis force.The barotropic force is the dominant dynamic factor in the Modaomen estuary,but the baroclinic force is also important during the dry season.The most important impact of the human activities on the estuarine dynamics of the Modaomen estuary lies in altering the barotropic force,which decreases generally in recent decades.