Responses of estuarine circulation to the morphological evolution in a convergent, microtidal estuary

Abstract. The Huangmaohai estuary (HE) is a funnel-shaped microtidal in the west of Pearl River Delta (PRD) southern China. Since China reformed and opened up 1978, extensive human activities have occurred greatly changed estuary's topography modified its hydrodynamics. In this study, we examined morphological evolution by analyzing remote sensing data with ArcGIS tools studied responses hydrodynamics to changes from 1977 2010 using Delft3D model. We took estuarine circulation during neap tides dry seasons as an example. results show that reclamation caused narrowing estuary, channel dredging deepened estuary. These both longitudinal lateral circulations. was observed increase deepening experienced magnitude pattern. momentum balance analysis shows when depth width simultaneously, modulated reduction, which friction, pressure gradient force, advection terms were altered. vortex dynamics indicates vertical shear flow, salinity gradient, mixing responsible for change circulation. water are dominant factors affecting intensity. This study has implications sediment transport estuaries heavily impacted interventions.