Author(s): Huazhi Zou, Shunchao Yu, Liangliang Zhang
Linked Author(s): ZOU Huazhi
Keywords: Estuary, circulation, saltwater intrusion, numerical model, riverbed degradation
Abstract: In order to study the impact of the riverbed degradation on the saltwater intrusion in the Pearl River Estuary (PRE), a three-dimensional baroclinic numerical model with high-resolution grids was firstly set up based on the Finite Volume Coastal Ocean Model (FVCOM) and calibrated against measured data. Results indicate that the numerical model can properly capture the dynamic processes of saltwater intrusion in both well mixed and stratified rivers. Secondly, numerical experiments of saltwater intrusion in the PRE were carried out by inputting several sets of data of topographic survey in different years. Results show that the large-scale riverbed degradation leads to an obvious increase in the strength of the saltwater intrusion in the PRE and the scenario of saltwater intrusion is worse in stratified rivers than that in well mixed rivers even though they have similar change of water depth. Finally, the hydrodynamic characteristics of saltwater intrusion were analyzed according to simulated results from different numerical experiments and synchronous measured data. It seems that the larger water depth due to the riverbed degradation will enhance the vertical circulation along the longitudinal direction especially in the stratified rivers. As a result, both the upstream intrusion of near bottom high-salinity water and the downstream diffusion of surface diluted water are accelerated. These increased the amount of upstream transportation of salinity and thus greatly contributed to the worse scenario of saltwater intrusion in the PRE
Year: 2017