Study on Activities and Concentration of Saline Groupin the South Branch in Yangtze River Estuary

Abstract

A two-dimensional hydrodynamic force-salinity transport model in Yangtze River Estuary is established on the basis of analyzing the measured data and the adoption of MIKE21 model. This model is used to study the average daily distribution and changing patterns of the saline groups in the South Branch that are from the North Branch while only the saltwater intrusion from the North Branch is considered; It determines the intrusion process of saline groups (i.e. salinity water lenses)from the North Branch and the area that are affected by saline groups intrusion; in addition, the patterns and mechanisms of saline groups flows in various waterways in the South Branch are revealed by studying the downward movements and salinity changes of the core saline groups in the waterways of South Branch. The saltwater intrusion from the North Branch has a great influence on the longitudinal, horizontal and vertical salinity fields in the Yangtze River estuary. While the flows are different, the relationship between the average position of the tidal cycles of the saline group’ cores and the time conforms to Gompertz model, and there is a nonlinear relationship between its parameters and the flows.