Abstract:

Based on previous studies,the characteristics of saltwater intrusion of the South Branch of the Changjiang Estuary were studied systematically by the analysis of measured saltwater intrusion and chlorinity data.Results indicate that the saltwater which spills over from the North Branch is the main source of the salt intrusion of the South Branch.In the study area,the distribution of chlorinity during dry season’s spring tide appears as a twosidehigh and middlelow’s saddle shape,while the distribution of chlorinity during dry season’s middle tide appears as a highlowhighlowhigh’s ‘W’ shape.Because of the effects of tide and upstream’s discharge,the distribution shape of chlorinity has varied from spring tide to middle tide.The intensity of the salt intrusion of the South Branch tends to be much more serious since 1998;the salt intrusion of the South Branch is much more serious during February and March than other months;the salt intrusion of the South Branch may take place when the discharge from Datong station is less then 20 000 m3/s.There are close relationships between discharge from Datong station and tidal strength;larger the discharge,lower level of the salt intrusion;greater the tidal range,higher level of the salt intrusion