Types of saltwater intrusion of the Changjiang Estuary

The Changjiang Estuary is characterized by multi-order bifurcations, unstea dy submerged sandbars, mid-channel sandbars, creeks and riffles. The follow ing four types of saltwater intrusion are found: (1) direct intrusion from the sea; (2) intrusion during tidal flooding; (3) intrusion from tidal flat s overflow; and (4) salt water coming upstream through other waterways. The se re-suit in a complicated temporal and spatial salinity distribution. A h igh chlorinity concentration zone exists from the Liuhekou to the Sidongkou along the South Branch. The salinity during neap tide or ordinary tide is higher than during spring tide.