Influence of the Three Gorges Project on saltwater intrusion in the Yangtze River Estuary

The Three Gorges Project (TGP) is a transcentury project that has aroused world attention. It is expected that the flow velocity and runoff of the Yangtze River will be changed after the project has been accomplished. Consequently, however, the ecological environment in the Yangtze River Basin, particularly in the estuary region, will be affected. Salinity intrusion into the Yangtze River estuary, in general, is mostly affected by the Yangtze River discharge and its external tidal level. This paper focuses on examining the influence of changes in runoff on salinity value. The question, to which should be paid attention is: how is the interaction between changes in runoff of the Yangtze River and salinity distribution in the Yangtze River estuary, China? In this research, a three-dimensional model has been used to identify the effects of runoff change on salinity distribution. The drawn conclusion is that the change of salinity is influenced by discharge variation. Positive and negative impacts of TGP would both turn up but in different period. In sum, TGP is in favor of restraining saltwater intrusion. Nevertheless a suitable method should be found to resolve its negative influences.