Abstract: The regime in the north channel of Yangtze river estuary has changed remarkably after the implementation of deepwater channel regulation projects. Variations in the riverbed morphology and water depth will affect the tidal wave propagation. In view of this, a mathematical model of Datong-offshore was built through unstructured grid FVM to research the impacts of deepwater channel regulation projects at Yangtze river estuary on the tidal propagation. Results show that tidal wave propagation in the north channel changed little after the first phase of the project due to small engineering quantities. But after the second phase, the high tide level rose slightly while low tide level rose remarkably. The tidal wave propagation kept consistent after the third phase. The loss of tidal wave energy is caused slightly by jetties but mainly by groin works.

Key words: Yangtze river estuary, mathematical model, north channel, tidal wave propagation, tide level