Encountered regulation rereareh on upstream flood of Yangtze River with Dangting Lake flood

Flood from its main stream and branches encountering together is the main reason of serious flood in Yangtze River.Now the Three Gorges Project has been build,which has huge and compositive benefits such as flood control,power generation,navigation,irrigation,water supply and economic development in the reservoir area,and has a special important significance for the safety of flood control in the mid-down stream.To provide research foundation for optimizing the regulation scheme of the Three Gorges Project and make the best use of its huge flood-control capacity,this paper focus different magnitudes from Yangtze River upstream and Dongting Lake by the hydrological analysis method,from the roles as encounter frequency,encounter time,encounter magnitude and peak discharge,flood volume and soon.