Evaluation Of Channel Regulation Project In Dewatering Section Under Cascade Junction Dam

Hydropower development has led to the channelization of natural river channels,and the navigation flow under the dam has not been guaranteed.The dewatering section under the dam has become a bottleneck restricting the development of shipping.Due to the complexity of the renovation project under the dam,there are still many natural phenomena and their internal mechanisms that have not yet been fully understood and mastered.It is of practical value to predict the flow field of the dewatering section under the dam of the cascade hub after the implementation.Taking the channel of the dewatering section under the dam of Shaxikou Hydropower Station as an example,the threshold water level of the lock is raised,through in the dewatering section under the dam the construction of the diversion dam,artificial uncovered canal,closure dike,spur dike.And at the same time,the continuous reverse corner under natural conditions is straightened by taking dredging,underwater blasting works and other engineering measures to increase the bending radius and smoothing.The route ensures the safety of the ship.Based on the structured grid and finite volume method,the mathematical model of the channel improvement project of the Shaxikou hydropower dam of the Minjiang River is established.The hydrodynamic characteristics of the river channel depth,water level,velocity,flow field and flow regime under the conditions of 265 m~3/s,1000 m~3/s,1800 m~3/s and 3000 m~3/s designed flow rate before and after channel regulation respectively are analyzed.The impact of the remediation project on the water level and flow rate,and the impact of the remediation project on flood discharge.The research results have laid a good foundation for the rectification of other sections of the Minjiang River resources.It is of great scientific significance for improving the supporting facilities of the Minjiang River Channel,ensuring navigation safety and improving the navigation environment.At the same time,the research results can also provide experience and reference basis for waterway regulation of dewatering section under the same cascade dam.