Risk decision of construction diversion schemes under condition of pre-discharge at cascade hydropower stations

In construction of cascade hydropower stations,through pre-discharge at the upstream stations that cuts flood peak and floodwater storage,the construction flood of the downstream station to build will also be reduced and the flood control condition and other characters of the construction diversion system are changed.In light of such a situation,this paper systematically examines the causes of construction diversion risk and its coupling relation and develops a measure model of diversion risk based on simulation technology.We studied the benefit transfer between upstream station and downstream diversion project,put forward a strategy for calculating the coordinated distribution of diversion system gain and loss,and developed a model for optimization of construction diversion schemes using the coordinated distribution of gain and loss.In this model,double goal optimization is singled by a utility function and system benefit utility is used as a comprehensive index to measure the quality of diversion schemes.An example is presented to verify the presented approach.This study is useful for selecting a diversion scheme in cascade hydropower development.