Research on reverse order impoundment mode of cascade reservoir flood control system: Case study on upper reaches of Yangtze River

•Activation and allocation of flood control capacity for the cascade reservoir.•The 'reverse order impoundment method of cascade reservoir' mode was proposed.•The improved artificial bee colony algorithm was adopted to solve the optimal model.•The flood control standard downstream was improved greatly.•The peak inflow to the Three Gorges Reservoir was reduced.