Effective Flood Control Method in River Downstream Affected by Tidal Effect Using Optimal Operation of Estuary Barrage

This article introduces an effective flood control method in the downstream of a river through the optimal operation of a barrage that is connected with a sea. A new operating model for flood control of an estuary barrage that can comprehensively evaluate the intensive discharge through the floodgates at the estuary barrage during low tide and the flood propagation process in the downstream river system is proposed. The optimization method applied to the operating model of the barrage combines a one-dimensional hydrodynamic model to analyze the flood propagation process in river channels and a search algorithm based on an iterative method to organize the maximum discharge at the estuary barrage during the ebb tide periods. The proposed method was applied to the flood control of the Taedong River downstream in the Democratic People's Republic of Korea, and its effectiveness was shown and evaluated through modeling results. By imagining the downstream boundary of the river before and after the construction of the West Sea Barrage, the inundation simulation at the Taean gauging station in the downstream of the Taedong River for floods of different average recurrence interval (ARI) was achieved by employing the proposed method.