A Study on the One-Dimensional Flood Numerical Analysis Method in Open Channels of Cascade Barrage Network

Abstract

Abstract Flood propagation in a river that has a network of cascade barrages is greatly influenced by the operation of the barrage floodgates that are upstream and downstream in the river. In this article, an effective flood numerical analysis method is proposed for evaluating the flood propagation process in the open channels under the complex real-time operation of floodgates at cascade barrages. The proposed model mainly uses the one-dimensional Saint-Venant equation (SVE), which incorporates upstream and downstream boundary process techniques that reflect real-time operation of floodgates and techniques for treatment of inner boundaries, such as flow of tributaries and confluence points. The real-time operation of floodgates includes the full open and partial open of floodgate in consideration of lift capacity of the crane according to time and automatic operation of floodgates for the optimal discharge considering influence of high tide and low tide. The proposed method has been validated by experiments in the Taedong River in the Democratic People’s Republic of Korea, in which six barrages from upstream and downstream in this river are taken into account. Employing the proposed method, flood routing in the channels between barrages is analyzed during the period of flooding. The validation result demonstrates that the proposed method can successfully solve the problems that arise in the analysis of flood propagation in channels of the barrage network.