Effective flood control method in River Downstream affected by Tidal Effect Using Optimal Operation of Barrage Reservoir


Chairman Kim Jong Il said:

"We should build a large number of structures such as dams and barrages on rivers and take good care of them. Only then can we prevent damage from flooding and add beauty to the landscape of the country as well."

Building and taking good care of various structures such as dams and barrages on rivers is a very important and key issue for preventing damage from flooding and making rational use of water resources.

The Faculty of Geo-environmental Science, Kim Il Sung University has proposed a method of controlling flood in the downstream region while ensuring the safety of dams of the barrage reservoirs built in the tidal rivers during the flood and made achievements in the field of flood control in the barrage reservoirs.

Generally, the reservoir discharge process for flood control is performed by opening and closing the gates of the reservoir.

However, in the barrage reservoirs built in the estuary of the river, the effect of tides makes it impossible to discharge by opening the gates when the reservoir level is below the tidal level.

Considering the tidal effects during flooding and optimizing the gate discharge process depending on the time to prevent flood damage in the downstream area is a key issue in the management of the reservoir flood.

The researchers proposed a new flood optimization model that can comprehensively estimate the discharge through the gates of the barrage reservoir and the flood propagation process at ebb tide.

The optimization method applied to the operating model of the barrage reservoir is combined with a one-dimensional hydrodynamic model to analyze the flood propagation process in the river channel and determine the optimal discharge at ebb tide by a search algorithm.

The proposed method was applied to flood control in the West Sea Barrage Reservoir built on the lower River Taedong, and the model results verified the effectiveness of the method.

The flood inundation simulations were carried out for different recurrence periods at the observation point downstream the River Taedong, assuming the river downstream boundary before and after the construction of the West Sea Barrage.

The validation results show that the proposed method fully reflects the requirements of reservoir controllers and it can effectively be applied to the determination of the optimal operating rules of tidal-affected barrage reservoirs during floods.

In this way, the structures of barrage reservoirs built on the tidal river can be safely protected from floods, while the reservoir level can be lowered to prevent flood inundation in the downstream areas.

The result of this study was published in the "Journal of Waterway, Port, Coastal, and Ocean Engineering", under the title of "Effective flood control method in River Downstream affected by Tidal Effect Using Optimal Operation of Estuary Barrage" (