Evaluation of the storage effect considering possible redevelopment options of the peace dam in South Korea

The PeaceDamis one of two flood control dams in South Korea. Located near the demilitarized zone (DMZ) between North and South Korea, the Peace Dam was constructed as a counter measure to the Imnam Dam of North Korea. However, the recent reconciliation efforts between North and South Korea have raised the possibility for the redevelopment of the Peace Dam to be a multi-purpose dam. This study evaluates the possible increase of the flood control ability of the Peace Dam under the condition of its redevelopment. The allocation of flood control and water conservation storage as well as the reservoir operation method is determined to follow the other similar-sized dams in Korea. The flood control ability is quantified by introducing the concept of a storage coefficient. In order to estimate the storage coefficient, an exponential nonlinear reservoir model was used. The results can be summarized as follows: First, the current Peace Dam, a flood control dam, is found to have a small flood control ability. Quantified by the storage coefficient, the flood control ability of the current Peace Dam is estimated to be just 3.9 h. Second, the maximum storage coefficient of the Peace Dam can be increased up to 22.6 h. Here, it is assumed that the dam is operated by the rigid reservoir operation method (rigid ROM) in which the discharge is determined by applying a constant rate (specifically, 0.5 in this study) to the inflow until the peak inflow is reached. In addition, this result is based on the assumption that the ratio between water conservation storage and flood control storage is three. That is, even though the flood control storage is set at just 25% of the total storage, the storage coefficient is increased to be more than five times that of the current Peace Dam. In addition, secured water conservation storage can significantly increase the benefits associated with the redevelopment of the Peace Dam.