• Journal of The Korean Society of Agricultural Engineers
• /
• v.48 no.2
• /
• pp.27-35
• /
• 2006

Large dams are managed with operation standard and flood forecasting systems, while small dams do not have management method generally. Shortage of water resources and natural disasters due to drought and flood raised public concerns for management of small dams. Most of small dams are irrigation dams, which need diversified water uses. However, the lack of systematic management of small dams have caused serious water wastage and increased natural disasters. Storage management method and system were developed to solve these problems in small dams. The system was applied to Seongju dam for effective management. The storage management method was established considering hydrology simulation and statistical analysis using the system. This method can bring additional available water, even in the same conditions of the water demand and the supply conditions of watershed. It can improve the flood control capacity and water utilization efficiency by' the flexible operation of storage space.

• Journal of Wetlands Research
• /
• v.20 no.4
• /
• pp.353-362
• /
• 2018

The purpose of this study is to suggest a structure plan for improving the utilization of inactive storage in the dam for overcoming the drought. Inactive storage in the dam is composed of the emergency storage and dead storage. The emergency storage can be used for the case of emergency such as drought. But, in general, the dead storage for sedimentation is not used even for the emergency. Therefore, this study considers the part of dead storage that the sedimentation is not progressed yet can be used during the severe drought period and is called "drought storage in a dam". The accurate Sediment Level(SL) analysis for the computation of the drought storage should be performed and so the present and future SL in the dam reservoir is estimated using SED-2D linked with RMA-2 model of SMS. After the consideration of additionally available storage capacity based on the estimated SL, the drought storage is finally determined. Present data based on historical data, future predicted future climate factors by Representative Concentrarion Pathways(RCP) 8.5 scenario. Then, using the TANK model, dam inflows were determined, and future period such as SL and drought storage were suggested. As the results, we have found that the available drought storage will be reduced in the future when we compare the present drought storage with the future one. This is due to a increase variability of climate change. Therefore, we should take the necessary study for the increase of available drought storage in the future.

• Journal of the Korean Society of Safety
• /
• v.38 no.2
• /
• pp.81-86
• /
• 2023

In this study, a one-dimensional numerical model was constructed to propose a flood control plan linked with the dam and river basin for the flood events of the Seomjin River in 2020. The flood level reduction of the downstream river was tested based on a scenario operation of the Seomjingang Dam and was also analyzed when a storage pocket was newly constructed as one of the river basin measures. It was confirmed that Seomjingang Dam's flood control capacity would be increased if the flood limit level was drastically lowered from the current EL. 196.5 m to EL. 188.0 m. In addition, if the upper area of the (old) Geumgok Bridge (which suffered great damage due to the loss of the levee) is used as a storage pocket, it would be effective in preventing floods in the lower area of it. In the era of the climate crisis, more integrated flood management is needed and basic river management must be observed.

• Journal of Wetlands Research
• /
• v.11 no.3
• /
• pp.115-132
• /
• 2009

We defined a dam as a wetland for assessing wetland functions of man made dam. We compared Boryung dam with Upo wetland by HGM assessment. Hydrologic functions of Boryung dam are not good at short term water storage, but good at long term water storage. Biogeochemical functions of Boryung dam are about 50% of Upo wetland's functions. Boryung dam is a good wetland as a plant habitats and animal habitats. But functions as a habitat for birds were not good. With this study we look forward to making clear merits and demerits of Boryung dam’s functions as a wetland.

• Korean Journal of Hydrosciences
• /
• v.5
• /
• pp.17-31
• /
• 1994

Because of the Keumkangsan-Dam and the Peace-Dam constructed in recent years, it is expected that the peak flood discharge and the peak flood stage at the Hwachun-Dam site have been changed. In this study, two methods were used to simulate and compare the effects of the upstream dam construction on the change of the discharge and the stage. One is the storage function method widely used for the hydrological routing in the country. The other is the DWOPER(Dynamic Wave Operational Model) package conducted on four different scenarios: (1) before the construction of the Keumkangsan-Dam and the Peace-Dam; (2) the exclusion of the Keumkangsan-Dam watershed (before the construction of the Peace-Dam); (3) the exclusion of the Keumkangsan-Dam watershed (after the construction of the Peace-Dam) ; (4) the exclusion of the Peace-Dam watershed. The results of the four test cases from the two methods show that the peak flood discharge and the peak flood stage at the Hwachun-Dam site are reduced due to the construction of the Peace-Dam. From these findings, it is suggested that the operational criteria for the optimal dam-operation of the Hwachun-Dam need to be modified.

• Journal of Korea Water Resources Association
• /
• v.57 no.4
• /
• pp.301-310
• /
• 2024

The spatial and temporal non-uniform distribution of precipitation makes water management difficult. Due to climate change, nonuniform distribution of precipitation is worsening, and droughts and floods are occurring frequently. Additionally, the intensity of droughts and floods is intensifying, making existing water management systems difficult. From June 2022 to June 2023, most of the water storage rates of major dams in the Yeongsan river and Seomjin river basin were below 30%. In the case of Juam dam, which is the most dependent on water use in the basin, the water storage rate fell to 20.3%, the lowest ever. Pyeongnim dam recorded the lowest water storage rate of 27.3% on May 4, 2023. Due to a lack of precipitation starting in the spring of 2022, Pyeongnim dam was placed at a drought concern level on June 19, 2022, and entered the severe drought level on August 21. Pyeongrim dam and Suyangje(dam) have different operating institutions. Nevertheless, the low water level was not reached at Pyeongnim dam through organic linkage operation in a drought situation. Pyeongnim dam was able to stably supply water to 63,000 people in three counties. In order to maximize the use of limited water resources, we must review ways to move water smoothly between basins and water sources, and prepare for water shortages caused by climate change by establishing a consumer-centered water supply system.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.47 no.3
• /
• pp.15-25
• /
• 2005

Ninety tow percent of over 1,800 gate controlled dams in Korea are classified as small dams. The primary purpose of these small dams is to supply irrigation water. Therefore, while large dams can store as much as 80 percent of precipitation and thus are efficient to control flood, small dams are often lack of flood control function resulting in increased susceptibility drought and flood events. The purpose of this study is to develope a storage management model for irrigation dams occupying the largest portion of small dams. The proposed Storage Management Model (STMM) can be applied to the Seongju dam for efficient management. Besides, the operation standard is capable of analyzing additional available water, considering water demand and supply conditions of watershed realistically. And the model can improve the flood control capacity and water utilization efficiency by the flexible operation of storage space. Consequently, if the small dams are managed by the proposed Storage management model, it is possible to maximize water resources securance and minimize drought and flood damages.

• Journal of Korea Water Resources Association
• /
• v.31 no.1
• /
• pp.95-103
• /
• 1998

Dam sediment can be predicted from the two methods: the one is a physical analysis based on the hydrjulic mechanism and the other is an empirical approach using observed data as a design factor. The former can be used to estimate short-term phenomena by mathematical methods. the latter can be used for deriving long-term design parameters such as dead storage calculation. Monthly reservoir operation is possible with the sluicing efficiency curve based on empirical data. The optimal sediment management can be carried out using the information variable which traces deposit sediments corresponding to the reservoir storage. The idea can provide an optimal operation strategy to save effective storage varying with time. This study presents a methodology for the long-term sediment prediction using sluicing efficiency curve. An application is conducted for estimating accumulated sedment deposit and water supply capability ofr the Fenhe dam in the Yellow rever of China.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.55 no.6
• /
• pp.57-68
• /
• 2013

About 74 % of reservoirs in Korea are older than 40 years and their storage capacities have been decreased substantially. As part of reservoir reinforcement, the dam heightening project has been ongoing for about 110 reservoirs. The main purpose of the dam heightening project is to secure additional environmental water, while improving flood control capacity by gaining additional storage volume. The objective of this study was to evaluate reservoir flood control capacity changes of dam heightening reservoirs for effective management of additional storage volume. In this study, 13 reservoirs were selected for reservoir simulation of 200 year return period floods. Rainfall data of 1981-2100 were collected and divided into 4 periods (1981-2010; 1995s, 2011-2040; 2025s, 2041-2070; 2055s, 2071-2100; 2085s). Probability rainfalls and 200yr design floods of each period were calculated using FARD2006 and HEC-HMS. Design floods were used as inputs of each reservoir simulation using HEC-5. Overall, future probability rainfalls and design floods tend to increase above the past 1995s. Control ratios were calculated to evaluate flood control capacities of reservoirs. As a result, average flood control ratios were increased from 32.6 % to 44.2 % after dam heightening. Control ratios were increased by 12.7 % (1995s), 12.4 % (2025s), 10.3 % (2055s) and 10.9 % (2085s). The result of this study can be used as a basis for establishing the reservoir management structure in the future.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1999.04a
• /
• pp.619-624
• /
• 1999

The purpose of this study is to provide the optimum mix design of fly ash concrete to be placed at the concrete face rockfill dam for pumped storage power plats. The basic performance tests including compressive strength, modulus of elasticity, unit weight, coefficient of thermal expansion, shrinkage, adiabatic temperature rise and analysis of thermal stress were conducted for fly ash concrete. From this study, the fly ash concrete represented the better results in the aspects of basic performance and economy than ordinary portland cement concrete. Especially the concrete mix design containing 15% of fly ash is recommended to be applied in the construction of the concrete face rockfill dam for pumped storage power plants.