• Journal of the Korean Society of Hazard Mitigation
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• v.4 no.1 s.12
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• pp.33-40
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• 2004

The objective of this study is to develop single dam operation models for flood control using Fuzzy control technique, which can improve flood controllability. We set control rules by water level and inflow, and developed three models Fuzzy I, II, III according to rule to decide outflow. Fuzzy I model consists of six rules considering only flood control and Fuzzy II model considers the effect of water use by increasing water level at the end of flood control period as well as flood control during the same period. Finally, Fuzzy m is an adaptive model designed to perform multipurpose dam operation for both flood control and water use simultaneously based on a control rules.

• Water for future
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• v.30 no.2
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• pp.34-37
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• 1997

• Korean Journal of Hydrosciences
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• v.7
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• pp.37-49
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• 1996

This study aims at suggesting an alternative to improve flood controling capacity according to the cument design criteria for the existing Soyanggang Multi-purpose Dam which was constructed 20 years ago as the largest dam in Korea. The peak inflow of the adopted probable maximum flood (PMF) at the time of construction was 13,500 $m^3$/s. However, the newly estimated peak inflow of the PMF is 18,000 $m^3$/s which is 1.34 times bigger than the original one. This is considered to be due to the accumulation of the reliable flood and storm event records after construction, and due to the increasing tendency of the local flood peaks according to the influence of world-wide weather change. The new estimation of the probable maximum precipitation (PMP) was based on the hydro-meteorological method suggested by the guideline of the World Meteorological Organization (WMO). The unit hydrograph which was applied for the estimation of PMF was derived through linear programming algorithm by minimizing the sum of absolute deviations of the calculated and recorded flood hydrographs. In order to adopt the newly estimated PMF as a design flood, following four alternatives were compared : (1) allocation of more flood control space by lowering the normal high water level, (2) construction of a new spillway in addition to the existing spillway, (3) construction of a new dam which has relevant flood control storage at the upstream of the Soyanggang dam, (4) raising the existing dam crest. The preliminary evaluation of these alternatives resulted in that the second alternative is most economic and feasible. So as to stably cope with the newly estimated PMF by meeting all the current functions of the multipurpose dam, a detailed study of an additional spillway tunnel has to be followed.

• Journal of Korea Water Resources Association
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• v.53 no.2
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• pp.97-105
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• 2020

Recently, Artificial Neural Network receives attention as a data prediction method. Among these, a Long Shot-term Memory (LSTM) model specialized for time-series data prediction was utilized as a prediction method of hydrological time series data. In this study, the LSTM model was constructed utilizing deep running open source library TensorFlow which provided by Google, to predict inflows of multipurpose dams. We predicted the inflow of the Yongdam Multipurpose Dam which is located in the upper stream of the Geumgang. The hourly flow data of Yongdam Dam from 2006 to 2018 provided by WAMIS was used as the analysis data. Predictive analysis was performed under various of variable condition in order to compare and analyze the prediction accuracy according to four learning parameters of the LSTM model. Root mean square error (RMSE), Mean absolute error (MAE) and Volume error (VE) were calculated and evaluated its accuracy through comparing the predicted and observed inflows. We found that all the models had lower accuracy at high inflow rate and hourly precipitation data (2006~2018) of Yongdam Dam utilized as additional input variables to solve this problem. When the data of rainfall and inflow were utilized together, it was found that the accuracy of the prediction for the high flow rate is improved.

• Journal of Environmental Science International
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• v.13 no.3
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• pp.197-204
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• 2004

In this study analyzed the reliability indices against the water supply ability of Andong dam. The water supply analysis of Andong dam used the HEC-5 model. So Andong dam simulated planed water-supply capacity of Andong dam as increase and decrease +5% ～ -5% of water supply quantity. Water-supply capacity of Andong dam estimated, deficit occurrence, deficit quantity, deficit period. As the results estimated reliability(occurrence based, time based, quantity based) and resiliency vulnerability and with water supply capacity evaluation indices of Andong dam. Also reliability(occurrence based, time based, quantity based), resiliency, vulnerability and resiliency indices are estimated to evaluated the performance of water supply on Andong dam, and their relationships are evaluated.

• Korean Journal of Construction Engineering and Management
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• v.8 no.3
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• pp.168-176
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• 2007

This study aims to provide useful information when making a decision for the environmental and economic efficiency assessment of infrastructure, based on Life Cycle Assessment(LCA). It estimates environmental cost on environmental pollutants that are possible to happen by locations and by types of emergency spillway for korean multipurpose dam, which is selected as a study case. For this purpose, this study examines the theories of LCA and Contingent Valuation Method(CVM) and suggests an analysis model of environmental cost. To apply the suggested analysis model of environmental cost for infrastructure to the case study of emergency spillway at the multipurpose dam, this study calculates environmental load on environmental pollutants that generate during life cycle, converts it to a cost to predict environmental cost, evaluates environmental economy of emergency spillway by the estimated result, and draws the optimum alternative that is environmental-friendly and economic.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.3
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• pp.549-559
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• 2017

The complementary relationship hypothesis for areal evapotranspirations was validated in the regional-scale area of multipurpose dam basins in Korea and the long-term water balances were indirectly identified. Annual actual evapotranspiration ($ET_A$) was assumed the difference between total annual precipitation and total annual inflow and the available moisture was assumed the total precipitation. The seasonally varying pan coefficient (kp) is estimated as the ratio of the $ET_{pan}$ and the evapotranspiration calculated by FAO Penman-Monteith equation ($ET_{PM}$). The complementary relationships using ground observation data of $ET_P$ and $ET_A$ in the multipurpose dam basins follow generally the typical pattern that $ET_P$ and $ET_A$ is complementary and converges to equivalent evapotranspiration ($ET_W$) under the extreme wet environment. However, $ET_A$ of Juam dam was estimated relatively greater than other basins and exceeds even $ET_P$ at certain range with high moisture availability, which can be understood as the results of possible over-estimation of precipitation or under-estimation of dam inflow. It is expected that the use of evapotranspiration complementary relationship for validating hydrological water balances will contribute to controlling uncertainties in estimating dam inflows during flood season in particular.

• Journal of Korea Water Resources Association
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• v.38 no.3 s.152
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• pp.179-188
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• 2005

This study on the HwaBuk Multipurpose Dam showed that two- and three- dimensional numerical model experiments, as well as hydraulic model experiments, can be useful analysis tools for engineers. A commercially available RMA2, which solves the shallow water equations, and FLOW-3D, which solves the Reynolds averaged Navier-Stokes equations, were used to simulate the hydraulic model setup. Numerical simulation results on the following were compared with the hydraulic model results: the flow in the reservoir basin and the approaching channel; the discharge in the overflow weir; the water surface profiles in the rollway, chute, and stilling basin; and the pressure distributions in the rollway. It was shown that there is a reasonably good agreement between the numerical model and the hydraulic model for the most of computations. There were, however, some differences between the numerical simulation results and hydraulic model results for the hydraulic jump in the stilling basin because of air entrainment effect.

• Journal of Environmental Impact Assessment
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• v.8 no.2
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• pp.45-51
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• 1999

Emergy concept was used to evaluate the contributions of a dam construction to the real wealth of our economy. A dam that is proposed as a multi-purpose dam was used to illustrate emergy evaluation methodology. Models for emergy evaluation were constructed with energy systems language, a symbolic modeling language which presents network properties of systems holistically. Water supply was the most important contribution in terms of emergy, which reflects that the dam is proposed for stable water supply to a local region. Generation of electricity was the second in emergy benefits of the dam. Emergy costs were more evenly distributed among the costs which would occur as a result of the dam construction. Emergy yield ratio was 1.30 if sediments are not included, and 1.15 if sediments are included, which results in net yield in both cases. The ratio would, however, fall below 1.0 if rare species within the system boundary are lost as a result of the dam construction because of the high emergy value included in biotic species, which means that emergy costs will be greater than emergy benefits. This study illustrated a new methodology in environmental impact assessment to better manage our environments in an age of diminishing resources.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.503-506
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• 2003

The DAWAST model was originally developed to consider daily variation in the unsaturated soil water storage and it is a conceptual lumped model. Return flows from agricultural, domestic and industrial water were included to the original result of model simulation to calibrate model parameter. Daily inflow to the Daechung multipurpose dam was applied to verify the DAWAST model considered return flows. Simulation results were comparable to the inflows of dam operation reasonably.