• Journal of Korea Water Resources Association
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• v.31 no.6
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• pp.727-739
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• 1998

The main objectives o reservoir optimal operation can be described as follows : maximization of the benefits through optimal allocation of the limited water resources for various purpose; minimization of t도 costs by the flood damage in potential damaging regions and risk of dam failure, etc. through safe drainage of a bulky volume of excessive water by a proper reservoir operation. Reviewing the past research works related to reservoir operation, we can find that the study on the matter of the former has been extensively carried out in last decades rather than the matter of the latter. This study is focused on developing a methodology of optimal reservoir operation for flood control, and a case study is performed on the Chungju multipurpose reservoir in Korea. The final goal of the study is to establish a reservoir optimal operation system which can search optimal policy to compromise two conflicting objectives: downstream flood damage and dam safety-upstream flood damage. In order to reach the final goal of the study, the following items were studied : (1)validation of hydrological data using HYMOS: (2)establishment of a downstream flood routing model coupling a rainfall-runoff model and SOBEK system for 1-D hydrodynamic flood routing; (3)replication of a flood damage estimation model by a neural network; (4)development of an integrated reservoir optimization module for an optimal operation policy.

• Journal of Korea Water Resources Association
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• v.30 no.6
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• pp.679-690
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• 1997

The risk assessment model for hydrlolgic safety analysis of dam and levee in developed by using Monte-Carlo and AFOSM (Advanced First-Order Second-Moment) method. The fault tree analysis and four phases approach are presented for the safety eveluation of risk of dam and levee. The risk model consists of rainfall-runoff analysis, reservoir routing and channel routing considering the variations in the model parameter. For the rainfall-runoff analysis, KRRL method is adopted with 200-year precipitation and PMP (Probable Maximum Precipitation). Reservoir routing is performed by fourth order Runge-Kutta method and channel routing by standard step method. The suggested model will contribute to safety evaluation of dam and levee and their rehabilitation decision problem.

• Journal of Korea Water Resources Association
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• v.40 no.1 s.174
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• pp.1-10
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• 2007

Reallocation procedure of multipurpose reservoir storage capacity between flood control and conservation is presented as an alternative to secure more water resources. Storage reallocation is an adaptive management mechanism for converting existing normal pool level of reservoirs to more beneficial uses without requirement for physical alteration. This study is intended to develop a reservoir storage reallocation methodology that allows increased water supply storage without minimizing adverse impacts on flood control. The methodology consists of flood control reservoir simulation for inflows with various return periods, flow routing from reservoir to a potential damage site, analyzing river carrying capacity, and reservoir yields estimation for reallocated storages. For the flood control model, a simulation model called Rigid ROM(Reservoir Operation Method) and HEC-5 are used. The approach is illustrated by applying it to two reservoirs system in Geum River basin. Especially with and without new project conditions are considered to analyze trade-offs between competing objectives.

• Journal of Korea Water Resources Association
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• v.37 no.1
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• pp.43-54
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• 2004

The objective of this study is to propose reservoir operation method in relation to the suspended sediment concentration due to rainstorms. Present analysis is made for the Tamjin reservoir which is under construction. For the hydrologic computations the Huff rainfall distribution, Clark unit hydrograph method and Puls reservoir routing method are used. The variation of suspended sediment concentration is calculated by 2-dimensional RMA-4 model. As a result of this study, the possible intake time from the reservoir under low frequency flood is estimated and the rainfall-ret urn period - possible intake time relationship is established, which is very important in maintaining the water quality standard when supplying water from the reservoir for different utilizationurn period- possible intake time relationship is established, which is very important in maintaining the water quality standard when supplying water from the reservoir for different utilizations.

• Journal of Korea Water Resources Association
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• v.51 no.4
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• pp.371-381
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• 2018

Domestic agricultural reservoir dam facilities are difficult to manage water resources because of the in summer rainfall increase due to aging and climate change, it is expected that the dam risk will be large due to the overflow. In this study, author selected study basin in order to evaluate hydrological safety of agricultural reservoir dam facilities. And calculated the probable rainfall, Present PMP, Future PMP considering climate change. Also, author carried quantitative analysis out for increasing rainfall due to climate change, analyze freeboard assessment of agricultural reservoir by calculate flood discharge, reservoir flood routing according to rainfall scenarios. As a result of evaluate hydrological safety of agricultural reservoir dam facilities using Future PMP considering climate change, Gosam, Kumkwang, Miho, Cheongcheon reservoir had the Highest Water Level over the design flood level, it is analyzed that it would be vulnerable to overflow risk.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.2B
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• pp.93-101
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• 2012

HEC-ResSim, reservoir operation model, is applied to Seomjin river dam in order to establish a rational method for water supply and flood control by dam operation. In order to minimize downstream flood damage for Seomjin river basin and adjacent regions, reservoir routing is applied to several frequency flood events within the framework of rainy seasonal operation rule and then the characteristics change of hydrological behavior for the downstream of study area is investigated in depth. Its quantitative efficiency and estimation method is evaluated on the basis of the adjustment scheme of conservation water surface elevation for flood control and water secure; reservoir routing considering preliminary release and variable restricted water level; and its effect to water supply; and downstream flood-duration analysis.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.299-302
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• 2003

This study aims to apply and compare flood routing methods for irrigation reservoirs. In this research, three methods, which are the storage indication method(SIM), the mass curve method(MCM), the frog method(FM) were adopted and applied to two storm events of July $9{\sim}10\;and\;22{\sim}23$ of Donghwa-dam and its watershed located on Jangsoo-gun, Chunnam province. As the application results MCM showed the highest value at peak overflow and goodness-of-fit to the observed value, although the others also had similar value with the observed one. In analyzing lag time of peak between inflow and overflow MCM and SIM showed 7 hours, while FM showed 6 hours for the first storm event, and all three methods showed 3 hours for the second event.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.51-56
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• 1999

An object-orient watershed runoff model was formulated using the SCS curve number method and routing routines. The four objects included in the model were rainfall , hydrologic unit, reservoir, and channel. Each object considers the data and simulation method to depict the runoff processes. the details of which were presented and discusses in the paper. The resulting model was applied to the HS #3 watershed of the Balan Watershed Project, which is 412.5 ha in size and relatively steep in landscape. The simulated runoff hydrographs from the model were close to the observed data.

• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.2
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• pp.269-278
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• 2004

In this study, hydraulic and hydrologic safety of an existing dam with morning glory spillway was evaluated and the problems were derived in order to control extreme floods efficiently. For design flood(520cms and EL. 170.3m), the spillway was turned out to have no problem for discharge and negative pressure in vertical transition. However, the critical point for discharge starts with EL. 170.7m which transits weir flow condition to orifice flow condition and there may be negative pressure in weir crest. While maximum water level can not be greater than EL. 170.5m including freeboard according to the dam design criteria, the maximum water level based on reservoir routing was turned out to be EL. 172.46m, and fundamental measures should be requested and planned.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.722-725
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• 2007

Geum River Estuary Barrage is very important for the irrigation, municipal and industrial uses in the cities of Gunsan, Iksan and Jeonju. The Geum River Control Office has a flood forecasting system; however, the current system does not consider the backwater effects. As a result, it is very difficult to give correct flood information, and it is difficult to accurately assess the water resource supply and saltwater invasion into freshwater, as frequently occurs due to over-discharge during floods. In this study, we investigate the flood forecasting system for the Geum River reach influenced by the estuary barrage. The current system cannot consider the backwater effect because the estuary barrage blocks the end of the river. We calculated the discharge from the tide lock and evaluated the inside water level of the estuary barrage during floods. The results show that the calculation agrees well with the observed data at the river stage stations in the Geum River. The results also show that this program is a reasonable substitute for the current system.