• Journal of the Korean GEO-environmental Society
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• v.20 no.1
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• pp.19-25
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• 2019

In this present study, to evaluate the applicability of the monitoring system of the entire reservoir dam facility using the wireless sensor network system and a section representative of the domestic reservoir dam was selected as the test bed site and to operated a system that can evaluate the condition of the facility at the real time with monitoring. In order to set up a wireless sensor network system, the system assessment of present state was carried out for confirmation the risk factors and the limit values of the risk factors in limit state were calculated. The type and position of the sensor to be measured in the field were determined by setting the measurement items suitable for the hazardous area and the risk factor. In this paper, we evaluated the feasibility of the system by monitoring and constructing a wireless sensor network system in a field for a fill dam that can represent a domestic reservoir dam. Applicability evaluation was verified by comparing directly with the measurement of partial concentration method which is the measurement management technology of the dam.

• Journal of Korea Water Resources Association
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• v.51 no.1
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• pp.61-70
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• 2018

This study examined how to determine the optimal sediment level in dam reservoir for efficient plan and operation of dam. Currently, Korea is applying a horizontally accumulated method for sediment level estimation for the safety design of dam and so the method estimated relatively higher level than others. However, the sediment level of dam reservoir should be accurately estimated because it is an important factor in assessing life cycle of a dam. The sediment level in dam reservoir can be determined by SED-2D model linked with RMA-2, horizontally accumulated method, area increment method, and empirical area reduction method. The estimated sediment level from each method was compared with the observed sediment level measured in 2007 in Imha dam reservoir, Korea and then the optimal method was determined. Also, the future sediment level was predicted by each method for the future trend analysis of sediment level. As the results, the most accurate sediment level was estimated by the empirical area reduction method and the future trend of sediment level variation followed the past trend. Therefore, we have found that the empirical area reduction method is a proper one for more accurate estimation of sediment level and it can be validated by the results from a numerical model of SED-2D linked with RMA-2 model.

• Journal of Korea Water Resources Association
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• v.34 no.6
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• pp.617-625
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• 2001

Peace dam constructed against the water attack had stopped in the first step, linked with Hwacheon dam through bypass tunnels and had an effect of flood surcharging in its pocket on Hwacheon dam downstream. To study the utility of Peace dam, the flood control effects of Peace dam and the restricted water level (RWL) in Hwacheon dam were reviewed and identified with operating Hwacheon dam system. Analysing the results the ideas of expanding the usability of the water resources in Hwacheon dam system were suggested. To do that, the criteria and the model of reservoir operation were established frist and the optimization of the operation have done. Based on the results the performance of the optimization was evaluated as an reference coefficient with relative value of the registered data to the optimized. And examining several alternatives for the RWL in Hwacheon reservoir operation made more feasible RWL suggested. And its economic benefit was also reckoned.

• Earthquakes and Structures
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• v.6 no.3
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• pp.251-266
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• 2014

Dynamic analyses for a suite of ground of motions were conducted on concrete gravity dam sections to examine the earthquake induced stresses and effective damping. For this purpose, frequency domain methods that rigorously incorporate dam-reservoir-foundation interaction and time domain methods with approximate hydrodynamic foundation interaction effects were employed. The maximum principal tensile stresses and their distribution at the dam base, which are important parameters for concrete dam design, were obtained using the frequency domain approach. Prediction equations were proposed for these stresses and their distribution at the dam base. Comparisons of the stress results obtained using frequency and time domain methods revealed that the dam height and ratio of modulus of elasticity of foundation rock to concrete are significant parameters that may influence earthquake induced stresses. A new effective damping prediction equation was proposed in order to estimate earthquake stresses accurately with the approximate time domain approach.

• Geomechanics and Engineering
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• v.17 no.2
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• pp.207-214
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• 2019

Dams have a great importance on energy and irrigation. Dams must be evaluated statically and dynamically even after construction. For this purpose, Torul dam built between years 2000 and 2007 Harsit River in Gümüşhane province, Turkey, is selected as an application. The Torul dam has 137 m height and 322 GWh annual energy production capacity. Torul dam is a kind of concrete face rock fill dam (CFRD). In this study, static and pseudo seismic stability of Torul dam was investigated using finite element method. Torul dam model is constituted by numerical stress analysis named Phase2 which is based on finite element method. The dam was examined under 11 different water filling levels. Thirteenth stage of the numerical model is corresponding full reservoir condition which water filled up under crest line. Besides, pseudo static coefficients for dynamic condition applied to the dam in fourteenth stage of the model. Stability assessment of the Torul dam has been discussed according to the displacement throughout the dam body. For static and pseudo seismic cases, the displacements in the dam body have been compared. The total displacements of the dam according to its the empty state increase dramatically at the height of the water level of about 70 m and above. Compared to the pseudo-seismic analysis, the displacement of dam at the full reservoir condition is approximately two times as high as static analysis.

• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.4
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• pp.1-8
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• 2016

In 2008, 17, 596 dams and reservoirs are scattered across South Korea, and 17, 505 of them (99.5 %) are used for agriculture and 99.3 % are fill dam types. This study aimed to review literature related to the precise safety diagnosis system for agricultural reservoirs established by Korea Rural Community Corporation (KRCC) and analyze problems of its evaluation method. And then, it proposed ways to improve the system including a modified diagnosis system, which was applied to pilot districts in order to verify the utility. For assessment model development of agricultural reservoir, we reviewed status of precision safety inspections systems of agricultural reservoir. There are many problems such as assess agricultural reservoir not by sheet which used in fill dam but by block which used in concrete dam construction and diversion tunnel which main element in reservoir levee is treated as water intake facility. For considering diversion tunnel in reservoir levee, previous precision safety inspection systems which summed in separated phenomenon, separated element, separated site, separated facility was change to new systems which summed in site, phenomenon, element, and facility. Compared results of previous inspection system calculated total assessment index (Ec) with new system calculated total assessment index (Ec) are not show statistical difference.

• 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.

• Journal of Korea Water Resources Association
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• v.44 no.5
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• pp.407-416
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• 2011

This study expressed the reservoir's storage-discharge relation as a non-linear reservoir model and theoretically quantified the reservoir storage effect. Among those non-linear functions like exponential function, logarithmic function and power function considered, the exponential function of the storage-discharge relation was found to be the most valid. The non-linear reservoir model proposed was applied to the Chungju Dam and the Soyang River Dam, whose storage effects during flood were estimated to be about 23 hours and 43 hours, respectively. This result indicates that the Choongju Dam, even though its size and total storage volume are similar to those of the Soyang River Dam, does not achieve enough storage effect as its basin size and the inflow amount are much larger.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.209-209
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• 2022

Reservoirs play a key role in the carbon cycle between terrestrial and marine systems and are pathways that release greenhouse gases(GHGs), CO₂, CH₄, and N₂O, into the atmosphere by decomposing organic matters. Developed countries have been actively conducting research on carbon emission assessment of dam reservoirs for over 10 years under the leadership of UNESCO/IHA, but associated research is very rare in Korea. In particular, the GHGs footprint evaluation, which calculates the change in net carbon emission considering the watershed environment between pre- and post- impoundment, is very important in evaluating the carbon emission of hydroelectric dams. The objective of this study was to estimate the GHG emissions and footprints in Daecheong Reservoir using the G-res Tool, an online platform developed by UNESCO/IHA. The G-res Tool estimates CO₂ and CH₄ emissions in consideration of diverse pathway fluxes of GHGs from the reservoir and characterizes changes in GHG fluxes over 100 years based on the expected lifetime of the dam. The input required to use the G-res Tool include data related to watersheds, reservoirs, and dams, and most were collected through the government's public portal. As a result of the study, the GHG footprint of Daecheong Reservoir was estimated to be 93 gCO₂eq/m²/yr, which is similar to that of other reservoirs around the world in the same climate zone. After impoundment, the CH₄ diffusion emission from the reservoir was 73 gCO₂eq/m²/yr, also similar to those of the overseas reservoirs, but the CH₄ bubbling emission, degassing emission, and CO₂ diffusion emissions were 44, 34, 252 gCO₂eq/m²/yr, respectively, showing a rather high tendency. Since the dam reservoir carbon footprint evaluation is essential for the Clean Development Mechanism evaluation of hydroelectric power generation, continuous research is needed in the future. In particular, experimental studies that can replace the emission factors obtained from the overseas dam reservoirs currently used in the G-res Tool should be promoted.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.6
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• pp.63-73
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• 2010

This study is to develop a downstream flood damage prediction model for efficient confrontation in case of extreme and flash flood by future probable small agricultural dam break situation. For a Changri reservoir (0.419 million $m^3$) located in Yongin city of Gyeonggi province, a dam break scenario was prepared. With the probable maximum flood (PMF) condition calculated from the probable maximum precipitation (PMP), the flood condition by dam break was generated by using the HEC-HMS (Hydrologic Engineering Center - Hydrologic Modeling System) model. The flood propagation to the 1.12 km section of Hwagok downstream was simulated using HEC-RAS (Hydrologic Engineering Center - River Analysis System) model. The flood damaged areas were generated by overtopping from the levees and the boundaries were extracted for flood damage prediction, and the degree of flood damage was evaluated using IDEM (Inundation Damage Estimation Method) by modifying MD-FDA (Multi-Dimensional Flood Damage Analysis) and regression analysis simple method. The result of flood analysis by dam-break was predicted to occurred flood depth of 0.4m in interior floodplain by overtopping under PMF scenario, and maximum flood depth was predicted up to 1.1 m. Moreover, for the downstream of the Changri reservoir, the total amount of the maximum flood damage by dam-break was calculated nearly 1.2 billion won by IDEM.