• Journal of Korea Water Resources Association
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• v.48 no.7
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• pp.523-533
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• 2015

In this study, the effectiveness of overflow improvement of weir was tested by conducting hydraulic experiments at the designated spot for installment of side weir under the condition of installment of hydraulic structures such as small reservoir in mainstream. The height of the reservoir was set up as a third of that of the weir, accordingly the rate of the height of the weir and the distance of the reservoir from the weir($B_h/L_b$) were 0.05, 0.025, 0.0167 each. As a result, overflows per unit width increased by 8.1%, 5.4% and 3.9% perspectively. A new discharge coefficient that adds $B_h/L_b$ as parameter to the existing discharge coefficient of trapezoidal broad crested side weir was suggested and the application of the new formula of discharge coefficient by comparing measured overflow with calculated overflow was identified.

• Journal of Environmental Impact Assessment
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• v.19 no.2
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• pp.153-168
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• 2010

The objectives of this study are to analyze flow characteristics for a side weir, which is an inlet structure for flow discharge reduction in the main channel through 3 dimensional numerical analysis and to understand the efficiency of the overflow effect at the side weir. In this study over 40 simulations using FLOW-3D, a computational fluid dynamics program were conducted, and the results were analyzed to find the influence of the flow hydraulics, geometry, channel and weir shapes on the coefficient. It is especially considered the relatively high stage in downstream that may cause flow within channel to be backed up along the channel. Additionally by setting up the scale of simulations much larger than the existing test equipment designed by other researchers, it is intended to analyze more accurate hydraulic behavior along with the realistic hydraulic features such as structures and volumes of flow. The results show that for design with subcritical flow only if the Froude number of upstream is sustained below 0.5 and the length of weir is 33-100% of the width of channel, it is expected to improve the efficiency of the overflow over a side weir.

• Journal of Wetlands Research
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• v.19 no.2
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• pp.181-192
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• 2017

Analysis using a numerical model is important to understand the sediment transport mechanism associated with erosion and sedimentation near weirs and other hydraulic structures within riverine systems. The local riverbed change near a hydraulic structure (Gangjeong-Goryong multi-function weir in the Nakdong river) was analyzed in order to examine the effect of hydraulic structures on local bed change. A 2D numerical model (CCHE-2D) was employed to simulate the sedimentation and erosion over a reach (25 km) including the weir. For the calibration and verification of the model, rainfall data from a real event (Typoon 'Ewiniar' in 2006) were used for flow and stage simulation. And the simulated results show a good agreement with the observed data for the whole domain. From the result, it was found that the installation and operation of the weir could aggravate bed changes by typhoon between movable weirs, and which resulted in redistribution of sediment.

• 한국생태학회:학술대회논문집
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• 1999.05a
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• pp.77.1-77.1
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• 1999

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2001.08a
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• pp.37-47
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• 2001

No Abstract, See Full-text

• Ecology and Resilient Infrastructure
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• v.7 no.4
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• pp.353-365
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• 2020

In this study, the characteristics of bed elevation changes of the Nakdong River when weir gates are opened were analyzed using the Hydrologic Engineering Center-River Analysis System (HEC-RAS). The study area was 292.37 km downstream of the Gudam Bridge to the Nakdong estuary of the Nakdong River. The HEC-RAS program, which is a 1D numerical analysis model, was used to simulate bed elevation changes. Simulations were conducted under two scenarios from 2017 to 2019. Scenarios 1 and 2 were devised under the conditions of a fully opened gate and during gate installation, respectively. Results confirmed that, under the conditions of Scenario 1, deposition occurred in most sections from the Hapcheon-Changnyeong weir to the Changnyeong-Haman weir (a distance of approximately 40 km). In addition, it was predicted that the flow that included sediments in the main stream of the Nakdong River was not interrupted by the weir structure and regularly produced changes in the river bed.

• Journal of Korea Water Resources Association
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• v.51 no.7
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• pp.555-564
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• 2018

The detention reservoir is a hydraulic structure that constructs a levee on the inland of river and sets up side weir in a section of the levee, and this facility stores a part of the flood volume in case of a flood event over a certain scale. In order to optimize the operation of detention reservoir, it is necessary to review the linkage with existing facilities in the river. In this study, the effect of water level reduction and the flow distribution was analyzed according to the location of the side weir in the detention reservoir considering the run-of-the-river gate. Two radial gates were installed in the experimental channel, and the water level in channel and the overflow of weir were measured by moving the location of the side weir upstream from the gate. As a results of experiment, it was confirmed that the water level reduction is more remarkable as the location of the side weir was closer to the gate, and the effect of flow distribution is not greatly changed. When two or more side weirs were operated, it is confirmed that the sufficient storage space was secured and the water level reduction effect with the location of the side weir is not large. In addition, the water level reduction rate according to the location of the side weir was estimated by empirical formula and it is provided as basic data that can be used in the planning of the detention reservoir.

• Journal of Wetlands Research
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• v.15 no.4
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• pp.573-583
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• 2013

Construction of large-scale structures such as dams would be suggested actively to cope with change of flood characteristics caused by climate change. However, due to environmental, economic and political issues, dams are not ideally constructed. Thus flood damage reduction planning projects would get started including washland or detention pond for sharing the flood in basin. The washland made artificially by human being is an area of floodplain surrounded by bank to be intentionally inundated by overflowing through overflow structure adjacent to main channel during flood season. Flood reduction capacity at just downstream of each washland could be affected by type, length, and crest elevation of overflow structure in addition to shape of design hydrograph, storage volume of washland, etc.. In this study flood reduction effects of washland are estimated for overflow weir type and gate type to compare the results of flood reduction respectively subjected to given hydrograph in sample site, the Cheongmicheon stream. It has been shown that even if gate type at overflow structure could yield more flood reduction than overflow weir type, economic aspect such as initial cost, operation cost and maintenance cost should be considered to select the type of overflow structure because flood reduction rate by gate type could not be significant value from engineering point of view.

• Journal of Korea Water Resources Association
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• v.46 no.7
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• pp.707-717
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• 2013

Channel-bed of erosion and sedimentation, where eroded bed and bank materials re-deposit through the action of flow, is a natural phenomenon in alluvial systems. Analysis using a numerical model is important to understand the sediment transport mechanism associated with erosion and sedimentation near weirs and other hydraulic structures within riverine systems. The local riverbed change near a hydraulic structure (Changnyong-Haman multi-function weir in Nakdong river) has been analyzed in order to examine the effect of hydraulic structure on local bed change. A 2D numerical model (CCHE-2D) has been implemented to simulate the sedimentation and erosion over a reach (10 km) including the weir. For the calibration and verification of the model, the rainfall data from a real event (Typoon 'Maemi' in 2003) has been used for flow and stage simulation. And the simulated results show a good agreement with the observed data for whole domain. From the result, it was found that the installation and operation of weir can aggravate the local bed change caused from the flow field change and resulting redistribution of sediment.

• Korean Journal of Heritage: History & Science
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• v.55 no.3
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• pp.132-150
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• 2022

Designated as a national intangible cultural asset, the fish weir is a traditional fishing method and was a leading fishing tool in Korean coastal fishery. As the littoral sea area fishing vessel fishery developed since the 1970s, traditional fishing methods including fish weirs began to decline. The fish weir has been passed down in the form of tools such as fish weirs, stone weirs, and bamboo weirs. In Namhae-gun and Sacheon City in Gyeongsangnam-do, anchovies are caught using bamboo weirs. A basic bamboo weir consists of a fish trap(balgong), a space where fish gather together, and a V- or U-shaped wooden fence(halgaji) that helps fish come inside the fish trap. Its fishing method is to catch fish that have come to the coast during high tide alongside those are stuck inside fish traps(balgong) with nets or scoop nets. This paper examined the process of passing down traditional fishing methods through a comparative analysis of the bamboo weir structures and fishing methods in the Namhae and Sacheon regions. First, the historical process of assembling the current bamboo weir structure was analyzed. The bamboo weir, a fishing tool, appears to have combined the features of past weirs and fish weirs based on the Jijok Strait and Samcheonpo Strait. Next, this paper examined the structure and fishing method of the two types of bamboo weirs made with a circular or square fish trap(balgong) where fish gather. Through this analysis, this study examined the lives of fishermen who have adapted to their natural environment and actively utilized obtainable resources(materials), and then changed the traditional fishing method of bamboo weirs and developed them into an appropriate technology. Lastly, a new value attributed to anchovies caught using bamboo weirs was analyzed. This new value extracted from better bamboo weir anchovies works as a mechanism to uphold the tradition of anchovy-catching bamboo-weir fishing, which produces a smaller amount of anchovies compared to other methods of anchovy fishing. In this way, bamboo weir fishing has been passed down as a result of its differentiated aspect of producing better anchovies than those produced with other fishing methods, as well as the historical aspect of it being a traditional fishing method.