• 상하수도학회지
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• 제21권3호
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• pp.265-272
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• 2007

This study uses the SWAT model to analyze the characteristics of long-term runoff at the Ssang-cheon Basin located in the city of Sokcho, which is located in the province of Gangwon. The study considers the effect of snow packing and snow melting in a runoff simulation. In this simulation, the study examines the need to introduce a snow pack and snow melt model to evaluate the water resources of the mountainous region of the Gangwon province. The findings of this study indicate that the runoff hydrograph that was produced approximates the true measured flow when the effect of the snow pack and snow melt are considered, compared to when they are not factored in. The analysis of the flow duration curve indicates that the stream flow largely increases when the effect of the snow pack and snow melt are considered. The wet stream flow was shown to increase by nearly 3% due to the melting effect, while the normal stream flow, low stream flow and drought stream flow were shown to increase by slightly more than 10%. Specifically, it was found that as the stream flow decreases, the effect of the snow pack and snow melt on the stream flow increases.

• 환경영향평가
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• 제14권1호
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• pp.37-46
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• 2005

In this study, field surveys were performed for 12 stations in main stream of Hongjechun and 3 stations in 2 tributaries, respectively, in order to find out dried reaches of the stream, and to examine the water quality of the stream, and to suggest methods to improve the stream concerned into eco-stream. In the results of water quality in stream, however distinct difference for seasonal variation of the water quality was not found, the water quality of winter was relatively better than that of other seasons. Annual mean concentration of BOD was 6.5mg/L in the upper reach, 11.8mg/L in the middle reach, 15.3mg/L in the lower reach of main stream, and total mean was 12.5mg/L, while the BOD concentration was 3.6mg/L in the upper reach, and was 9.6mg/L in the low reach of Gukichun, the tributary. Based on flow examination, the level of water depth was so low and the flow can not be traveled downstream in the reach between ST-9 and ST-10 for low water season, whereas it was observed that the flow was traveling except the dry season even the water level was lower than that of adjacent stations.

• 한국조경학회지
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• 제28권1호
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• pp.83-91
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• 2000

This study was carried out to develop the close-to nature construction technology for the stream which has been improved just for the flood control with artificially straightened and concrete covered, losing the various functions of the stream such as wild-life habitat, polluted water purification and waterscape. Jungpyung stream in youngin City, Kyunggi Province was selected as a case study site. The results were as follows; 1. Existing stream improvement planning could accept the close-to-nature techniques of the low-flow revetment, keeping the capability of flood control and water use. 2. The low-flow revetment was planned and executed to the bottom of the stream without damaging the existing bank, and the slope of the low-flow revetment was adjusted as 1:1.2∼1.5. Consequently it would not disturb the water flow when the flood occurred and it would keep the constant water flow even at the drought with providing a stable ecosystem and water purification. 3. Low-flow revetement was planted with Salix species and perennials naturally, and it would be a precious biotope for the diverse floras and faunas. 4. Some furnitures such as stepping stone bridge, wooden bridge and step were installed to the suitable locations for the convenience of users, and it will be ot only the sound stream environment but also easy access to the waterscape. 5. This case study site will be monitored for 3 years systematically after the construction was finished in September, 1999 to get the exact results for the scientific approvement

• 물과 미래
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• 제14권1호
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• pp.31-37
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• 1981

금강수계의 미계획지점에 대한 갈수량빈도곡선의 합성은 하천형태학적 인자인 유역면적, 유역의 기복량, 하천의 연장 및 미국연방주환경국의 하천수질기준인 10년 7월 평균 갈수량을 이용한 상관관계를 분석함으로서 가능하였다.

• 한국물환경학회지
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• 제31권1호
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• pp.35-41
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• 2015

This study focuses on whether a physical habitat model, River2D, is useful to assess and design stream restoration. To achieve the aim, the habitat suitability for Zacco Platypus was analyzed using River2D at midstream of the Anyang-Cheon through modifying the low flow channel and changing the flow discharge. The River2D simulation results show that the inhabited environment for Zacco Platypus is improved by increasing the sinuosity of the low flow channel, and vice versa. Also the inhabited environment for Zacco Platypus gets worse when there is no additional flow for maintenance water supply at the stream flowing through cities. In this respect, the physical habitat simulation study based on the River2D model is useful because it provides a practical guidance in designing stream restoration.

• 한국농공학회논문집
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• 제49권6호
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• pp.11-20
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• 2007

In order to make the way to determine the instream flow more practically, we have investigated many case studies and reviewed reports and papers. To validate instream flow level suggested by the case studies, DAWAST and HEC-RAS model were applied to the Gap-stream watershed in Daejeon city. Flow-duration analysis was performed both with the stream flow data gauged in the Indong, Boksu, and Hoeduck stations, and with the stream flow data estimated by the DAWAST model and the specific discharge method. Instream flow was determined among the flow-duration analysis, DAWAST, HEC-RAS model and mass balance approach. It was satisfied with various factors such as target water quality, water depth for eco-system and resorts, water surface width, flow velocity for landscape in dry season. The study suggested that the mean low flow could be replaced into the instream flow for the preliminary study because the instream flow considering ecosystem, landscape, water-friendly environment and water quality was generally close to the mean low flow.

• 한국환경보건학회지
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• 제38권5호
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• pp.438-447
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• 2012

Objective: The objective of this study was to suggest a method through which load duration curve was used to assess the achievement of water quality targets in accordance with the criteria for pollutant load depending on flow rate variation. Methods: The stage-discharge curve and flow duration curve of Jungnang Stream were deduced. Using water quality targets and measurement of the stream, the flow duration curve was also drawn. Based on these, the feasibility of achievement of water quality targets in respect to flow rate was assessed. Results: In terms of the load duration curve of the stream, it was observed that excess of criteria for concentrations of $BOD_5$, $COD_{Mn}$ and SS frequently occurred. On the other hand, when the flow rate was low, the concentrations of T-N and T-P exceeded the criteria. Conclusions: Through the load duration curve, the overall water quality of Jungnang Stream was understood. When the flow rate is high, management of point source of $BOD_5$, $COD_{Mn}$ and SS is needed to achieve water quality targets for Jungnang Stream. On the other hand, when the flow rate is low, the management of non-point source T-N and T-P is necessary to attain the water quality goal.

• 한국환경보건학회지
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• 제9권1호
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• pp.1-13
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• 1983

This study was carried out to investigate nitrification in the main stream of the Naktong river for two times, 12-13 August and 23-26 September 1982. The results of this study were as follows : 1. The increase of nitrogen concentration was due to inflow of Geumho river, which was polluted by the municipal and industrial wastewater of Daegu city. 2. The rate constant of ammonia calculated for three reaches was high according to the stream flow and was eminently low in the reach from Goroung to Gangjung. (0.068-0.116 $day^{-1}$). This phenomena might be attributed to the sublethal or even lethal effect upon aquatic life by relatively low DO concentration and high heavy metal concentration. 3. DO consumption rate by nitrification was highest for the reach from Goroung to Daeam where was affected by Geumho river. (56.7-147.8%). This phenomena might be attributed to low DO concentration and high nitrogen concentration. Especially, the less stream flow was, the higher DO consumption was. And so, nitrification in the station where is low DO concentration, especially under the low flow condition, might cause more serious water quality management problem. Therefore, for the purpose of effective conservation of water quality in the Naktong river, it was suggested that We have more concern about the nitrogen compound, and more study on the nitrification phenomena.

• 한국안전학회지
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• 제27권5호
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• pp.35-41
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• 2012

The Numerical simulation was performed on the flow field around the two-dimensional rectangular bluff body in order to complement the previous experimental results of the bluff body stabilized flames [1]. For both fuel ejection configurations against an oxidizer stream, the flame stability was affected mainly by vortex structure and mixing field near bluff body. FDS(Fire Dynamic Simulator) based on the LES(Large Eddy Simulation) was employed to clarify the isothermal mixing characteristic and wake flow pattern around bluff body. The air used atmosphere and the fuel used methane. The result of counter flow configuration shows that the flow field depends on air velocity but the mixing field is influenced on the fuel velocity. At low fuel velocity the fuel mole fraction is below the flammable limit and hence the mixing is insufficient to react. Therefore, as the result, the flame formed at low fuel velocity is characterized by non-premixed flames. For the flow field of co-flow configuration, flame stability was affected by fuel velocity as well as air velocity. the vortex generated by fuel stream has counter rotating direction against the air stream. Therefore, the momentum ratio between air and fuel stream was important to decide the flame blow out limit, which is result in the characteristic of the partially premixed reacting wake near extinction.

• Ecology and Resilient Infrastructure
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• 제6권3호
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• pp.145-153
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• 2019

본 연구는 저수로 변화를 통한 하천 복원이 수생 서식처에 미치는 영향을 파악하기 위하여 원주천을 대상으로 물리서식처분석을 수행하였다. 대상 어종은 원주천에 서식하는 우점종인 피라미를 대상으로 하였다. 흐름 분석은 2차원 모형인 River2D 모형을 사용하였으며, 서식처 분석은 서식처 적합도 곡선을 이용하여 서식처의 양과 질을 산정하는 서식처 적합도 모형을 사용하였다. 먼저 저수로 복원을 위하여 자연 하도에 가까운 형태로 복원을 하고 저수로 폭을 확대 및 축소하여 설계하였다. 그 결과 저수로 폭의 변화를 확대하였을 때 대상 어종의 가중가용면적은 각각 약 72% 향상되었으며, 저수로 폭을 축소하였을 때는 서식처가 약 25% 악화되는 것으로 나타났다.