• 한국방재학회 논문집
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• 제10권2호
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• pp.111-122
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• 2010

한강의 잠수교와 둔치는 장마철에 큰 홍수가 발생하면 침수가 되기 때문에 시민들의 안전과 편의를 위해 홍수로 인한 침수 발생시간을 예측하는 것은 대단히 중요하다. 본 연구에서는 FLDWAV모형을 이용하여 한강하류부의 팔당댐 방류량과 황해(서해) 조석이 한강하류부 수위에 미치는 영향을 분석하였다. 연구 대상구간은 팔당댐 하류부에서 전류지점까지이며, 조석영향을 고려하기위해 하류경계조건인 전류수위는 팔당댐방류량과 인천조위를 이용한 다중선형회귀분석을 통해 산정된 예측 전류수위를 사용하였다. 본 연구에서는 잠수교와 주요 둔치에서 수위상승도달시간을 산정하였고, 팔당댐 방류유형과 황해조석에 따른 수위상승도달시간을 팔당댐 방류량의 함수인 2차다항식으로 나타냈다.

• 한국수자원학회논문집
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• 제30권2호
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• pp.131-141
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• 1997

본 연구에서는 저류함수법과 Loopnet(부정류해석모형) 모형으로 홍수예측 시스템을 구성하여 대청댐의 방루에 따른 하류지역의 홍수영향을 에측하여 보았다. 대청댐 하류부에 지역빈도 분석방법(L-모멘트)으로 강우량을 산정하고, 홍수예측시스템으로 금강 하류부의 홍수추적을 실시하여 빈도별 홍수량을 산정하였다. 또한 대청댐의 방류에 따른 금강 하루 주요지점의 홍수량, 홍수위 및 방류량 도달시간을 산정하여 홍수발생시 대청댐 운영의 지표포 활동할 수 있도록 하였다.

• 한국농공학회지
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• 제31권1호
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• pp.117-130
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• 1989

In this study, an implicit one-dimensional model, DWRM(Dynamic Wave Routing Model) was developed by using the four-point weighted difference method. By applying the developed model to the Keum River, the parameters were calibrated and the model applicability was tested through the comparison between observed and computed water levels. In addition, the effects of the construction of an estuary dam to the flood wave were estimated as a result of the model application. The results of the study can be summarized as follows; 1. The roughness coefficients were evaluated by comparison between observed and computed water level at Jindu, Gyuam and Ganggyeung station in 1985. The Root Mean Squares for water level differences between observed and computed values were 0.10, 0.11, 0. 29m and the differences of peak flood levels were 0.07, 0.02, 0. 07m at each station. Since the evaluated roughness coefficients were within the range of 0.029-0.041 showing the realistic value for the general condition of rivers, it can be concluded that the calibration has been completed. 2. By the application of model using the calibrated roughness coefficients, the R. M. S. for water level differences were 0.16, 0.24, 0. 24m and the differences of peak flood level were 0.17, 0.13,0.08 m at each station. The arrival time of peak flood at each station and the stage-discharge relationship at Gongju station agreed well with the observed values. Therefore, it was concluded that the model could be applied to the Keum River. 3. The model was applied under conditions before and after the construction of the estuary dam. The 50-year frequency flood which had 7, 800m$^3$/sec of peak flood was used as the upstream condition, and the spring tide and the neap tide were used as the downstream condition. As the results of the application, no change of the peak flood level was showed in the upper reaches of 19.2km upstream from the estuary dam. For areas near 9.6km upstream from the estuary dam, the change of the peak flood level under the condition before and after the construction was 0. 2m. However considering the assumptions for the boundary conditions of downstream, the change of peak flood level would be decreased.

• 한국물환경학회지
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• 제36권5호
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• pp.445-452
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• 2020

Tributary is a part of life space for people and a very important place that accommodates rest recreation and other daily activities. absolutely insufficient basic data about water quality and flow rate are available for basin management. Efficient water and basin management systems, which are also supported by local residents can be established by securing such basic data of major tributaries in the Nakdong river system. In this study, the fluctuation characteristics of upstream and downstream water pollution levels were compared using the measurement results of the water environment measurement network and the tributary monitoring project for the gyeseong-stream and Hwapo-stream in the Nakdong-miryang watershed. In 2017, when water pollution is the highest, it was confirmed that the annual average rainfall was the lowest. Although the upstream and downstream water quality tendencies of the Gyeseong-stream are similar, the water quality concentrations of the Gyeseong-stream are relatively different. But although the Hwapo stream has various causes of pollution, there was not much difference in the level of pollution between the upper and lower streams. In addition, both rivers need the ability to purify rivers by securing sufficient water for river maintenance, and if the correlation between water quality items can be inferred through continuous monitoring of tributaries where the aspect of water quality change is unclear, water quality management Determined to be efficient operation.

• 한국수자원학회논문집
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• 제35권5호
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• pp.525-539
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• 2002

용담댐의 건설에 따른 방류조건의 변화가 대청호의 유입수질에 미치는 영향을 파악하기 위하여 WASP5 모델을 이용하여 BOD, 총인 그리고 총질소 농도를 예측하였다. 수질 예측 시나리오는 크게 다음과 같이 세 가지로 구분하였다; 첫째, 금강의 유량이 대청댐의 운영이 시작된 이래 최대 갈수년(1994)과 최대 풍수년(1987)과 같다고 보는 두 가지 조건, 둘째 용담댐에서 방류되는 유량을 연구기간 중(1998년) 실측된 유량과 같다고 보는 경우와 용담댐 방류 계획안에 따라 각각 5.4, 8.9, 12.4, 16.4 ㎥/s로 방류되는 경우 등 다섯 가지 유량조건, 셋째, 용담호에서 방류되는 수질이 1998년에 실측된 수준을 유지하는 경우와 우리 나라 수질기준으로 1급수와 2급수에 해당되는 경우 등 세 가지 수질 조건. 수질 예측 결과 용담댐으로부터의 방류량의 변화는 금강의 수질과 밀접한 관계를 나타내었으며 금강의 수량이 적은 경우 용담호의 영향은 더욱 뚜렷하게 나타났다. 특히 총질소와 총인 농도의 경우는 각 조건에 대하여 용담댐으로부터의 방류량이 증가됨에 따라 점차로 수질이 개선되는 경향을 나타내었다. 그러나 BOD 농도의 경우는 실측 수질(98년 환경부 측정자료)이 1급수(1 mg/ι) 보다 양호한 수질을 나타내므로 1급수(1 mg/ι)와 2급수(3 mg/ι)의 수질로 방류되는 것을 가정하는 경우에는 방류량의 증가에 따라 용담호 하류의 수질은 오히려 악화되는 결과를 나타내는 것으로 예측되었다. 용담호 부근의 현재 수질은 총질소의 경우는 5급수의 기준(1.5 mg/ι)을 상회하며, 총인의 농도는 3급수 (0.03∼0.06 mg/ι) 정도의 수질을 나타낸다. 유역에서 영양염류의 오염부하를 관리하는 것이 기술적, 경제적으로 한계가 있는 것을 감안할 때, 용담호 방류수내의 영양염류 농도는 크게 개선되지 못할 것으로 예상된다. 따라서 용담호의 방류량 변화가 대청호의 수질에 미치는 영향은 용담호와 용담호 하류부의 수질 및 유량조건에 따라 각각 다르며, 합리적인 수자원의 관리를 위해서는 현실적인 자료 및 여건을 충분히 고려하여 분석하고 판단하는 것이 바람직하다.

• 한국물환경학회지
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• 제23권5호
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• pp.591-599
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• 2007

The quality of water released from a stratified reservoir is dependent on various factors such as the location and shape of intake facility, structure of reservoir stratification, profile of water quality constituent, and withdrawal flux. Sometimes, selective withdrawal capabilities can provide the operational flexibility to meet the water quality demands both in-reservoir and downstream. The objective of this study was to evaluate the performance of a one-dimensional reservoir selective withdrawal model (SELECT) as a tool for supporting downstream water quality management for Daecheong and Imha reservoirs. The simulated water quality variables including water temperature, dissolved oxygen (DO), conductivity, turbidity were compared with the field data measured in tailwater. The model showed fairly satisfactory results and high reliability in simulating observations. The coefficients of determinant between simulated and observed turbidity values were 0.93 and 0.95 for Daecheong and Imha reservoirs, respectively. The outflow water quality was significantly influenced by water intake level under fully stratified condition, while the effect of intake amount was minor. In conclusion, the SELECT is simple but effective tool for supporting downstream water quality prediction and management for both reservoirs.

• 환경영향평가
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• 제20권1호
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• pp.37-48
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• 2011

Recently, the social and environmental functions of nature river are important due to the increase of expectation for river restoration. So it should be considered the effect of vegetation affecting the conveyance capacity and hydraulic resistance. However, it has not yet proposed a objective standard and modeling method to estimate the effect of conveyance capacity according to vegetaion distribution in the watercourse such as water level or velocity. Therefore, this study simulates the variations of water level and velocity using 3-dimensional hydrodynamic model, EFDC, to consider a conveyance capacity in downstream of the Soyang Reservoir. The simulation results were validated using statistical index such as F-test and T-test. As results, the water level rises about 0.01 to 0.47m and velocity difference are about -0.95m/s to 0.23m/s.

• 한국수자원학회논문집
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• 제47권2호
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• pp.107-117
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• 2014

본 연구에서는2007년 제주지역을 강타한 태풍 '나리' 이후 홍수조절을 위해 한천유역에 설치된 저류지의 효과를 정량적으로 평가하였다. 이를 위해 2010년 태풍 '뎬무'의 내습 시, 한천 상 하류에 위치한 하천유량관측소의 자료와 저류지 유입량 자료를 이용하여 한천저류지 운영이 하류지역에 미치는 홍수저감 효과를 검토하였다. 분석결과, 하류지역에서의 실제 하천수위는 3.44m를 기록하였으나, 수위-유량 관계식, 유출전파속도, 저류지 유입량 등을 활용하여 저류지가 운영되지 않았을 경우의 하류지역 하천수위를 분석한 결과 4.16m로 예측되었다. 이와 같은 결과는 한천유역에 설치된 저류지의 홍수저감 효과를 분명하게 보여주는 것으로 향후 유사한 사상에 대해서도 적절한 기여를 할 수 있을 것으로 판단되었다.

• Environmental Engineering Research
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• 제19권2호
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• pp.175-184
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• 2014

Weirs are conventional structures that control water level and velocity in streams to facilitate water resource management. Despite many weirs built in streams, there is little information how weirs change hydrology regime and how that translates to sediment and phosphorus (P) responses. This study evaluated the influence of weirs on P retention and mobilization in an urban tributary of the Han River in Korea. Total P concentrations in sediments upstream of weirs were higher than the downstream site, mainly due to the increase of potentially available fractions (labile P and aluminum- and iron-bound P) (p < 0.05). Equilibrium phosphorus concentrations ($EPC_o$) were lower than soluble reactive phosphorus (SRP) concentrations of stream waters, but there was an increasing trend of sediment $EPC_o$ upstream of weirs compared to the downstream site (p < 0.001) indicating a greater potential for P release upstream of weirs. Sediment core incubation showed that SRP release rates upstream of weirs were higher than the downstream site under anoxic conditions of the water column (p < 0.01), but not under oxic conditions. SRP release rates under anoxic conditions were greater than that measured under oxic conditions. Un-neutral pH and increased temperature could also enhance SRP release rates upstream of weirs. We conclude that weirs can increase P retention within stream sediments and potentially promote significant P releases into waters, which in turn cause eutrophication.

• 한국환경복원기술학회지
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• 제4권3호
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• pp.30-37
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• 2001

This study was conducted to investigate physicochemical property changes from July 1998 to August 2001 in Mt. Bukhansan National Park. Four water sampling points were selected to measure the quality of stream water in the northeastern part of the Mt. Bukhansan National Park. The results were summarized as follows; In spring, the average pH of stream water was below the first class of the river water quality standard, while it was normal level in summer. The average electrical conductivity was about 2.3~3.3 times higher in downstream water than in upstream water during spring and summer. The contents of anions($Cl^-$, $NO{_3}^-$, $SO{_4}^{2-}$) were about 1.1~7.4 and 0.4~11.4 times higher in downstream than in upstream water, respectively. These results indicate that water quality was poorer in downstream than in upstream water. We suggest that stream water in the Mt. Bukhansan National Park should be protected from impacts of snow melting mineral particles in spring season and human impacts like wastewater of point source in summer season.