• 한국물환경학회지
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• 제34권5호
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• pp.487-493
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• 2018

Urban stormwater runoff is the one of the most extensive causes of deterioration of water quality in streams in urban areas. Especially, in the Suyeong River watershed, non-point sources from urban-residential areas are the most common cause of water pollution. Also, it has been ascertained that BOD and COD as indexes of organic matter, have limitation on management of Suyeong River's water quality. In this study, changes of organic matter properties of Suyeong River from inflow of non-point source during rainfall were investigated. Fractions of organic matters were analyzed using water samples collected at two sites (Suyeong River and Oncheon Stream) during a rain event. Variations of dissolved organic carbon (DOC) concentration by rainfall were similar to flow rate change in the river. Distribution of organic matter fraction according to change of rain duration revealed that while hydrophilic component increased at initial rainfall, the hydrophobic component was similar to change in dissolved organic carbon (DOC) concentration. Also, the relative proportion of hydrophilic components in organic matter in river water increased, due to rainfall. Results of biodegradation of organic matters revealed that decomposition rate of organic matters during rainfall was higher than that of during a non-rainfall event.

• 한국물환경학회지
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• 제34권4호
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• pp.363-374
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• 2018

The Han River serves as an important water resource for the city of Seoul, Korea and in the neighboring metropolitan areas. From the Paldang dam to the Jamsil submerged weir, the 4 water intake stations that are located for the Seoul metropolitan population were under review in this study. Therefore the water quality management in this section is very important to monitor, analyze and review to rule out any safety concerns. In this study, a 3-D hydrodynamic model, EFDC (Environmental Fluid Dynamics Code), was applied to the downstream of the Paldang Dam in the Han River, which is about 23 km in length, to determine issues related to water resource management. The 3-D grid was composed of 2,168 horizontal grids and three vertical layers. In this case, the hydrodynamic model was calibrated and verified with an observed average daily water surface elevation, water temperature and flow rate data for 3 years (2013~2015). The developed EFDC model proved to reproduce the hydrodynamics of the Han River well. The composition ratios of the noted incoming flows at the monitored intake stations for 3 years and their flow patterns in the river were analyzed using the validated model. It was found that the flow of the Wangsuk Stream depended on the Paldnag dam discharge, and it was noted that the composition ratios of the stream at the intake stations changed accordingly. In a word, the Wangsuk Stream moved mainly along the right bank of the Han River under the condition of a normal dam flow. As can be seen, when the dam discharge rate was low, the incidence of lateral mixing was often seen. The scenario analyses were also conducted to predict the transport of conservative pollutants as in the case of a chemical spill accident. Generally speaking, when scenarios were applied, the arrival time and concentration of pollutants at each intake station was thus predicted.

• 대한환경공학회지
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• 제35권3호
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• pp.151-164
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• 2013

본 연구에서는 한강수계에 대하여 다차원 시변화 유기물 및 영양상태 모델을 적용하여 2007년에 관측된 수질 자료를 이용해 그 재현성을 검토하였다. 모델 적용 결과 TN, TP, Chl-a, BOD 농도의 시변화를 모델이 적절히 재현하고 있는 것으로 나타났다. 따라서 본 모델 시스템은 한강수계 내 하천-호수 연속 시스템에 대하여 수리 및 수온 해석뿐만 아니라 유기물 및 영양상태 해석에도 적용이 가능한 것으로 판단된다. 모델 보정 결과를 바탕으로 TN, TP, Chl-a, BOD에 대한 한강수계 내의 시 공간적 농도 변화를 분석하였다. 모델은 호수 구간 표층과 하천 구간에 대하여 각 구간별로 수질의 시변화를 적절히 모의하였고 이를 통하여 한강수계 내의 공간적 농도 분포를 비교하는 것이 가능했다. 본 연구에서 구축한 다차원 시변화 모델 시스템은 하나의 모델로 팔당호와 그 상류 수계의 수질을 통합적으로 분석하는 것이 가능하므로, 한강 수계에 대한 통합적인 수질 관리에 효과적으로 사용될 수 있을 것으로 기대된다.

• 환경영향평가
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• 제22권4호
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• pp.319-327
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• 2013

This study was conducted to identify runoff characteristics of pollutants using flow duration curve(FDC) and load duration curve(LDC) in Youngbon A watershed during 2009~2011. A flow rate and pollutant load in the study watershed were estimated by equation of stage-discharge and discharge-loads rating curve. From these methods, BOD, T-N, and T-P have evaluated whether water quality standards would have attained. Results showed that BOD loads of about 50% plotted above the LDC, while T-N and T-P loads of about 50% plotted below the curve. It means that BOD of about 50% have exceeded the water quality criteria, while T-N and T-P of about 50% have complied with the water quality standards. Meanwhile, BOD, TN and T-P loads plotted above the LDC of low flows, implying that they were more affected by point pollution sources than nonpoint pollution sources in the study watershed.

• 한국환경과학회지
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• 제25권6호
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• pp.767-787
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• 2016

In this study, we analyzed on-site monitoring data for 15 tributaries in Geumho watersheds for 3 years (2011-2013) in order to sort out priorities on water quality characteristics and improvement. As a result of estimating contribution to contamination of the tributary rivers, Dalseocheon showed the highest load densities, despite the smallest watershed area, with 22.7% $BOD_5$, 30.7% $COD_{Mn}$, 31.3% TOC and 47.6% TP. After conducting PCA (principal component analysis) and FA (factor analysis) to analyze water quality characteristics of the tributary rivers, the first factor was classified as $COD_{Mn}$, TOC, EC, TP and $BOD_5$, the second factor as pH, Chl-a and DO, the third factor as water temperature and TN, and the fourth factor as SS and surface flow. In addition, arithmetical sum of each factor's scores based on grading criteria revealed that Dalseocheon and Namcheon were classified into Group A for their highest scores - 96 and 93, respectively -, and selected as rivers that require water environmental management measures the most. Also, water environmental contamination inspection showed that Palgeocheon had the most number of aquatic factors to be controlled: $BOD_5$, $COD_{Mn}$, SS, TOC, T-P, Chl-a, etc.

• 대한토목학회논문집
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• 제40권1호
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• pp.127-133
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• 2020

해안에 위치한 대부분의 하수 처리장의 처리수는 직접 또는 하천을 통해 해안으로 배출된다. 따라서, 하수 처리장에서 배출되는 처리수의 수질은 하천 및 해안으로 방류되는 수질에 영향을 미친다. 본 연구에서는 연안에 인접한 하수처리장으로부터 배출되는 처리수가 연안 환경에 미치는 영향을 파악하기 위해 현장조사와 수치 시뮬레이션을 수행하였다. 해안에 미치는 영향을 파악하기 위해 처리수가 방류된 하천 및 하구 주변에서 채수된 시료로 수질과 저질을 분석한 결과, 하수처리장에서 배출된 처리수는 설계기준을 초과하지 않은 상태로 하천으로 방류되고 있으나, 하구를 통해 해안으로 방류되는 수질은 처리수보다 오염된 상태였다. 해안방류수의 수질악화에 대한 원인은 하구 주변에서 나타난 연안표사에 의해 하구가 일시적으로 퇴적되고, 하구폐색 현상이 발생하여, 하구에서의 정체시간이 증가함에 따라 처리수가 유입된 하천수가 하계에 부영양화되어 방류됨에 따라, 하구 주변에서 저질, 수질 및 해양 생물에 영향을 미치는 것으로 분석되었다. 따라서, 연안표사가 강한 동해안의 경우, 해양으로 방류되는 하수처리시설을 계획할 경우, 연안표사에 의한 하구폐색과 같은 처리수의 수질에 미치는 영향에 대한 면밀한 검토가 반드시 필요할 것으로 판단된다.

• 한국환경과학회지
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• 제28권3호
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• pp.357-369
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• 2019

In this study, the water quality components (pH, BOD, COD, TOC, SS, DO, TP) and the water quality, observed for 10 years (2008~2017) in the five tributaries of the Nakdong River with the highest flow rates, were analyzed. Monthly levels of the water quality components were estimated and regression functions were used to quantitatively explain the changes in the BOD and COD components, with respect to the TOC components. The results of analyzing the water quality levels in terms of the living environmental standards show that the lowest water quality was observed midstream (ST-3) and the highest water quality was observed upstream (ST-1 and ST-2). The regression function was estimated to be a linear function in all five tributaries, and the goodness of fit of the function was high upstream (ST-2), midstream (ST-3), and downstream (ST-4). According to the regression analysis using the observation data from 2008~2017, we found that the consumption of dissolved oxygen increased with an increase in organic matter in the major tributaries of the Nakdong River.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2007년도 학술발표회 논문집
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• pp.1387-1391
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• 2007

In this study, water quality prediction that is necessary to water quality forecasting system is performed using 2-D river analysis models RMA-2 and RAM4. RAM4 is suitable to water quality forecasting system cause it is possible to put in the pollutants as a mass type boundary condition. Instant injections of pollutants at Yongdamdaegyo Bridge in Namhangang River are simulated and the behavior of pollutant cloud is observed. The effects of water quality accident to Paldang 2 water intake plants in Paldangho Lake is analyzed with time variation. And extra flow simulation is performed for mitigation of pollution. Several cases of water quality forecasting system at home and abroad are investigated and the direction of water quality forecasting system is presented.

• 한국환경과학회지
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• 제21권8호
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• pp.965-975
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• 2012

Loading of NPS pollutant was valued through simulation by using BASINS/HSPF model which can simulate runoff volume in rainfall by time. For the verification of the model, it was analyzed the scatter diagram of the simulation value and measure value of water quality and runoff volume in Dongcheon estuary. Using the built model, a study on the time-variant characteristics of runoff and water quality was simulated by being classified into four cases. The result showed the simulation value was nearly same as that of the measured runoff. In the result of fit level test for measured value and simulated value, correlation of runoff volume was computed high by average 0.86 and in the water quality items, fit level of simulation and measurements was high by BOD 0.82, T-N 0.85 and T-P 0.79.

• Spatial Information Research
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• 제4권2호
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• pp.147-157
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• 1996

노촌 소유역에서 발생된 오염물질의 이동과 이에 따른 하천의 수질변화를 공간적으로 파악하기 위하여 이와 관련된 기존의 모형들과 지리정보시스템을 통합함으로써 소유역 하천수질관리시스템을 개발하였다. 오염 물질의 하천유달률을 계산하기 위한 간단한 오염부하모형, 유역의 유출을 발생시키기 위한 Tank모형 그리고 하천에서의 수질을 예측하기 위한 QUAL2E모형이 본 연구에 적용되었다. 시스템은 경기도 이천군과 용인군에 위치한 복하천유역에 적용하였으며, 발생오염물질 분포도, 배출오염물질 분포도, 하천으로의 유달률 분포도 및 주요하천지점에서의 수질현황도 등을 구축하였다.