• 환경영향평가
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• 제18권2호
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• pp.59-67
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• 2009

Water quality of the Lake Youngrang in the Sokcho City is eutrophic. Jangcheon is the largest inflow source to the lake. Major pollutant sources are stormwater runoff from resort areas and various land uses in the Jangcheon watershed. A storm sewer on the southern end of the lake is also an important pollution source. In this study, water quality modelling for Lake Youngrang was carried out considering the rainfall-runoff pollution loads from the watershed. The rainfall-runoff curves and the rainfall-runoff pollutant load curves were derived from the rainfall-runoff survey data during the recent 4 years. The rainfall-runoff pollution loads and flow from the Jangcheon watershed and the storm sewer were estimated using the two kinds of curves, and they were used as the flow and the boundary data of the WASP model. With the measured water quality data of the year 2005 and 2006, WASP model was calibrated. Non-point pollution control measures such as wet pond and infiltration trench were considered as the alternative for water quality management of the lake. The predicted water quality were compared with those under the present condition, and the improvement effect of the lake water quality were analyzed.

• 환경위생공학
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• 제15권3호
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• pp.101-119
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• 2000

In order to establish water quality management planning in some watershed, water quality of the future of the watershed should be predicted first. The Yongsan river various pollutant sources ; sewage, industry, livestock, farming and so on. And pollutants from these sources are likely to increase even though a number of publicly owned treatment works(POTWs) are founded. Therefore, it is estimated that water quality if the river would be even worse than now in near future. In this study, water quality of the future(2001, 2006) on the Yongsan river was simulated with QUAL2E model. Concentration of three water quality parameters(BOD, T-N, T-P) was predicted according to dry season, low flow season, average flow season of the river with and without POTWs. The results of this study showed the significant contrast in concentration between with and without POTWs, specially in terms of T-N and T-P. Therefore, POTWs must be founded around the Yongsan river and more advanced treatment should be considered. And because these parameters are mostly affected by polluants from upper watershed, including Kwangiudcheon, water quality management planning on the Yongsan river might be focused on this area.

• 한국물환경학회지
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• 제29권1호
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• pp.66-73
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• 2013

Total Maximum Daily Loads (TMDLs) system was introduced to manage pollution load of watershed and to improve water quality of unit watershed so that it is possible to protect dringking water soureces. Load allocation observation is the most important factor in TMDLs system. Because if load allocation is not observed, it is difficult to achieve water quality goal of unit watershed. Also it is impossible to improve water quality of the drinking water sources. Therefore it is necessary to apply some kind of sanctions (penalty) in case of excess of load allocation. The sanctions have to be, however, applied differently based on various reduction plan types, i.e., using the reduction load planed in 2nd phase, delay the completion, additional reduction in 2nd phase, error of the pollution sources, etc. Moreover, the penalty load should be properly imposed, lest it should be overburden the provence. The reduction load trade inter province must be restrictively permmitted only the same unit watershed.

• 한국환경기술학회지
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• 제19권6호
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• pp.514-527
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• 2018

본 연구는 전라북도 섬진강수계의 수질을 예측 분석하여 수질을 개선하는 시나리오를 구성하여 결과를 산출하였다. 결과적으로 공공하수처리시설의 배출수 관리강화 및 오염물질 관리 개선과 국내 축산계 감소에 따라 수질이 최대 BOD 15.32 %, T-N 7.17 %, T-P 62.86 %로 개선된 것으로 분석되었다. 효율적인 감축 계획수립, 오염부하량 저감계획, 하수 처리 효율 증대 계획, 공공하수처리시설 확대로 인한 오염물질 감소 및 총 오염 부하 동물 배설물 에너지 회수 등 다양한 삭감계획을 보완한 것으로 분석되었다. 자연증가 및 경제발전을 고려한 수질 개선 계획에 대한 연구개발은 수질 개선에 효율적이다.

• 상하수도학회지
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• 제33권4호
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• pp.259-268
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• 2019

One of the most effective methods to consistently ensure the safety of a tap water supply can be achieved by application of a comprehensive risk assessment and risk management approach for drinking water supply systems. This approach can be termed water safety plans(WSP) which recommended by WHO(world health organization) and IWA(international water association). For the introduction of WSP into Korea, 150 hazards were identified all steps in drinking water supply from catchment to consumer and risk assessment tool based on frequency and consequence of hazards were developed. Then, developed risk assessment tool by this research was implemented at a water treatment plant($Q=25,000m^3/d$) to verify its applicability, and several amendments were recommended; classification of water source should be changed from groundwater to stream to strengthen water quality monitoring contaminants and frequencies; installation of aquarium to monitor intrusion of toxic substances into raw water; relocation or new installation on-line water quality analyzers for efficient water quality monitoring; change of chlorination chemical from solid phase($Ca(OCl)_2$) to liquid phase(NaOCl) to improve soundness of chlorination. It was also meaningful to propose hazards and risk assessment tool appropriate for Korea drinking water supply systems through this research which has been inconsistent among water treatment authorities.

• 한국환경과학회지
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• 제19권1호
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• pp.39-45
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• 2010

When the Juam multipurpose dam which is connected with existing large water supply facilities is finished, water environment is changed from stream to lake. The changed quality of water should be examined. In this study, the result of water quality forecasting is analysed and an effective management plan of water quality is presented. Tn this study, the WASPS model that is a dynamic water quality simulation model was selected to forecast the water quality. This model forecasts movement of change of pollutants. For an application of the model, the subject areas were divided into seventeen sub-areas by considering change temperature depending measuring points and on depth of water. Meteorological data collected by the meteorological observatory and data about quality measured by the Korea Water Resources Development Corporation were used for an operation of the model. As a result of quality examination through quality data and estimated pollutant loading, the water quality environment criterion was grade II and the nutritive condition was measured as meso-graphic grade. In this study, an effective management was planned to improve water quality by reducing pollution load. According to the result of examination, when more than 30% of BOD was reduced it was recorded that the environment standard of water quality was improved to the second grade.

• 환경정책연구
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• 제10권4호
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• pp.61-80
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• 2011

생분해성 물질 지표인 BOD 중심의 환경규제와 환경기초시설의 집중 투자로 인하여 전국적인 BOD 오염도는 지속적으로 개선되었다. 그러나 COD 등의 난분해성 물질은 주요 상수원을 포함하여 전국적으로 정체 또는 증가 추세를 보임에 따라 BOD 관리체계의 한계를 드러냄과 동시에 정체수역 증가와 같은 수체 특성변화의 반영 등 달라진 환경여건을 반영할 수 있는 지표의 필요성이 끊임없이 제기되고 있다. 따라서 본 논문에서는 수체의 변화된 유기물질 오염상태를 적절히 관리할 수 있는 유기물질 관리지표를 선정하였다. 지표전환의 항목으로 $COD_{Cr}$와 TOC를 검토해 본 결과 $COD_{Cr}$보다는 TOC를 향후 유기물질 관리지표로 선정함이 적정한 것으로 나타났다. TOC는 유기물지표로서 대표성,국제적 통용성, 모니터링 프로그램의 용이성, 분석기술의 유무, 정밀도 및 정확도, 분석에 소요되는 시간, 운전의 용이성, 소독부산물의 관리, 기존정책과의 연계성, 외국사례여부, 국내적용사례, 수생태계와의 상관성 등에 대한 평가 결과 타당한 것으로 나타났다.

• 상하수도학회지
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• 제34권1호
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• pp.35-43
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• 2020

Turbidity has various effects on the water quality and ecosystem of a river. High turbidity during floods increases the operation cost of a drinking water supply system. Thus, the management of turbidity is essential for providing safe water to the public. There have been various efforts to estimate turbidity in river systems for proper management and early warning of high turbidity in the water supply process. Advanced data analysis technology using machine learning has been increasingly used in water quality management processes. Artificial neural networks(ANNs) is one of the first algorithms applied, where the overfitting of a model to observed data and vanishing gradient in the backpropagation process limit the wide application of ANNs in practice. In recent years, deep learning, which overcomes the limitations of ANNs, has been applied in water quality management. LSTM(Long-Short Term Memory) is one of novel deep learning algorithms that is widely used in the analysis of time series data. In this study, LSTM is used for the prediction of high turbidity(>30 NTU) in a river from the relationship of turbidity to discharge, which enables early warning of high turbidity in a drinking water supply system. The model showed 0.98, 0.99, 0.98 and 0.99 for precision, recall, F1-score and accuracy respectively, for the prediction of high turbidity in a river with 2 hour frequency data. The sensitivity of the model to the observation intervals of data is also compared with time periods of 2 hour, 8 hour, 1 day and 2 days. The model shows higher precision with shorter observation intervals, which underscores the importance of collecting high frequency data for better management of water resources in the future.

• 대한토목학회논문집
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• 제13권2호
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• pp.295-305
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• 1993

본 연구의 목적은 오염 심화된 하천 수질개선을 위한 희석수량 및 점오염원을 최적 제어할 수 있는 수질관리 시스템개발에 대한 이론적 방법론을 연구하는데 있다. 시스템 제어변수로는 하천 유하량과 처리장 방출수의 농도수준을, 상태변수로는 DO, BOD, COD, SS를 선택하였고, 시스템 해법으로는 비선형기법인 augmented Lagrangian 기법을 활용하였다. 개발된 시스템을 검증하기 위한 적용대상 하천으로는 오염 심화된 도시하천인 무심천을 선정하였다. 검증과정으로 부터, 개발된 방법론은 도시하천 뿐만아니라 수계 전반에 걸친 폭넓은 분석에도 적합할 것으로 사료되었으며, 제한된 수자원의 효율적 운영을 위한 방안을 제시하는데도 유용한 도구가 될 수 있을 것으로 판단되었다.

• 한국물환경학회지
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• 제31권6호
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• pp.732-738
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• 2015

Water quality in four major river basin in Korea was managed with Total Maximum Daily Load (TMDL) System. The unit watershed in TMDL system has been evaluated with Target Water Quality (TWQ) assessment using average water quality, without considering its volume of water quantity. As results, although unit watershed are obtained its TWQ, its allocated loads were not satisfied and vice versa. To solve these problems, a number of TWQ assessments with using Load Duration Curve (LDC) have been studied at other watersheds. The purpose of this study was to evaluate achievement of TWQ with Flow Duration Curve (FDC) and Load Duration Curve(LDC) at 26 unit watersheds in Han river basin. The results showed that achievement rates in TWQ assessment with current method and with LDC were 50~56 % and 69~73%, respectively. Because of increasing about 20% of achievement rates with using LDC, the number of exceeded unit watershed at Han river Basin was decreased about 4~6 unit watersheds.