• 한국농공학회:학술대회논문집
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• 한국농공학회 2003년도 학술발표논문집
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• pp.599-602
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• 2003

The objective of this study is to analyze the function of the paddy-field in purifying water quality. This study was carried out is based on the data in the six case studies. To improve purification function of paddy field, the following farming management is required. 1) A guideline to control the inlet and outlet of the paddy plot is need to minimize drainage water by means of a reasonable irrigation management. 2) A guideline for fertilizer application in consideration of loading nutrients dissolved in irrigation water. 3) The reuse system of agricultural drainage water is required to minimize impacts on water quality of surface water(reservoir and river).

• Environmental Analysis Health and Toxicology
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• 제16권4호
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• pp.153-159
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• 2001

The main point source of pollution of the Keumho river in Taegu, Korea, stems from waste from the areas of industrial complexes . Although it is widely accepted that pollutants in waste water negatively effects general water quality, it is difficult to evaluate the effluent effect because of varying conditions in ambient water and inconclusive knowledge of causative pollutants. To analyze the water in relation to the industrial effluent in the area, pH. temperature, conductivity, and Microtox toxicity of various river samples were measured. Water samples were collected every 2 hours for 36 hours from Keumho river and Dalseo stream. Data from continuous monitoring for 36 hours showed that effluent in Keumho river originated from Dalseo stream, which is near adjacent to industrial complexes. Change in toxicity and other factors tested during the 36 hours indicated that continuous monitoring was necessary for a satisfactory effluent toxicity test Furthermore, in addition to water quality monitoring, it was concluded that sediment toxicity also needed to evaluate effluent effects.

• 한국물환경학회지
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• 제22권5호
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• pp.887-894
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• 2006

Water quality in the Daecheong reservoir has been deteriorated by algal bloom every year. Algal bloom is propagated from eutrophicated tributary into the main body of the reservoir during the wet season. Nutrients from diffuse sources trigger the propagation of the algal bloom. This study is aimed to analyze relationship between the water current by the simulation and algae transport from the main body in the Daecheong reservoir including tributary where algal bloom has occurred seriously every year. Water quality model CE-QUAL-W2 was applied to analyze water movement in draught season (2001) and flooding season (2003). The result of simulation corresponded with the observed water elevation level, 63~80 m and showed stratification of the Daecheong reservoir. In the draught season, as velocity and direction off low in the reservoir was estimated to affect algae transport including nutrient supply from small tributary, algal blooms occurred in the stagnate zone of middle stream of the reservoir. On the other hand, in the flooding season, it was resulted in nutrient transport from upstream of main reservoir and nutrients were delivered up to downstream by fast water velocity. In result, algal blooms occurred in stagnate zone of reservoir downstream as the current of downstream was retarded according to dam outflow control.

• 한국수자원학회논문집
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• 제54권9호
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• pp.643-656
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• 2021

최근 국내 상수도 관리 기술은 고도로 발달하고 있으며, 이 과정에서 상수관망 내 용수공급 현황을 파악하고 예측하기 위한 컴퓨터 수리·수질 해석 모형은 핵심적인 역할을 수행하고 있다. 그러나 대규모 네트워크의 경우 컴퓨터 해석모형의 부담을 가중하고, 특히 짧은 계산시간 간격과 긴 모의 시간이 요구되는 수질해석의 경우, 막대한 계산시간이 소요되어 다양한 수질모의 및 분석이 어려운 경우가 발생한다. 본 연구에서는 대규모 상수관망시스템의 수질해석의 계산효율을 개선하기 위해 상수도 공급계통을 2단계로 계층화한 후, 계층화된 네트워크를 대상으로 수질모의를 수행하는 계층적 수질모의 기법을 제안하였다. 제안된 모의기법은 국내 대규모 상수도 네트워크에 적용하였으며, 다양한 염소투입농도 시나리오에 따른 잔류염소농도의 시공간적 분포를 모의하고 분석한 결과를 제시하였다.

• 한국물환경학회지
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• 제28권6호
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• pp.819-832
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• 2012

HSPF model based on BASINS was applied for the Hwaseong Reservoir watershed (HRW) to evaluate the feasibility of water quality management. The watershed was divided into 45 sub-basins considering various watershed environment. Streamflow was calibrated based on the measured meteorological data, discharge data of treatment plants and observed streamflow data for 2010 year. Then the model was calibrated against the field measurements of water qualities, including BOD, T-N and T-P. In most cases, there were reasonable agreements between observed and predicted data. The validated model was used to analyze the characterization of pollutant load from study area. As a result, Non-point source pollutant loads during the rainy season was about 66~78% of total loads. In rainy-season, water quality parameters depended on precipitation and pollutant loads patterns, but their concentration were not necessarily high during the rainy season, and showed a decreasing trend with increasing water flow. As another result of evaluation for load duration curves, in order to improve water qualities to the satisfactory level, the watershed managements considering both time-variant and pollution sources must be required in the HRW. Overall, it was found that the model could be used conveniently to assess watershed characteristics and pollutant loads in watershed scale.

• 한국물환경학회지
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• 제36권5호
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• pp.364-372
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• 2020

The "Master Plan for the Revitalization of Water in the Nakdong River" is designed for the fundamental improvement of water quality in the Nakdong River. The water quality and flow of the Nakdong River system tributaries was monitored in this study. Among the living environmental standard parameters of 195 rivers, BOD (Biochemical oxygen demand), T-P (Total phosphorus) and TOC (Total organic carbon) were assessed to analyze the water quality from 2012 to 2019. We examined the role of TOC. It was found that 12 rivers exceeded the water quality of the second grade (3.0 mg/L BOD standard, 0.1 mg/L T-P standard, 4.0 mg/L TOC standard) based on BOD and T-P concentrations: the Gumi stream, Gisegok stream, Yongha stream, Yongho stream, Changnyeong stream, Gajwa stream, Gwangok stream, Yeongsan stream, Toerae stream, Hwapo stream, Sangnam stream and Hogye stream. These rivers require strategies to improve the quality of the Nakdong River. Based on the ongoing project, it is possible to supplement the "Master Plan for the Revitalization of Water in the Nakdong River" and manage it after verifying it as a component of people's life and therefore used to establish water quality control measures.

• 한국물환경학회지
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• 제21권4호
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• pp.360-367
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• 2005

We have performed to analyze the trophic state resulting of Lake Yongdam as a result of water quality and nutrient concentration. Lake Yongdam is artifitial multi-purpose Dam resulting from the floods of 2001. The water quality of Lake Yongdam may affect the status of the Geum river basin including the Daecheong reservoir. It is necessary to understand the trophic state to assess water quality until stability after flooding. Water quality was surveyed using depth and hydraulic condition analysis. Further density flow was estimated for stratification and trophic state of Lake Yongdam by chlorophyll ${\alpha}$ concentration (2001~2004). And Environmental factors on chlorophyll ${\alpha}$ concentration were analyzed statistically. Trophic state was evaluated as the oligotrophic state at the main stream of the reservoir and eutrophic state at the upper stream in 2001, but evaluated as eutrophic state in 2002 and 2003 by TSI of Aizaki. From the results of multiple regression analysis using stepwise method, chlorophyll ${\alpha}$ concentration was shown to be very significant when nutrient concentration is high upon initial filling of the Dam. Chlorophyll ${\alpha}$ concentration varied according to sample site, season and year. Concentration were high in the upper stream of Lake Yongdam 4, algae bloom in these watershed were affected by location and high nutrient levels in the summer season which have in turn increased phytoplankton bloom into the reservoir.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2017년도 학술발표회
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• pp.545-545
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• 2017

본 연구에서는 낙동강 유역 본류와 주요 지천의 오염총량관리대상지점을 대상으로 수질 현황과 시공간적 수질특성을 분석을 위해 하수처리장과 주요 지천의 유입으로 인한 낙동강 본류 수질의 공간적 변화양상과 계절별 하천유량의 변화에 따른 수질특성을 분석하였다. 자료구축을 위해 국가수자원관리종합정보시스템(WAMIS)의 하천 공간 지형 자료, 국립환경과학원의 수질관측지점 공간지형자료, 그리고 전국오염원조사 자료의 하수처리장 공간 지형 자료를 이용하였다. 수질자료는 국립환경과학원 물환경정보시스템에서 제공하는 8일 간격 수질자료를 2004년부터 2015년까지 수집하여 이용하였고, 수집한 자료는 갈수기와 전체 기간에 대해 수질 항목(유량, BOD, T-N, T-P)별로 산술 평균하였다. 하수처리장 32개소의 방류수질 자료는 국립환경과학원의 전국오염원조사 자료를 2012년부터 2015년까지 수집하여 갈수기인 봄, 가을철에 대해 수질항목 별로 산술평균하였다.

• 한국환경과학회지
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• 제21권9호
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• pp.1115-1129
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• 2012

The objective of this study was to analyze long-term annual and seasonal trends of water chemistry on landuse patterns and seasonal precipitation using 72 sampling sites within Namhan River watershed during 2001-2010. Water quality, based on multi-parameters of water temperature(WT), dissolved oxygen(DO), biochemical oxygen demand(BOD), chemical oxygen demand(COD), suspended solids(SS), total nitrogen(TN), total phosphorus(TP), and electric conductivity(EC) varied largely depending on monsoon rain and landuse patterns such as forest, cropland, and residence. Concentrations of BOD and COD as an indicator for organic matter pollution, increased during summer monsoon season at the cropland and residential streams. Values of TN and TP were higher in residential streams than in the forest and cropland streams. In the meantime, DO values had weak relations to the landuse patterns of forest and cropland cover. Water quality was worst in cropland and residential streams, and also most degradated in 4th order streams. Overall, our results suggest that efficient water quality management is required in the cropland and residential landuse streams.

• 한국환경과학회지
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• 제18권12호
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• pp.1339-1347
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• 2009

This study tried to investigate and analyze the actual state such as the regional, classified, and material characteristics of the water quality in order to research the several factors by which the filtrated water of the total 250 cases can be polluted in the water tank. The 215 points (86%) clean the water tanks twice a year regularly and J-city has done the best job of cleaning the water tanks. The fifty points (20%) of the total 250 investigation points examine the water quality of the water tanks every year, however, the 175 investigation points (70%) do not execute the inspection of water quality. In the case of the regional characteristics in the water quality, the 23 points (46%) in H-county, the 17 points (34%) in S-county, and the 16 points (32%) in G-city are incongruent in the standard, and the incongruity ratio of the water quality in J-city is the lowest. The result of the classified incongruity shows that total coliforms were found at the 61 investigation points, mesophilic bacteria were found at the 27 points, and turbidity was found at the 12 points. In the case of the material incongruity, concrete was found at the 63 investigation points as the most distinguished factor, and FRP (fiberglass reinforced plastic) at the 23 points, SMC (sheet molding compound) at the 12 points, and stainless steel was found at the 2 points.