• 한국물환경학회지
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• 제36권2호
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• pp.116-124
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• 2020

This study aims to identify the characteristics of organic matter and pollutant sources using water quality and stable isotope ratios (δ¹⁵N, δ¹³C) of the two inflow tributaries (Gulpo (GP) and Anyang (AY) streams). Water samples were analyzed in June and September 2018, and the results showed that the concentrations of nutrients, such as TN and NO₃-N, were increased at GP4, which is located at the downstream of sewage treatment facilities(STFs). TOC and TN ratios showed a strong positive correlation (R² = 0.77, p<0.01) at all points except for GP4. The results of GP's stable isotope ratio analysis do not appear to be a constant cluster compared to AY because GPs with large amounts of pollutants from the industry (metal processing companies, etc.) have less tributary, shorter waterway and significantly different external sources. This could be attributed to different sources of external inflow despite its smaller number of tributaries and shorter waterways than AY. In the first half of the year, the δ¹⁵5N of GP4 was affected by discharge of STFs, while AY3 seemed to have an influence of tributary than the discharge of STFs. Consequently, using water quality, stable isotope ratio and C/N, the sources of contamination in two streams with different contaminants were identified and origin was estimated.

• 환경영향평가
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• 제23권3호
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• pp.187-196
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• 2014

The objective of this study is to evaluate and analyze Osu stream watershed water environment system. The data were collected from January 2009 to December 2011 including water temperature, pH, DO, EC, BOD, COD, TOC, SS, T-N, T-P and discharge. The data were used for principle component analysis and factor analysis. The results are as followes. The primary factors obtained from both the principal component analysis and the factor analysis were BOD, COD, TOC, SS and T-P. Once principal component analysis and factor analysis have been performed with the collected data and then the results will be applied to both simple regression model and multiple regression model. The regression model was developed into case 1 using concentrations of water quality parameters and case 2 using delivery loads. The value of the coefficient of determination on case 1 fell between 0.629 and 0.866; this was lower than case 2 value which fell between 0.946 and 0.998. Therefore, case 2 model would be a reliable choice.The coefficient of determination between the estimated figure using data which was developed to the regression model in 2012 and the actual measurement value was over 0.6, overall. It can be safely deduced that the correlation value between the two findings was high. The same model can be applied to get TOC concentrations in future.

• 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.

• Ecology and Resilient Infrastructure
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• 제4권4호
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• pp.226-236
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• 2017

본 연구에서는 경안천의 10년 수질변화 특성을 분석하고 유량-오염부하량 관계식을 이용하여 고찰하였다. 통계분석을 이용하여 수질 항목간의 상관분석과 수질에 영향을 미치는 요인분석을 하였다. 수질변화 특성 결과 $BOD_5$, $COD_{Mn}$, TOC는 연도별로 증가와 감소를 반복하는 것으로 나타났고 TN, TP는 연도별로 감소하는 것으로 나타났다. 유량-오염부하량 관계식을 통한 오염물질 유출특성결과 유량 증가 시 $BOD_5$, $COD_{Mn}$, TOC, TN농도는 감소하였으나, TP농도 변화에는 영향을 주지 않는 것으로 나타났다. 상관분석 결과 $BOD_5$는 $COD_{Mn}$, TOC의 상관계수가 0.890 (p<0.01), 0.721 (p<0.01)로 상관성이 통계적으로 높게 나타났다. 요인분석결과 경안천은 유기물 지표항목에 의한 요인이 가장 크며 계절변화에 따른 질소물질에 의한 요인, 유량증가에 따른 부유물질 유입요인 순으로 수질에 영향을 받고 있는 것으로 설명할 수 있다.

• 환경영향평가
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• 제28권3호
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• pp.215-230
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• 2019

본 연구는 한강 수계의 주요 지류 하천에 통계분석을 이용하여 수질특성을 파악하고 하천 등급화 방법에 따른 우선으로 관리되어야 할 지류 하천을 선정하여 수질 개선 방안을 제시하는 것이다. 한강 수계의 주요 15개 지류 하천을 대상으로 2017년 1월부터 12월까지 유량 및 수질을 모니터링 하였다. 상관 분석 결과 하천 유량은 수질 항목 간의 상관성(p>0.05)이 있지 않았으나 COD와 TOC는 통계적으로 유의한 수준의 높은 상관성을 나타냈다(r=0.957, p<0.01). 주성분 분석 결과 유기오염 물질 및 영양염류에 의한 오염이 수질변동의 주요한 요인으로 나타났으며 BOD, COD, TOC, TN, TP는 일원 분산분석 결과 계절별로 유의한 수준에서 차이가 있는 것으로 나타났다(p<0.05). 정량적 지표에 따른 하천 등급화 결과 수질개선이 필요한 지류 하천은 공공하수처리시설 방류수의 영향을 받는 굴포천, 안양천, 왕숙천, 탄천 등으로 나타났다. 본 연구를 통하여 한강 수계의 수질 개선이 필요한 지류 하천을 선정할 수 있었으며 효율적인 수질 관리를 위한 중요한 자료로 활용될 수 있을 것으로 판단된다.

• 한국물환경학회지
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• 제29권3호
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• pp.317-328
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• 2013

The purpose of this study was to investigate the change of phytoplankton fluctuation and long term of water quality of Lake Juam and to evaluate the relationship between phytoplankton pattern and environmental factors data. Correlation and factor analyses were employed to identify key environmental factors affecting phytoplankton dynamics. Of 18 parameters, pH, temperature, COD, BOD and T-P were highly correlated with Chl-a. Phytoplankton data showed that cyanobacteria were dominant, and more than 60% of total algae density. Also Lake Juam received a lot of influence of the Asian monsoon climate. This study presents necessity of multivariate statistic techniques for evaluation of Lake Juam complex data set with a view to get better information data and effective management of water source.

• 한국물환경학회지
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• 제21권3호
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• pp.274-276
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• 2005

To investigate bioassay for toxic level evaluation of wastewater, toxic levels were checked influents and effluents of 6 wastewater discharge facilities with Daphnia magna and Vibrio fischeri. In view of test duration, D. magna is preferred at 48 hours. And it was judged to efficient that one of the two was choosen for toxicity test method (Daphnia test and Vibrio test). Analysis data for wastewater is average toxic level for influent more higher than effluent. And effluent toxic level is sharp decrease than effluents.

• 한국물환경학회지
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• 제25권5호
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• pp.742-749
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• 2009

To examine the characteristics of the nutrient release from the sediments in two reservoirs, Lake Paldang and Lake Cheungpyeung, we analyzed physical and chemical properties of the sediments and calculated the nutrient release rates from the sediments. The particle properties of sediments in Lake Paldang changed from silt to sand after summer rainy season, especially in the water area of the Kyeungan River where the water depth was shallow and the width of river was narrow. The sediments in Lake Cheungpyeung had higher contents of silt and clay than in Lake Paldang, and the particle size was not much different before and after rainfall. The release rates of nutrients in two lakes varied with the kind of nutrients and the season. The release rates of DTN and ${NH_4}^+-N$ in Lake Paldang were faster in spring than autumn. But the Lake Cheungpyeung showed similar values of release rates before and after summer rainy season. ${NO_3}^--N$ and phosphorous were not released from sediments or were absorbed into sediments all the time in two lakes. Compared with other lakes, the sediments of two lakes consisted of bigger particles and had a lower organic matters content than other lake-type reservoirs. Due to the short hydraulic retention time and no stratification throughout the year in Lake Paldang and Lake Cheungpyeung, the release rates of nutrients from sediment in these reservoirs were lower than other lakes and this seems to be a typical characteristic of river-type reservoirs.

• 한국물환경학회지
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• 제24권6호
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• pp.750-757
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• 2008

This study is conducted to characterize and evaluate delivered pollutant loads of point and nonpoint source on the upper watershed of lake paldang. The study area consists of 12 watersheds in Namhan-river and Kyungahcheon, which are approximately 80% of total area of Namhan-river and Kyungahcheon. Based on daily delivered loads from watersheds, 61% of $BOD_5$, 81% of T-N and 70% of T-P were from nonpoint sources, suggesting that delivered loads of nonpoint pollutants be crucial to water quality. On the other hand, 78% of $BOD_5$, 92% of T-N and 87% of T-P as delivered load were from nonpoint sources in an upper watershed of Namhan-river, while 48% of $BOD_5$, 70% of T-N and 57% of T-P as delivered load were from nonpoint sources in a lower watershed of Namhan-river, suggesting higher dependency of point sources than upper watershed of Namhan-river. In the characteristic of delivered loading pollutants from point and nonpoint pollution sources, delivered load of nonpoint pollutants differed significantly by seasonal flow, and as though discharged load of point pollutants were yearly uniform, delivered load of point pollutants was found to be flow-dependent because its delivery ratio was changed.

• 한국환경과학회지
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• 제12권2호
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• pp.133-137
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• 2003

The Yellow River delta is an important region where coastal and newly formed wetlands distribute in north China. Based on satellite remote sensing images and GIS techniques, this paper tends to delineate the dynamic changes of newly formed wetland in the Yellow River mouth from 1986.5 to 1996.10. Our results show that the newly formed wetland increased by 24.9 $\textrm{km}^2$ per year. Before 1990. 1 and it decreased by 2.40 $\textrm{km}^2$ per year after that. The northern and southwestern parts of the Yellow River mouth are main positions of decrease and the southern and the estuary parts are main positions of increase. The advancing rate of river mouth extending into the Bo Sea is decreasing obviously. The reason for that is the decreasing of water and sediments in the Yellow River, which caused by the increasing use of water and soil conservation on upper reach.