• 한국물환경학회지
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• 제28권1호
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• pp.18-25
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• 2012

For effective watershed management, it is very important to select the tributaries through selection and concentration of targeted tributary catchments for improving water quality within the limited financial conditions. This study introduced the selection and diagnosis procedure of tributary catchments for improving water quality at Chungcheongnam-do based on water quality and flowrate monitoring, stream grouping method. The tributaries with high value of water quality and flowrate were selected for improving water quality according to stream grouping method. The diagnosis of selected tributaries for improving water quality was performed with analysis of the pollution load (generated, discharged, delivered) and point source discharged pollution load density. The plans for improving water quality of tributaries were suggested thorough various diagnosis of tributary catchments. For improving water quality of tributaries in Chungcheongnam-do, the tributary catchments in the Dangjin, Asan, Yesan, Cheonan, Hongseong area should be preferentially considered. The water quality improving plans for those tributary catchments, in accordance with the reduction of sources of pollution by population and livestock, should be established.

• 대한환경공학회지
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• 제39권11호
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• pp.641-649
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• 2017

본 연구에서는 오염원의 변화 특성이 다양한 임진강유역을 대상으로 통계분석을 이용하여 상관분석, 주성분 및 요인분석, 군집분석을 통해 수질특성을 파악하였다. 신천3 지점의 평균 수질농도가 BOD 13.4 mg/L, COD 19.9 mg/L, TN 11.145 mg/L, TP 0.336 mg/L, TOC 14.2 mg/L로 높게 나와 전체 유역 중 신천 유역에 대한 집중적인 수질관리가 필요한 것으로 나타났다. 전체 수질측정 자료의 상관분석 결과 COD는 TOC, BOD, TN 수질인자와 유의한 상관관계를 보여 유기물과 영양염류인자간의 상관성이 높은 것으로 나타났다. 주성분분석 결과 전체 측정소 자료는 81.221%로 2개의 주성분, 계절별 자료는 96.241%로 3개의 주성분이 추출되었다. 요인분석 결과 전체 측정소 자료와 계절별 자료의 수질영향 요인은 공통적으로 BOD, COD, TN, TP, TOC 항목이 나타났다. 시 공간적 군집분석 결과 계절별 특성 및 토지이용에 따라 각각 4개, 3개 그룹으로 나타났다. 본 연구는 임진강유역을 중심으로 8년간 시 공간적 특성을 고려한 수질 요인을 분석한 것으로 향후 유역환경변화에 따른 임진강 유역의 수질 변화를 이해하기 위한 기초 분석 자료가 될 것이다.

• 상하수도학회지
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• 제31권1호
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• pp.93-101
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• 2017

In this study, we investigated the correlation between the number of cyanobacterial species and the water quality factors after installation of Nakdong river weirs. Factor analyses of water quality factors were also performed. The results of correlations showed that there was no significant water quality with the cyanobacterial concentration but the correlation coefficient of nutrients increased from the upstream to the downstream. There was a significant correlation between W T and pH as important water quality factors for the growth of cyanobacteria. In the downstream region of Nakdong river, algae were more frequently detected than in the upstream region, and the blooms of algae species seem to be influenced by the higher pH and the influx of the phosphorus from the upstream tributaries. Nutrient concentration was higher in the downstream region than in the upstream region due to the effects of tributaries Geumho river and Nam river in Nakdong river. As a result of the factor analyses, nitrogen species were the principal factors in the upper region, and phorsphorus species were the principal factors in the downstream region.

• 한국물환경학회지
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• 제22권6호
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• pp.1144-1150
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• 2006

Recently, as water pollution accidents in rivers have increased, there is an increased interest in water quality forecast with accurate simulation. QUAL2E model, widely used for water quality analysis, uses the same hydraulic characteristics, such as depth and velocity, in a reach. The flow of the river is changed by various hydraulic constructions or by topography in a real river channel. In this study, a hydraulic connection module is developed to consider flow variations of river channels in QUAL2E model. The module uses the simulations results of non-uniform flow of a 1-D hydraulic model such as DWOPER or HEC-RAS. The improved QUAL2E model with this module was applied to a downstream section of Paldang Dam on the Han River. The results show the variation of water quality very well in a reach where flowing vary abruptly, like the Jamsil submerged weir.

• Mass Spectrometry Letters
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• 제11권4호
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• pp.90-94
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• 2020

Interest in aspects of industrialization relating to human health has increased. Accordingly, the use of labels such as 'natural foods' and 'organic ingredients' has become more widespread, and greater emphasis is being placed on improving quality of life. Water is an essential element for human life, and water quality has a significant impact on human health. However, technology that can precisely determine the substances present in water is still lacking. This study was conducted to establish a complete mass spectrometry process, from pretreatment to analysis, to measure and characterize natural organic matter (NOM) in Korean spring water samples. Salts and other matrices were removed from the samples using solid-phase extraction (SPE) with two different columns (PPL and C18). After establishing an accurate analysis method, the experimental results were evaluated based on Van Krevelen diagrams and analysis of molar O/C and H/C ratios. The method for characterizing NOM introduced herein should facilitate evaluation of water quality.

• 한국환경보건학회지
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• 제41권2호
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• pp.90-101
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• 2015

Objective: This study was conducted to develop a chemical oxygen demand (COD) regression model using water quality monitoring data (January, 2014) obtained from the Han River auto-monitoring stations. Methods: Surface water quality data at 198 sampling stations along the six major areas were assembled and analyzed to determine the spatial distribution and clustering of monitoring stations based on 18 WQPs and regression modeling using selected parameters. Statistical techniques, including combined genetic algorithm-multiple linear regression (GA-MLR), cluster analysis (CA) and principal component analysis (PCA) were used to build a COD model using water quality data. Results: A best GA-MLR model facilitated computing the WQPs for a 5-descriptor COD model with satisfactory statistical results ($r^2=92.64$,$Q{^2}_{LOO}=91.45$,$Q{^2}_{Ext}=88.17$). This approach includes variable selection of the WQPs in order to find the most important factors affecting water quality. Additionally, ordination techniques like PCA and CA were used to classify monitoring stations. The biplot based on the first two principal components (PCs) of the PCA model identified three distinct groups of stations, but also differs with respect to the correlation with WQPs, which enables better interpretation of the water quality characteristics at particular stations as of January 2014. Conclusion: This data analysis procedure appears to provide an efficient means of modelling water quality by interpreting and defining its most essential variables, such as TOC and BOD. The water parameters selected in a COD model as most important in contributing to environmental health and water pollution can be utilized for the application of water quality management strategies. At present, the river is under threat of anthropogenic disturbances during festival periods, especially at upstream areas.

• 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.

• 한국농공학회논문집
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• 제62권5호
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• pp.15-26
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• 2020

There are fifteen non-point pollution management areas in Korea and three of them (Doam lake, Daegi district and Golji-cheon) are located in the upstream of the Namhan river watershed. Many efforts to reduce non-point sources (NPS) pollution have been conducted, however, water quality pollution in the watershed is still serious. To solve these problems, it is a priority to grasp water quality using statistical techniques. In this study, a trend analysis was conducted to evaluate the effect of NPS management in the watershed. The long-term trends from 1996 to 2018 of water quality properties were analyzed using data collected from the water environment information system. Seventeen monitoring stations were selected along the main stream in Namhan river basin. Monthly water quality properties (BOD, COD, TN, TP, TN/TP ratio, Conductivity, SS and Chlorophyll-a) were collected and analyzed by Mann-Kendall test and LOWESS. The results showed that the Conductivity tended to increase in all regions and was the highest level in Jijangcheon. Organic pollution such as BOD and COD tended to increase in the Jungseon area. SS did not show a large tendency, but it showed high concentration in the Doam watershed. In all regions, 40% of water quality properties showed a tendency to 'UP', 15% of water quality properties tended to 'DOWN', and 46% indicated no tendency. In order to determine the cause of this, additional research and measures for improvement are necessary. This study will be used for the establishment of water quality policy in the future.

• 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.

• Current Research on Agriculture and Life Sciences
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• 제24권
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• pp.49-53
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• 2006

The objective of this study was to present regression equations between reservoir water quality and land use types of the watersheds. In order to derive regression equations, a multiple linear regression analysis was used using observed data from 88 reservoirs in the Kyungpook Provcince. The measured values of BOD, COD, T-N, and T-P were correlated with the areas of land use types. 23 regression equations were obtained for all the water quality items and watershed sizes. The results showed that 2 regression equations have the multiple correlation coefficient(MCC) above 0.90, 10 regression equations have the MCC values from 0.70 to 0.90, 9 equations have the MCC from 0.40 to 0.70, and 2 equations have the MCC from 0.20 to 0.40. The results of this study can be used to estimate reservoir water quality simply and quickly in the planning phase.