• Journal of Wetlands Research
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• v.18 no.3
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• pp.301-312
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• 2016

This study has performed comparative analysis on characteristics of contaminated 35 tributaries on seasonal variation/point discharge load/pollutant distribution of water quality factors(8) in order to understand the effect of the watershed in Nakdong River Basin. As a results, the water quality of $BOD_5$(Biochemical Oxygen Demand), Chl-a(Chlorophyll a) and Fecal E. Coli shows II grade at tributaries of more than 50% without COD(Chemical Oxygen Demand), TP(Total Phosphate), TOC(Total Oxygen Carbon) and TN(Total Nitrogen) factors. The specific discharge(Q) were occupied about 54.4% (19 sites) as $0.05m^3/sec/km^2$ value. Among these results, the contaminant level of Dalseocheon, Hyeonjicheon, Seokkyocheon 1, Uriyeongcheon and Dasancheon was also high, which has to consider a discharged pollutant load(kg/day). The 35 major tributaries of Nakdong River were included in 7 mid-watershed, such as Nakdong Waegwan, Geumho River, Nakdong Goryung, Nakdong Changnyung, Nam River, Nakdong Milyang, Nakdong River Hagueon. Especially, the discharged pollutant load of Nam River and Geumho River also was high according to the amount of discharge such as Kachang dam, Gongsan dam and Nam river dam. Seasonal difference of the water quality factors such as $BOD_5$, TN, SS and Q was observed largely, on the other hand the TP and Chl-a was not. This is guessed due to the precipitation effect of site, biological and physicochemical degradation properties of pollutant and etc. The co-relationship between the seasonal difference and water quality factors was observed using a Pearson correlation coefficients. Besides, the Multiple Regression analysis using a Stepwise Regression method was conducted to understand the effect between seasonal difference and water quality factors/regression equations. As a result, the Multiple Regression analysis was adapted in the spring, summer and autumn without the winter, which was observed high at spring, summer and autumn in the order COD/TP, Chl-a/TOC, TOC/COD/$BOD_5$ water quality factors, respectively.

• The Journal of Engineering Geology
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• v.16 no.4 s.50
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• pp.373-379
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• 2006

We investigated the relationship of the organic pollutant index in wastewater where the high percentages of an organic load to a water body was found. Measuring of TOC was to identify the relationship with COD and BOD which were used already. The correlation coefficient (r) of TOC/COD, BOD/COD and TOC/BOD were effected by the types of industry such as paper, textile, chemical, food and metal industries. In food industry it was found that the highest correlation coefficient (r) of TOC/COD, BOD/COD and TOC/BOD as 0.967, 0.969 and 0.990, respectively. There is low correlation coefficient in many cases. Hence it was impossible that the use of TOC for the water standard or monitoring instead of COD and BOD directly. However it can be used as alternative index to management a water process in the case of waste water where there was found high correlation coefficient of TOC/ COD, BOD/COD and TOC/BOD. It was sure that the water quality of river body can be protected if we use these the relationship among organic index.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.145-145
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• 2023

육지의 영양염류는 강수를 통해 강을 따라 바다로 흐른다. 연안 수질과 생태계를 효과적으로 관리하기 위해 수계를 통해 연안으로 배출되는 육상 영양염류 유출의 변화를 연구하는 것이 중요하다. 그러나 제한적인 수량과 수질 동시 관측자료로 인해 한반도 연안으로 유입되는 영양염량 변화에 대한 연구는 매우 제한적이다. 따라서 본 연구에서는 한반도 내륙에서 주변 연안 지역으로 유출되는 영양염류의 유출량과 그 변화량을 추정 및 분석하고 유출량에 대한 수량과 수질 변화의 기여도를 정량적으로 조사하였다. 2012-2021년 봄철(3-5월)에 한반도 연안 주변의 75개의 하천 지점에서 측정된 수질 농도 및 유량 관측 데이터와 한반도 연안 375지점에서 측정된 해양 수질 농도 데이터를 사용하였다. 더불어 22개의 해안지역 하천 유량 관측소와 근접한 수질 관측자료를 통해, 총 질소(TN), 총 인(TP), 클로로필a의 봄철 영양염류 유출 총량을 추정하고 그 변화량을 평가하였다. 그리고 영양염류 유출 변화량을 모델 수식으로 분해하여 유출 총량 변화량에 대한 하천 유량과 영양염류 농도 변화의 상대적인 기여도를 분석하였다. 분석결과는 연간 봄철 TN, TP, 클로로필a 유출 총량의 변화율이 영양염류의 농도 (각각 19%, 48%, 5%)보다는 하천 유량 (각각 84%, 51%, 91%)에서 더 많은 영향을 받았음을 보여주었다. 한반도 연안을 서해, 남해, 동해로 나누어 영양염류 유출 총량을 분석한 결과, 한반도 전체 유출량에서 서해의 가장 큰 기여도를 확인하였다. 또한 한반도 내륙에서 유출된 영양염류 총량이 연안의 수질에 끼치는 영향을 조사하고자 내륙 하천과 연안의 수질 간의 상관관계를 조사하여 간접적으로 파악하였다. 본 연구는 분석적인 접근을 통해 하천과 연안 수질 환경에서 수문학적인 연결고리의 중요성을 강조하고, 영양염류 유출 변화가 해안에 서식하는 생태계와 양식산업 생산성에 미치는 잠재적인 영향을 강조하였다.

• Korean Journal of Environmental Agriculture
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• v.27 no.1
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• pp.1-9
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• 2008

The main purpose of this study is to accumulate the fundamental data representing groundwater of plastic film houses by means of water quality and its multivariate statistical analysis. Groundwater samples were collected in every two years since 2000 to 2004 from total 211 sites. According to the result of water quality analysis, ground water quality was suitable for irrigation purpose averagely. Correlation analysis showed that EC was highest positively correlated with $Mg^{2+}$ to 0.810(p<0.01), 0.776(p<0.01) in April and July, respectively. $NO_3-N$ was highest positively correlated with T-N to 0.794(p<0.01) in October. This result shows that it can lead to a different result even in similar case sometimes. Four factors were extracted through factor analysis in April and July, but five factors were extracted in October. The proportions of cumulative variance by the factor were 64.9, 60.2, and 70.7 in April, July, and October, respectively. The first factor was highly related to anions and cations such as $Ca^{2+},\;Mg^{2+},\;Cl^-,\;{SO_4}^{2-}$, and EC in contrast to that of stream water. According to the cluster analysis, 211 sites are classified into four groups. Common type of ground water quality was shown in group A. The pH and $PO_4-P$ were highest in Group B. The anions and cations were highest in Group C. $COD_{Cr}$ was highest in Group D.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.4C
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• pp.401-410
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• 2007

In this paper, we propose water quality monitoring system using vision camera and multiple objects tracking method. The proposed system analyzes object individually using vision camera unlike monitoring system using sensor method. The system using vision camera consists of individual object segmentation part and objects tracking part based on interrelation between successive frames. For real-time processing, we make background image using non-parametric estimation and extract objects using background image. If we use non-parametric estimation, objects extraction method can reduce large amount of computation complexity, as well as extract objects more effectively. Multiple objects tracking method predicts next motion using moving direction, velocity and acceleration of individual object then carries out tracking based on the predicted motion. And we apply exception handling algorithms to improve tracking performance. From experiment results under various conditions, it shows that the proposed system can be available for real-time water quality monitoring system since it has very short processing time and correct multiple objects tracking.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.6
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• pp.421-429
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• 2012

This study was aimed to analyze the water quality characteristics of the Hwapocheon Stream and to be utilized in the further related research. Water in the upper stream became a dammed pool due to the existence of 14 weirs, and pollutants such as both sewage and irrigation water were introduced into the mainstream passing through farming settlements and agricultural land. For these reasons, filamentous cyanobacteria (Oscillatoria sp.) bloomed at the bottom of the dammed pool. Also in the midstream and downstream, tributaries with high pollutant concentrations [e.g., Comocheon (T3) and Yongdeokcheon (T8)] were inflowed, and had a negative impact on water quality of the mainstream, especially nitrogen and phosphorus. In the Hwapocheon Stream, dissolved oxygen (DO) decreased, and suspended solid (SS) increased toward the downstream. The result showed that hydraulic retention time, SS, COD, and concentration of $NH_4{^+}$ were important water quality factors of the Hwapocheon Stream. The high concentration of benthic organic matter and rich in attached algae in the core of Hwapo-wetland were expected to give impact on the water quality of the mainstream. In the spatial manner, water quality showed increasing trend in the weir zone, and it was constant or decreased trend in wetland. In the seasonal manner, the nutrient concentrations were high in the winter dry season, however, the organic matter concentrations were high in spring and summer. Generally, the concentrations of phytoplankton value were $40{\mu}g\;chl-{\alpha}/L$ or less in all reaches except for the high concentrations in the weir and wetland area in June.

• The Journal of Engineering Geology
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• v.17 no.3
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• pp.445-453
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• 2007

The purposes of this study lie on understanding characteristic water-rock interaction mechanisms of groundwater in the Geochang, Hapcheon, and Changryeong areas and establishing correlation between geological factors and groundwater chemistry by statistical tools. Based on the statistical results from the relationship between rock types and groundwater chemistry, fluorine is correlated with Fe and Al in the diorite area, whereas it is correlated with Cl and $NO_3-N$ in the andesite area. Hardness, total solids, and $SO_4$ show that they are closely related to each other in all rock types, especially with highest relationship in sedimentary rocks. Although it is generally acknowledged that TDS increases with depths of aquifer due to the long term water-rock interaction, no remarkable relationship between well depth and water chemistry is found in this study. It appears that hydrogeological system in the study area may be complex or the path of water-rock interaction is inconsistent with well depth.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.201-201
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• 2023

일반적으로 하천의 수질은 산업화, 인구증가 등으로 인해 여러 종류의 오염물질이 유입되어 악화된다. 수질 악화의 대표적인 현상은 부영양화이며 이를 일으키는 주요 원인 물질은 통상 영양염류라고 말하는 질소와 인으로 알려져 있다. T-N이 다량 수계로 유입되면 식물성 플랑크톤 등이 대량 번식하여 녹조 현상등 수질 악화를 발생시켜 관리가 필요하다. 현재 많은 수자원 관리 부서에서 모니터링 포인트를 설정하여 수질 변화를 관찰하고 있다. 기존의 T-N 분석방법은 (1) 자외선 흡광광도법 (2) 카드뮴 환원법 (3) 환원증류-킬달법등이 있다. 그러나 이러한 방법들은 실험실 기반의 정량적 분석으로 시간과 비용이 크게 소요되어 발생하는 문제에 대해 초기대응을 하기 힘들다. 따라서 T-N을 효과적으로 측정할 수 있는 방법이 필요하다. 국내에서는 수질자료를 통한 연관된 수질 인자를 찾아내어 머신러닝 알고리즘을 활용해 Chl-a 농도를 추정한 연구사례가 있다. 국외에서는 TN과 센서 측정 지표 간의 물리적, 화학적 관계를 기반으로 센서 감지의 적시성과 지능형 알고리즘의 정확도를 결합하여 실시간 총질소(TN) 측정 방법 연구 사례가 있다. 따라서 본 연구에서는 머신러닝을 활용하여 국내에 적합한 T-N 예측 모델을 만들고자한다. 본 연구에서는 센서기반으로 측정가능한 수질항목들과 T-N의 상관성 분석을 통해 주요 수질인자를 도출하였다. 도출된 인자와 Python 기반의 머신러닝을 활용하여 T-N을 추정하였다. 그 후, T-N 추정값과 실측값을 비교하여 머신러닝 성능을 평가하고 실제 적용 가능성에 대해서 검증하였다. 본 연구는 기존 T-N 측정에 소모되는 시간과 비용의 감소에 기여하고 이를 통해 앞으로 더 정확한 수질 예측이 가능해질 것으로 기대된다.

• Korean Journal of Remote Sensing
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• v.37 no.6_2
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• pp.1859-1867
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• 2021

This study investigated seasonal characteristics of the particulate matter (PM) in the atmosphere and rainwater quality in Busan, South Korea, and evaluated the seasonal effect of PM₁₀ concentration in the atmosphere on the rainwater quality using multivariate statistical analysis. The concentration of PM in the atmosphere and meteorological observations(daily precipitation amount and rainfall intensity) are obtained from automatic weather systems (AWS) by the Korea Meteorological Administration (KMA) from March 2020 to August 2020. Rainwater samples (n = 216, 13 rain events) were continuously collected from the beginning of the precipitation using the rainwater collecting device at Pukyong National University. The samples were analyzed for pH, EC (electrical conductivity), water-soluble cations(Na⁺, Mg²⁺, K⁺, Ca²⁺, and NH₄⁺), and anions(Cl^-, NO₃^-, and SO₄^2-). The concentration of PM₁₀ in the atmosphere was steadily measured before and after the precipitation with a custom-built PM sensor node. The measured data were analyzed using principal component analysis (PCA) and Pearson correlation analysis to identify relationships between the concentration of PM₁₀ in the atmosphere and rainwater quality. In spring, the daily average concentration of PM₁₀ (34.11 ㎍/m³) and PM_2.5 (19.23 ㎍/m³) in the atmosphere were relatively high, while the value of daily precipitation amount and rainfall intensity were relatively low. In addition, the concentration of PM₁₀ in the atmosphere showed a significant positive correlation with the concentration of water-soluble ions (r = 0.99) and EC (r = 0.95) and a negative correlation with the pH (r = -0.84) of rainwater samples. In summer, the daily average concentration of PM₁₀ (27.79 ㎍/m³) and PM_2.5 (17.41 ㎍/m³) in the atmosphere were relatively low, and the maximum rainfall intensity was 81.6 mm/h, recording a large amount of rain for a long time. The results indicated that there was no statistically significant correlation between the concentration of PM₁₀ in the atmosphere and rainwater quality in summer.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.3
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• pp.457-464
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• 2017

The large breeding of algae in rivers has caused the algal bloom and has becoming a serious national problem for the safety of water sources. Therefore, in order to supply stable water resources through securing clean water, it is necessary to develop technology for prevention of water pollution caused by algal bloom. The purpose of this study is to improve the water quality management ability of river by applying the algal bloom detection technique using UAV. Unmanned aerial images were acquired for the Dodong in the middle region of the Nakdong River where algal bloom are frequent. In addition, the phytoplankton concentration was acquired through the sampling of algal bloom and the examination of water quality. Correlation between phytoplankton concentrations and the results of applying the algal bloom index to the Unmanned aerial images showed a strong positive correlation. The remote sensing method suggested in this study is expected to improve the initial response capability of river water pollution.