• 한국환경과학회지
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• 제25권6호
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• pp.767-787
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• 2016

In this study, we analyzed on-site monitoring data for 15 tributaries in Geumho watersheds for 3 years (2011-2013) in order to sort out priorities on water quality characteristics and improvement. As a result of estimating contribution to contamination of the tributary rivers, Dalseocheon showed the highest load densities, despite the smallest watershed area, with 22.7% $BOD_5$, 30.7% $COD_{Mn}$, 31.3% TOC and 47.6% TP. After conducting PCA (principal component analysis) and FA (factor analysis) to analyze water quality characteristics of the tributary rivers, the first factor was classified as $COD_{Mn}$, TOC, EC, TP and $BOD_5$, the second factor as pH, Chl-a and DO, the third factor as water temperature and TN, and the fourth factor as SS and surface flow. In addition, arithmetical sum of each factor's scores based on grading criteria revealed that Dalseocheon and Namcheon were classified into Group A for their highest scores - 96 and 93, respectively -, and selected as rivers that require water environmental management measures the most. Also, water environmental contamination inspection showed that Palgeocheon had the most number of aquatic factors to be controlled: $BOD_5$, $COD_{Mn}$, SS, TOC, T-P, Chl-a, etc.

• 농업생명과학연구
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• 제52권6호
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• pp.89-101
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• 2018

본 연구는 4대강 사업에 따른 낙동강 수질의 변동성을 평가하기 위한 것으로, 낙동강에 건설된 8개보 건설 전후의 수질을 비교, 분석하였다. 이를 위해 보에서 가장 인접한 상류 수질측정지점을 대상으로 4대강 사업전(2003년 1월부터 2008년 11월), 사업중(2008년 9월부터 2012년 4월), 사업후(2012년 5월부터 2017년 9월)까지의 3개 기간에 대해 DO, BOD, COD, SS, T-N, T-P, TOC 등의 수질자료를 수집하였다. 4대강 사업전후 자료의 유의성 검증을 위해 대응검정 T-test를 95%의 신뢰구간에서 실시한 결과 DO, BOD, COD, T-N, TOC는 사업 전보다 사업 후 수질 농도가 높아지는 경향이 있으며, 그 중 BOD, COD, TOC의 농도가 큰 차이를 보였다. 반면에 SS, T-P는 사업 전보다 사업 후 농도값이 감소하였다. 수질인자 중 변화값이 큰 BOD, COD, TOC를 수질등급으로 나누어 공간적으로 분석해 본 결과 사업전에 비해 사업후의 수질등급이 나빠지는 경향을 보였다.

• 한국물환경학회지
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• 제33권6호
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• pp.640-649
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• 2017

The purpose of this study is the analysis of the water quality spatial characteristics for the main stream of Nakdong River in consideration of the tributary inflow. The flow and water quality (BOD, TOC, TP) data for 32 monitoring stations located in the main stream and the tributaries of Nakdong River were collected from 2003 to 2016. From the results of the flow and water quality analyses for each site, a status map of the flow and the water quality for Nakdong River was produced. The water quality of each river section was classified according to seven river-environment standards. The water quality changes in the main stream before and after the confluence were analyzed spatially. As a result, the water quality of Kumho River, in particular the Kumho B to Kumho C section, is the worst among the tributaries. In addition, the water quality grades of the lower streams such as Nam River and Miryang are worse than that of the upper streams of the Nakdong River. In the case of the main stream, the water quality grades of the sections between the Wicheon and Nam River confluences and the section from Nakbon L to Nakbon N are relatively poor.

• 물과 미래
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• 제17권2호
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• pp.85-97
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• 1984

Measuring the river flow and water quality in the midstream of the Nakdong River, the natural purification status in examined through the analyses of the elements which affect the variation of dissolved oxygen, and DO model is evaluated to the midstream reach of the river. The major results of this study are as follows; the pruification factor of the of the river is relatively high, it is worried over eutrophication considering much production of algae, and it is evaluated that important factor affecting the DO value computed by the proposed DO model are in order of reaeration coefficient, carbonaceous BOD and deoxygenation constant.

• 한국물환경학회지
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• 제33권1호
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• pp.40-50
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• 2017

We were interested in the long-term temporal and spatial variability trends of water quality. Trend tests such as the Seasonal and Regional Kendall tests and LOWESS (LOcally WEighted Scatter plot Smoother) have been recommended as outstanding tools for trend detection. In this study, we conducted four types of nonparametric trend tests (Seasonal and Regional Kendall tests, LOWESS, and flow-adjusted Seasonal Kendall). We aimed to identify water quality trends using the monthly data for five variables (BOD, COD, TN, TP, and flow) collected from 24 sites in the Nakdong River from August 2004 to December 2013. According to the Regional Kendall test, BOD, COD, and TN increased but TP decreased trend. The Seasonal Kendall test showed that BOD, TN, and TP remained constant at 62.5-83.3% of the sites. COD remained constant at 58.3% of the sites. LOWESS showed that TP gradually increased between 2007 and 2008, then decreased slowly at the Gumi, Geumhogang6, Daeam-1 and Milyanggang3 sites. BOD increased slightly between 2008 and 2009, and then decreased slowly at the Namgang4-1 site. Lastly, a flow-adjusted Seasonal Kendall test was conducted. There were different results between Seasonal Kendall and flow-adjusted Seasonal Kendall tests at 11 of the 24 sites. According to the results from six of the eleven sites, BOD increased at one site, showed no trends at three sited, and decreased at two sites. Each of COD, TN increased at two, one site. but TP decreased at two sites.

• 한국환경과학회지
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• 제25권11호
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• pp.1499-1509
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• 2016

This study was performed to analyze the effects of a water circulation green area plan on non-point source pollution in Gimhae South Korea. A quantitative analysis of Arc-GIS data was conducted by applying a watershed model based on Fortran to investigate the changes to direct runoff and pollution load. Results showed that prior to the implementation of the water circulation green area plan in Gimhae, direct runoff was $444.05m^3/year$, total biological oxygen demand (BOD) pollution load was 21,696 kg/year, and total phosphorus (TP) pollution load was 1,743 kg/year. Implementation of the development plan was found to reduce direct runoff by 2.27%, BOD pollution load by 1.16% and TP pollution load by 0.19% annually. The reduction in direct runoff and non-point source pollution were attributed to improvements in the design of impermeable layers within the city.

• 한국환경과학회지
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• 제20권8호
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• pp.977-986
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• 2011

This study analyzed the characteristics of stormwater runoff in the orchard areas and quantitatively estimated effluence of nonpoint source pollutants for the volume of runoff. Two target areas under vine cultivation were each $2,000m^2$ and $1,800m^2$, located in Gyeongju City. Since grape was the only crop on the target area, the characteristics of stormwater runoff at vineyard could be evaluated independently. A total of 51 rainfall events in the vineyard area during two years(2008-2009) was surveyed, and 19 of them became stormwater runoff, with rainfall ranging 16.5 - 79.7 mm and antecedent dry period of 1-13 days. The pollutant runoff loads by volume of stormwater runoff showed BOD ranging 19.5 - 45.3% in 30% of runoff volume. The average pollution discharge rate was 32.4%, indicating small first flush effect of BOD. The range of SS concentrations was 5 - 52.0% in 10% of runoff volume, showing the average 28.7% of discharge rate, about 3 times more than rainfall effluent. TOC and TN appeared to be similar to the results of BOD, the average discharge rate of 30.9% and 30.6% for TOC and TN, respectively, for 30% of stormwater runoff volume. Average discharge rate of COD and TP in the same runoff volume was 35.1% and 36%, respectively, showing comparatively high discharge ratio. As the targeted vineyard area was permeable land, the pollution load ratio against rainfall-runoff volume appeared to be 1:1, implying no strong first flush effect for all the survey items.

• 환경영향평가
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• 제21권4호
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• pp.543-552
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• 2012

Namgang mid-watershed is located in downstream of Nakdong river basin. There are many pollution sources arround this area and it's control is important to manage a water quality of Nakdong river. A target year of Namgang mid-watershed water environment management plan is 2013. To predict a water quality at downstream of Namgang, we have investigated and forecasted the pollutant source and it's loading. There are some plan to construction the sewage treatment plants to improve the water quality of Nam river. Those are considered on predicting water quality. As results, it is shown that the population is 343,326 and sewerage supply rate is 79.2% and the livestock is 1,662,000 in Namgang mid-watershed. It is estimated that the population is 333,980, the sewerage supply rate is 86.9% in 2013. The milk cow and cattle were estimated upward and the pigs were downward by 2013. The generated loading of BOD and TP is 75,957 kg/day and 4,311 kg/day, discharged loading is 18,481 kg/day and 988 kg/day respectively in 2006. It were predicted upward the discharged loading of BOD and TP by 4.08% and 6.3% respectively. The results of water quality prediction of Namgang4 site were 2.5 mg/L of BOD and 0.120 mg/L of TP in 2013. It is over the target water quality at that site in 2015 about 25.0% and 9.1% respectively. Consequently, there need another counterplan to reduce the pollutants in that mid-watershed.

• 한국습지학회지
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• 제24권4호
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• pp.301-311
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• 2022

본 연구는 장기 수질모니터링 자료를 이용하여 수질의 계절적 특성을 분석하는 것이 목적이다. 낙동강수계에서 장기 모니터링이 수행되고 있는 34개 지류에서의 모니터링 자료를 이용하여 수질의 계절적 특성을 분석하였고 계절적 분석을 위해 수질의 평균 자료 분석과 변동계수(Coefficient of variation) 분석, 추세분석을 수행하였다. 변동계수 평가결과, 지류가 본류보다 크고 계절적으로는 BOD와 T-P, TOC는 가을철이 크고 T-N은 봄철이 크게 나타났다. 추세분석은 Mann-Kendall과 Sen's Slope를 통해 분석하였으며 BOD와 T-N, T-P는 감소 경향이 많으나 TOC는 증가 경향이 많았다. 또한, 공간적으로는 낙동강 상류보다 하류에서의 증가하는 경향이 많이 나타났다. 본 연구를 통해 장기 수질모니터링 자료의 활용성 평가 및 계절적 특성을 분석할 수 있었고 유역관리를 위해 수질의 안정화 시기, 오염원 증감 변화를 분석할 수 있었다.

• 한국환경과학회지
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• 제20권3호
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• pp.361-372
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• 2011

This study analyzed the characteristics of stormwater runoff by rainfall type in orchard areas for two years. Effluents were monitored to calculate the EMCs and runoff loads of each pollutant. The runoff characteristics for nonpoint sources from vineyards were also inspected based on independent variables that affect runoff such as rainfall and rainfall intensity. The average runoff loads of each pollutant from vineyard_A and vineyard_B were found as follows: BOD 39.13 mg/$m^2$, COD 112.13 mg/$m^2$, TOC 54.98 mg/$m^2$, SS 1,681.8 mg/$m^2$, TN 18.29 mg/$m^2$, and TP 4.06 mg/$m^2$, which indicates that the COD's runoff load was especially high. The average EMCs from vineyard_A and vineyard_B, which represents the quality of rainfall effluent, were also analyzed: BOD 3.5 mg/L, COD 11.5 mg/L, TOC 5.2 mg/L, SS 211.7 mg/L, TN 1.774 mg/L, and TP 0.324 mg/L. This suggested that the COD, as an indicator of organic pollutants, is high in terms of EMCs as well. As rainfall increased, the EMCs of BOD, COD, TOC and SS kept turning upward. At a point, however, the high rainfall brought about dilution effects and began to push down the EMCs. Higher rainfall intensities led to the increase in the EMCs that displays the convergence of rainfall. Low rainfall intensities also raised pollutant concentrations, although the concentrations themselves were slightly different among pollutants.