• Journal of Korean Society on Water Environment
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• v.30 no.2
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• pp.184-198
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• 2014

For estimating discharge and pollution loads into the Yeongsan lake, a conceptual watershed model HSPF(Hydrological Simulation Program - Fortran) was applied to the Yeongsan River Basin. Various spatial data set including DEM, watershed boundaries and land uses were used to set up the model for the Yeongsan River Basin that was divided into 45 sub-basins. The model was calibrated and validated for the river discharges, SS, BOD, TN and TP concentrations against the data observed in 2011 at several monitoring stations. The simulation results show good agreement with the observed water flows($R^2$ = 0.46 - 0.97, NSE = 0.70 - 0.96). The simulated concentrations of SS, BOD, TN and TP are also in good agreement with the observed. The total freshwater discharge to the Yeongsan lake is estimated $2,406{\times}10^6m^3/year$ which the Jiseok and Hwangryoung stream contribute as much as 19%, 17% respectively. It is estimated that the total discharges to the Youngsan lake is SS 152,327 ton/year, BOD 15,721 ton/year, TN 10,071 ton/year, TP 563 ton/year. Both water and pollution loads are high in summer, particularly in July, when the monsoon season arrives at the Korean peninsula.

• Journal of The Geomorphological Association of Korea
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• v.23 no.3
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• pp.57-66
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• 2016

The objective of this study is to find out geomorphological characteristics of historical ruins where people produced and consumed large jar coffins excavated in the Yeongsan river basin using the map of old drainage network to restore distribution network. For this purpose, we chose the 21 consumption sites. The results are as follows. First of all, large jar coffins(relics, 47.6% of total) in the Yeongsan River basin were located in Sampo stream basin, almost all of them were located within the Yeongsan River main stream basin and Sampo stream basin. Also, distance from all consumption site to river was within about 2km. Therefore, it is thought that the all consumption sites are located at the place of the gift of nature that was very favorable to water transport of jar coffins. The results of this study may be used as basic data for research of cultural relics in the Yeongsan river basin.

• Journal of Korean Society on Water Environment
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• v.33 no.2
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• pp.130-139
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• 2017

With the need to evaluate accuracy of real-time measurement of cyanobacterial fluorescence to determine cyanobacterial blooms, this research examined 357 paired data (2013-2016) comprising both microscopic toxic cyanobacterial cell counts and concurrent real-time cyanobacterial concentrations at 2 sites (YS1 and YS2) in Yeongsan river. The increase in real-time cyanobacterial concentration was closely associated with the exceedance of 5,000 cyanobacterial cells/ml (odds ratio [OR] 1.07, 95% confidence interval [CI] 1.03-1.12) and 10,000 cells/ml (OR 1.08, 95% CI 1.04-1.12) at YS2 site. The area under the receiver operating characteristic (ROC) curve for the real-time cyanobacterial measurement at the YS2 site was 0.93, which indicates the measurement provides a high accurate detection of cyanobacterial blooms. On the ROC curve, the early alert levels of real-time cyanobacteria ranging $16-23{\mu}g$ chl-a/L would produce acceptable sensitivity of 79% and specificities greater than 90%. The real-time fluorescence measurement was found to be an accurate indicator of cyanobacteria and can serve as a tool for detecting toxic cyanobacterial bloom events in Youngsan river.

• Journal of Environmental Impact Assessment
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• v.21 no.6
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• pp.917-925
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• 2012

In this study, we report the runoff characteristics of pollutants for Tamjin A and B watershed in Tamjin river basin using statistical analysis, such as correlation analysis and regression equation. Flow rate and water qualtiy data collected from 2 sampling sites(Tamjin A and B watershed) during 3 years(2009~2011) were analyzed for biochemical oxygen demand(BOD), total nitorgen(TN), total phosphorus(TP) and suspended solid(SS). The results showed that strong correlations were observed between flow rate and SS in Tamjin A, while weak correlations were observed among the BOD, TN, and TP. In Tamjin B, strong correlations were observed among the flow rate, SS and T-P except BOD and TP. Meanwhile, the values of $R^2$ for regression equations between flow rate and pollutants load were greater than 0.7. Results of these statistics indicated that there was a good agreement between flow rate and pollutants load. Also, the flow rate exponents of regression equations for BOD, TN, and TP were smaller than 1 in Tamjin A. In Tamjin B, flow rate exponents of regression equation for BOD and TP were smaller than 1. These results indicated that concentrations of BOD, TN, TP in Tamjin A and concentrations of BOD and TP were decreased as the flow rate was increased. This means that rater than nonpoint sources, point sources affect BOD, TN and TP in Tamjin A and BOD and TP in Tamjin B.

• Journal of Environmental Impact Assessment
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• v.23 no.3
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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.

• Journal of Environmental Impact Assessment
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• v.22 no.4
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• pp.319-327
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• 2013

This study was conducted to identify runoff characteristics of pollutants using flow duration curve(FDC) and load duration curve(LDC) in Youngbon A watershed during 2009~2011. A flow rate and pollutant load in the study watershed were estimated by equation of stage-discharge and discharge-loads rating curve. From these methods, BOD, T-N, and T-P have evaluated whether water quality standards would have attained. Results showed that BOD loads of about 50% plotted above the LDC, while T-N and T-P loads of about 50% plotted below the curve. It means that BOD of about 50% have exceeded the water quality criteria, while T-N and T-P of about 50% have complied with the water quality standards. Meanwhile, BOD, TN and T-P loads plotted above the LDC of low flows, implying that they were more affected by point pollution sources than nonpoint pollution sources in the study watershed.

• Korean Journal of Ecology and Environment
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• v.45 no.4
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• pp.412-419
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• 2012

This study assessed the impacts of land use types on water quality in the tributary of the Yeongsan river basin. Temporal changes in water quality parameters (BOD, COD, TOC, T-P, T-N, SS) were investigated. 13 water sampling sites were selected; they were then collected and analyzed according to the standard method. The results showed that water quality parameters of the study sites ranged as follows : BOD, from 0.3 to $21.9mg\;L^{-1}$ (mean $3.3mg\;L^{-1}$); COD, from 1.0 to $38.0mg\;L^{-1}$ ($6.4mg\;L^{-1}$); TOC, from 0.6 to $20.0mg\;L^{-1}$ ($4.5mg\;L^{-1}$); T-P, from 0.009 to $1.973mg\;L^{-1}$ ($0.144mg\;L^{-1}$); T-N, from 0.6 to $17.1mg\;L^{-1}$ (mean $3.5mg\;L^{-1}$); SS, from 0.3 to $292.0mg\;L^{-1}$ ($20.3mg\;L^{-1}$). Generally, the paddy and upland dominated region had high concentrations of water quality parameters, whereas the forest dominated region had low concentrations. In addition, water quality parameters were positively correlated with paddy and upland, whereas the parameters were negatively correlated with forest. The result implies that paddy and upland are the dominant factors leading to stream pollution in the study sites, while a higher percentage of forest area contributes to improved water quality. Therefore, it is important to manage paddy and upland in order achieve efficient management of water quality.

• Journal of Environmental Impact Assessment
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• v.22 no.2
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• pp.171-181
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• 2013

In this study, we report the water quality characteristics of pollutants for 4 major tributaries in the Yeongsan and Sumjin river basins using statistical analysis, such as regression equation and factor analysis. The flow rate and water qualtiy data collected from 4 sampling sites(Hwangryoung A, Jiseok A, Chooryeong A, Osu A) in the Yeonsan and Sumjin river basin during the past 3 years were analyzed for 11 parameters(flow rate, dissolved oxgen, pH, water temperature, electric conductivity, biochemical oxygen demand, chemical oxygen deman, total organic carbon, total nitorgen, total phosphorus, suspended solid). The results showed that the concentrations of BOD, COD, TOC, T-N, T-P in Hwangryoung A(HW) and Jiseok A(JS) of the Yeongsan river basin were decreased as the flow rate was increased. This means that rather than nonpoint soources, point sources affect water quality. In the cases of Chooryeong A(CR) and Osu A(OS) in the Sumjin river basin, howerever, nonpoint sources than point sources are an important factor that affects the water quality. Also, the factor analysis technique was employed to analyze principal component influencing on water quality. The results revealed that the first principal component in HW was correlated with EC, DO, T-N, water temperature. This "nitrogen influx according to seasonal pattern" factor may be interpreted. In JS, the first principal component was correlated with BOD, COD, TOC and is likely to represent "organic matter" processes. In CR and OS, BOD, COD, TOC, SS and T-P were significantly correlated and is considered as representing "Organic matter and adsorption of phosphorus on sediments influx". This study is expected to contribute to the effective pollution control/management of the surfac waters in the study sites.

• Korean Journal of Ecology and Environment
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• v.44 no.4
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• pp.358-363
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• 2011

This study investigated the characteristics of natural organic matter(NOM) with tXAD resin and FT-IR in the Yeongsan river system of Gwangju region. NOM fractionation by XAD 8/4 resins was used to classify hydrophobic and hydrophilic substances. FTIR was applied to classify functional groups in the structure of NOM. In the XAD investigation, most of the four site-samples were mainly hydrophilic substances. In March, hydrophobic substances were dominant in the Gwangju 1 site (GJ-1), while hydrophilic substances were dominant for the other sites. In May, samples of all four sites were hydrophilic with a vigorous activity of microorganism due to increasing temperatures. The October results were very similar with those from March. In the FT-IR investigation, most of the broad and large peaks were assigned to the aliphatic group, particularly the OH group, C-H, $C-H_2$, $C-H_3$, and C-O alcohol group. All were related to hydrophilic substances. Other peaks showed the aromatic group, particularly the C=O (Ketone) Group. As a result, there is an identification of NOM in the Yeongsan river system composing mainly of hydrophilic substances and functional groups (OH, C-H etc.) of the aliphatic compound.

• Korean Journal of Ecology and Environment
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• v.40 no.3
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• pp.419-430
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• 2007

Physiochemical factors, phytoplankton biomass (Chl ${\alpha}$) and primary productivity were investigated seasonally in the three lakes of Dongbok, Juam, and Yeongsan during April 2004${\sim}$March 2006. Microphytoplankton dominated (>60%) in Dongbok lake, and phytoplankton biomass was high in the upper area, especially during April 2004, whereas they were high in the lower area during June 2004. In Juam lake, the high phytoplankton biomass in April 2004 was contributed by nanophytoplankton. In Yeongsan lake, chlorophyll a was high in August with high contribution of nanophytoplankton. Primary production was highest in Dongbok lake, and then followed by Yeongsan and Juam lakes. Regression analysis in Dongbok take showed that Chl ${\alpha}$ and primary production had close relations with secchi depth. In Juam lake, phosphate were correlated with the Chl ${\alpha}$, while temperature and TN was correlated with primary production in the lower area. In Yeongsan lake, Chl ${\alpha}$ have positively correlation with TN/TP. Primary production in the upper have high relationship with secchi depth, however, in the lower have high relationship with turbidity. Linear regression analysis showed that nutrients of nitrogen and phosphorus should be reduced for the protections in Juam and Dongbok lakes. We suggested that suspended solids and phytoplankton growth related to turbidity are needed to manage in Yeongsan lake.