• Journal of Wetlands Research
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• v.18 no.4
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• pp.363-377
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• 2016

This study was investigated the pollutant load, contamination properties, pollution condition of the fine parts of tributary, the influence of Nakdong river watershed and etc. in the tributaries. The contaminated tributaries were that among the Kumho and Nam river or were too far from site of water quality monitoring stations, regularly. As a result, the water quality level was almost similar between Nam and Kumho River, except for certain parameter including TN(Total Nitrogen), Chl-a(Chlorophyll-a) and SS(Suspended Solid) in which Kumho river were 20~120%. The point discharge load(kg/day) and load density ($kg/day/km^2$) of tributaries were different the pollution level according to the flow-rate ($m^3/sec$) and stream influence area($km^2$), and the difference of these was observed highly at Nam river. Specific contamination investigation of tributaries in Nam and Kumho river watershed was conducted from two to nine points of the fine parts of tributaries depending on the confluence sites and shapes. This result observed high at the Dalseocheon and Uriyeongcheon, respectively. Beside, the pollutant load contribution rate of Nakdong watershed was high about 10% at the Dalseocheon and Uiryeongcheon. This was due to the differences of the environments about the industrial complex, metropolis residence property, agricultural cultivation, livestock pen and the downstream of non-point source.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.4
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• pp.19-26
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• 2010

To provide the basic information for the water quality management of the Sumjin River Basin, delivery ratios for flow duration were studied. Using the day-interval data set of discharge and water quality observed from the Chooryeong-cheon watershed, the flow-duration and discharge-load relation curves for the watershed were established, then the load-duration curve was constructed. Delivery ratios for flow duration were also developed. Delivery ratios showed wide variation according to flow conditions. In general, delivery ratio of high flow condition showed higher value reflecting nonpoint source pollution contribution from the forest dominating watershed. To resolve this problem, a regression model explaining the relation between flow rate and delivery ratio was suggested. The delivery ratios for different flow regime could be used for pollutant load estimation and TMDL (Total maximum daily load) development.

• Journal of Wetlands Research
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• v.19 no.3
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• pp.279-286
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• 2017

In this study, the characteristics of non-point source pollution runoff and the possibility of using new unit load were investigated by using pollutant load based on monitoring data considering baseflow. For this purpose, the components of hydrograph were separated by using digital filter method and the numerical integration method was applied to calculate the non-point source pollutant load for nine rainfall events in Juwon river in the Geum River basin. As a result of this study, the mean contribution rate of non-point pollutant was 31.34% for BOD, 58.94% for T-N, and 50.42% for T-P and BOD was more influenced by baseflow pollutant. Also, it was analyzed the pollutant load using the new unit load is closer to the observation load than the old unit load. This result implies that it is necessary to manage not only pollutant load due to direct runoff but also pollutant load due to baseflow runoff for efficient water quality management of the watershed.

• Journal of Korean Society on Water Environment
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• v.35 no.1
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• pp.43-54
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• 2019

The objective of this study was to assess the effect of policies on water quality management based on the changes in pollutants and water quality in Special Water Preservation Area (SWPA) of Lake Paldang watershed from 1990 to 2016. The population, total sewage and flow rate of wastewater in SWPA continuously increased from 1990 to 2016, while the location of new facilities for industrial and livestock facilities has been restricted. However, unlike the buffer zone in which industrial and livestock facilities were continuously reduced after implementing of TMDL, it was found that the effect of land-use regulations on industrial and livestock facilities in SWPA were mitigated by the increase in the size of large facilities. Since 1999 when the emission standard of public sewage treatment plants (STP) was changed, the water quality of Lake Paldang has increased despite the increase of pollutant source. Since emission standard of STP changed in 2012 (BOD 5 mg/L, TP 0.2 mg/L), BOD concentration in Lake Paldang has also improved to the level of water quality in the early 1990s where as TP concentration has remained at its lowest since 1990. BOD and TP average discharge concentration of 43 STP (${\geq}500m^3/day$) in 2016 have been maintained $1.7{\pm}0.7mg/L$ and $0.06{\pm}0.02mg/L$ respectively. While the discharged load of STP in SWPA was decreased by the concentration management, the contribution rate to the total discharged load of non-point pollutants increased to 70 % in 2015, and the contribution rate to the point discharged load of individual treatment facilities increased to 80 %.

• Journal of Korean Society on Water Environment
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• v.39 no.4
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• pp.316-328
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• 2023

In this study, the characteristics of nonpoint pollutant outflow and contribution rate of pollution in Songya-stream mainstream and tributaries were analyzed. Further, water pollution management and improvement measures for pollution-oriented rivers were proposed. An on-site investigation was conducted to determine the inflow of major pollutants into the basin, and it was found that pollutants generated from agricultural land and livestock facilities flowed into the river, resulting in a high concentration of turbid water. Based on the analysis results of the pollution load data calculated through actual measurement monitoring (flow and water quality) and the occurrence and emission load data calculated using the national pollution source survey data, the S3 and S6 were selected as the concerned pollution tributaries in the Songya-stream basin. Results of cluster analysis using Pearson correlation coefficient evaluation and Density based spatial clustering of applications with noise (DBSCAN) technique showed that the S3 and S6 were most consistent with the C2 cluster (a cluster of Songya-stream mainstream owned area) corresponding to the mainstream of Songya-stream. The analysis results of the major pollutants in the concerned pollution tributaries showed that livestock and land pollutants were the major pollutants. Consequently, optimal management techniques such as fertilizer management, water gate management in paddy, vegetated filter strip and livestock manure public treatment were proposed to reduce livestock and land pollutants.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.5
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• pp.930-934
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• 2006

In this study, we conducted water-quality analysis of wastewater and in-situ flow measurement using automatic flow rate measuring instrument to identify characteristics of wastewater in urban areas, and collected samples in gutter fur storm water drain, rainfall bucket, and aqueduct of pipe from roof, and outfalls of basins to examine the contribution by pollution origins such as base wastewater, atmospheric washing, runoff by roof surface, runoff by road surface, erosion of sewer sediment. In the result, the concentration of pollutants reached peak in the beginning of rainfall due to first flush, was 3 to 10 times higher than average concentration of dry period, and was lower than that of dry period due to dilution of storm water. In the analysis of the contribution by pollution origins, the ratio of load by sewer sediment resuspension to the total pollution load was 54.6% fer COD, and 73.3% fur SS. Accordingly, we can reduce the total pollutant load by periodical dredging and washing of sewer sediment, and control the loadings by overflow of combined sewer overflows.

• Journal of Wetlands Research
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• v.11 no.2
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• pp.67-76
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• 2009

The contribution of pollutant loadings from non-point source (NPS) to the four major rivers in Korea exceeded 22~37 % of the total loadings in 2004 and is expected to reach 60 % in 2020. Most of NPS loadings are coming from urban areas, especially from paved areas. Because of high imperviousness rate, many types of NPS pollutant are accumulating on the surface during dry periods. The accumulated pollutants are wash-off during a storm and highly degrading the water quality of receiving water bodies. For this reason, the Korean Ministry of Environment (MOE) developed the Total Maximum Daily Load (TMDL) program to protect the water quality by managing the point source and NPS loadings. NPS has high uncertainties during a storm because of the characteristics of rainfall and watershed areas. The rainfall characteristics can affect on event mean concentrations (EMCs), mass loadings, flow rate, etc. Therefore, this research was performed to determine EMCs for rainfall ranges from transportation landuses such as road and parking lot. Two sites were monitored over 45 storm events during the 2006/06 through 2008/10 storm seasons. Mean TSS EMCs decrease as rainfall ranges increase and highest at less than 10mm rainfall. The results of this study can be used to determine the efficient scale of BMP facility considering specific rainfall range.

• Journal of Korean Society on Water Environment
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• v.22 no.2
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• pp.277-287
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• 2006

Production loads of the contaminants near the Nakdong-river are, BOD : $1,006ton{\cdot}day^{-1}$, TN : $117ton{\cdot}day^{-1}$, and TP : $21ton{\cdot}day^{-1}$. Among the sources of contamination, the biggest contribution to the production load was shared by the human population, which maintains 40.7% of BOD, 44.2% of TN, and 52.5% of TP production. Similarly, among the sources of discharge load, the human population contributed 45.0% of BOD, 34.5% of TN, and 45.8% of TP. Results of flow investigation in 2001 and 2002 indicate that among the side streams, Nam-river showed the greatest average flow. In case of main stream flow, it was increased in the downstream due to the increase of the influents from the side streams. In case of BOD, COD, TOC and SS, high values were detected at Keumho-river where industrial wastewater was discharged as high level concentration. In case of the main stream, Koryoung point where direct influence of Keumho-river and Seongseo industrial complex is evident showed high BOD, COD and TOC. Oxidized nitrogen compounds and total nitrogen showed similar patterns of BOD, COD, and TOC. Especially, nitrate nitrogen was relatively high at all points. However, in case of Chlorophyll-a, relatively high values were observed at mid- and downstream areas such as Koryoung, Namjee, Soosan, Moolkeum and Hakooeun. This could be caused by the slow flow rate and the abundant nutrient salts attributed by the side streams. Relatively better water quality was observed in 2002 when the flow was relatively abundant than that in 2001. Results of investigation during 2001-2002 showed that delivery load increased as the flow reaches downstream. In 2001, delivery loads at the downstream Soosan-bridge were BOD $22,152ton{\cdot}day^{-1}$, COD $45,467ton{\cdot}day^{-1}$, TN $22,062ton{\cdot}day^{-1}$, TP $926ton{\cdot}day^{-1}$. Delivery loads in 2002 were increased due to the increase of the rainfall. They are BOD $25,876ton{\cdot}day^{-1}$, COD $64,200ton{\cdot}day^{-1}$, TN $41,101ton{\cdot}day^{-1}$, and TP $1,362ton{\cdot}day^{-1}$.

• Korean Journal of Ecology and Environment
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• v.39 no.2 s.116
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• pp.187-197
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• 2006

A mathematical modeling program called Hydrological Simulation Program-FORTRAN (HSPF) developed by the United States Environmental Protection Agency(EPA) was applied to the Yongdam Watershed to examine its applicability for loading estimates in watershed scale. It was run under BASINS (Better Assessment Science for Integrating point and Nonpoint Sources) program, and the model was validated using monitoring data of 2002 ${\sim}$ 2003. The model efficiency of runoff was high in comparison between simulated and observed data, while it was relatively low in the water quality parameters. But its reliability and performance were within the expectation considering complexity of the watershed and pollutant sources and land uses intermixed in the watershed. The estimated pollutant load from Yongdam watershed for BOD, T-N and T-P was 1,290,804 kg $yr{-1}$, 3,753,750 kg $yr{-1}$ and 77,404 kg $yr{-1}$,respectively. Non-point source (NPS) contribution was high showing BOD 57.2%, T-N 92.0% and T-P 60.2% of the total annual loading in the study area. The NPS loading during the monsoon rainy season (June to September) was about 55 ${\sim}$ 72% of total NPS loading, and runoff volume was also in a similar rate (69%). However, water quality was not necessarily high during the rainy season, and showed a decreasing trend with increasing water flow. Overall, the BASINS/HSPF was applied to the Yongdam watershed successfully without difficulty, and it was found that the model could be used conveniently to assess watershed characteristics and to estimate pollutant loading in watershed scale.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.966-970
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• 2009

경기도 용인시, 오산시와 화성시 지역의 농업용수와 공업용수의 공급원으로 이용되고 있는 신갈호는 현재 유입하천으로부터 미처리된 도시하수, 공장 폐수, 축산 폐수 등의 점오염원 및 도시 지역 불투수층에 쌓여있는 오염물질인 비점오염원이 무분별하게 유입되어 수질이 매우 악화되어 용수로의 사용이 어려운 지경에 달하였으며, 자연정화능력도 감소하는 등 심각하게 오염되었다. 또한 최근에는 신갈호 유역의 개발에 따른 토지이용 변화로 신갈호 유역의 총오염부하량이 증가하고 있는 실정이다. 따라서 본 연구에서는 현재 날로 심각해지는 신갈호 유입하천의 비점오염원 조사를 통해 신갈호 및 유입하천의 기초데이터의 확충 및 현황 파악을 하고자 하였다. 본 연구에서는 강우 시 신갈호로 유입되는 3개의 유입지천인 신갈천(SG), 지곡천(JK), 공세천(KS)에서 비점오염부하량을 산정함으로써 강우 시 호소로 유입되는 총오염부하량 및 비점오부하량의 비율을 알아보고자 하였다. 강우사상에 따른 총 오염물질 부하량은 EMC 농도를 구한 후 총 유출유량을 곱하고 총 강우지속시간을 곱하여 산정하였다. 조사결과 강우기에 있어서 거의 모든 항목의 농도는 평수기보다 매우 높은 수치를 나타냈다. 특히 SS 농도는 토사의 하천유입으로 인해 다른인자에 비해 큰 변동폭을 나타내었으며, COD와 T-P는 토양입자에 흡착되어 함께 이동하기 때문에 SS와 밀접한 관계를 가졌다. 강우시의 각 유입하천별 오염부하 기여율은 SG의 경우 SS 74.1%, BOD 64.4%, COD 65.7%, T-N 63.8%, T-P 73.8%를 나타내었다. JK의 경우 SS 25.4%, BOD 31.5%, COD 30.5%, T-N 32.5%, T-P 24.2% 였고, KS의 경우 SS 0.5%, BOD 4.1%, COD 3.8%, T-N 3.7%, T-P 2.0%를 나타내었다. 강우시의 각 유입하천별 오염부하 기여율을 평수기때의 오염부하 기여율과 비교하였다. 비교결과 SS의 경우는 SG가 강우시에 74%, 평수기에 83%, BOD의 경우는 강우시 64%, 평수기 80%, T-N은 강우시 64%, 평수기에 84%, T-P의 경우는 강우시 74%, 평수기에 82%로 모든 항목에서 평수기에 신갈천이 신갈호의 오염부하에 미치는 영향이 큰 것으로 나타났는데, 이는 강우시 지곡천의 기여율이 평수기 보다 상대적으로 높아지기 때문인 것으로 판단된다.