• 한국농공학회지
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• 제45권7호
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• pp.38-48
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• 2003

Lake water quality assessment information is useful to anyone involved in lake management, from lake owners to lake associations. It provides lake water quality criteria, which can improve the ways how to manage out lake resources and how to measure current conditions. It also provides a knowledge base so that the lakes can be protected and restored. Here, the Freshwater Lake Water Quality Management System(FLAQUM) was developed. The results of FLAQUM application by scenario proved that pollutant load at rainfall by the nonpoint sources was much more than normal times at rainfall. From the result of Scenario I (pollutant source increase case), the concentrations of Boryeong freshwater lake were BOD 9.43mg/L, T-N 4.53 mg/L and T-P 0.21 mg/L, respectively, and those values exceed the standard of agricultural water. And in case of Scenario I and II(the present case) excluding Scenario III (pollutant source decrease case), all of T-N and T-P are either mesotrophication or eutrophication, on the other hand when 60% of pollution source is removed, the concentrations of Scenario III were BOD 3.21 mg/L, T-N 0.95 mg/L, T-P 0.11 mg/L, respectively, and which satisfies the standard of agricultural water quality.

• 한국물환경학회지
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• 제26권5호
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• pp.761-767
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• 2010

This study introduces a model of territorial analysis on Chungcheongnam-do Nonsan-chun valley area, which gives an example of a method of selecting the management area for non-point pollution source from land use to help eliminate its source. High discharge load per unit area signify high level of land ratio with high level of basic unit of development load (including factory sites, school sites, roadways), which mean that there are a significant level of urbanization. It is these areas with the examination of the water quality of the nearby river that should be considered as the management area for non-point pollution source. Thus, the management area for non-point pollution source should be sought in areas with high discharge load per unit area and high density of water pollution area. When level of drainage is high the pollution density level is relatively lower, and when the level of drainage is low the density level is relatively higher. The level of pollution from non-point pollution source is much lower with more water flowing through. The possible non-point pollution source areas that were selected with these standards were then examined with the distance from the river, the slope angle, land usage, elevation, BOD discharge density load, T-N discharge density load, T-P discharge density load, and were given a level one through five. Out of the possible areas Nonsan-si Yeonmu-eup Anshim-li was the densest area, and it was given level one. The level one area should be examined further with the field analysis to be selected as the actual management area for non-point pollution source.

• Journal of Ecology and Environment
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• 제40권1호
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• pp.66-74
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• 2016

Background: When developing water quality improvement strategies for eutrophic lakes, questions may arise about the relative importance of point sources and nonpoint sources of phosphorus. For example, there is some skepticism regarding the effectiveness of partial reductions in phosphorus loading; because phosphorus concentrations are too high in hypertrophic lakes, in-lake phosphorus concentrations might still remain within typical range for eutrophic lakes even after the reduction of phosphorus loading. For this study, water quality and the phytoplankton and zooplankton communities were monitored in a hypertrophic reservoir (Lake Wangsong) before and after the reduction of phosphorus loading from a point source (a sewage treatment plant) by the installation of a chemical phosphorus-removal process. Results: Before phosphorus removal, Lake Wangsong was classified as hypertrophic with a median phosphorus concentration of $0.232mg\;L^{-1}$ and a median chlorophyll-a concentration of $112mg\;L^{-1}$. The dominant phytoplankton were filamentous cyanobacteria for the most of the ice-free season. Following the installation of the advanced treatment process, phosphorus concentrations were reduced to $81mg\;L^{-1}$, and the N/P atomic ratio increased from 42 to 102. Chlorophyll-a concentrations decreased to $42{\mu}g\;L^{-1}$, and the duration of cyanobacterial dominance was confined to the summer season. Cyanobacteria in spring and autumn were replaced by diatoms and cryptomonads. Filamentous cyanobacteria in summer were replaced by colony-forming unicellular Microcystis spp. It was remarkable that zooplankton biomass increased despite the decrease in phytoplankton biomass, and especially cladoceran zooplankton which increased drastically. These responses to the reduction of point source P loading to Lake Wangsong imply that reducing the point source P loading can have a big impact even when nonpoint sources account for a large fraction of the total annual phosphorus loading. Conclusions: Our results also show that the phytoplankton community can shift to decreased cyanobacterial dominance and the zooplankton community can shift to higher cladoceran dominance, even when phosphorus concentrations remain within the typical range for eutrophic lakes following the reduction of phosphorus loading.

• 한국농공학회논문집
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• 제54권4호
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• pp.1-8
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• 2012

This study is to assess the reduction of non-point source pollution loads for rice straw surface covering of upland crop cultivation at a watershed scale. For Byulmi-cheon watershed ($1.21km^2$) located in the upstream of Gyeongancheon, the HSPF (Hydrological Simulation Program-Fortran), a physically based distributed hydrological model was applied. Before evaluation, the model was calibrated and validated using 9 rainfall events. The Nash-Sutcliffe model efficiency (NSE) for streamflow was 0.62~0.78 and the NSE for water quality (Sediment, T-N, and T-P) were 0.68, 0.60, and 0.58 respectively. From the field experiment of 16 rainfall events, the rice straw covering reduced surface runoff average 10 % compared to normal surface condition. By handling infiltration parameter (INFILT) in the model, the value of 16.0 mm/hr was found to reduce about 10 % reduction of surface runoff. For this condition, the reduction effect of Sediment, T-N, and T-P loads were 87.2, 28.5, and 85.1 % respectively. The rice straw surface covering was effective for removing surface runoff dependent loads such as Sediment and T-P.

• The Korean Journal of Ecology
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• 제18권3호
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• pp.341-351
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• 1995

The relationship between land uses and water quality was investigated at Kyong-an Stream. Some 70% of this watershed was forested area, half of which was comprised of Pinus densilflora community. Concentrations of $NH_4^{+},\;NO_3^{-},\;NO_2^{-}, total nitrogen, $Cl^{-},\;PO_4^{3-}$, DO, and BOD increased gradually from upstream to downstream, whereas heavy metals did not have such tendancy with the exception of a few sites. Urban area was significantly correlated with hardness and chloride concentration. Relationship among phosphate concentration(P), cultivated field area(F), and stream length(S) in each basin was P = 1.7912 F/S＋0.0103. the concentration of $NH_4^{＋}$ was positively correlated with the population size and cow density within the catchment. The effect of urban area(U) and stream length of the pH(pH) was represented by pH = -4.7344 U/S＋6.52. It can be concluded that the control of nonpoint source pollution as well as point source pollution is one of the important problems of water quality management, especially geological properties must be considered for sustainable development.

• 환경영향평가
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• 제23권1호
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• pp.19-27
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• 2014

The purpose of this study is to provide a base line data to improve the water quality in the Yeongsan River basin. As the major factor that affects the water quality of Yeongsan River is nonpoint pollution source, in order to find a resolve to improve the quality, a study was conducted to identify the correlation between the stream water quality and that of the land use. The study showed that the concentration of the contents in the water from the agricultural land environment was found to be higher as oppose to that found in the content of the water from the forest land. As a result, it can be deducted that agricultural land deteriorates water quality whereas that of the forest land is of much better quality. Therefore, it is highly recommended to take advanced improved care of agricultural land close to a water source to improve the quality of Yeongsan River basin.

• 생태와환경
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• 제40권2호
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• pp.201-213
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• 2007

본 연구에서는 북한강 상류 지역인 소양강댐 유역에 BASINS/WinHSPF모델을 적용하였다. WinHSPF는 도시와 농촌지역 등이 혼재된 토지이용형태를 보이는 유역에 적용하기 적합한 모델로서, 산림이 대부분인 소양강댐 유역의 유출량 및 수질을 모의하고, 유역의 오염부하량을 분석하였다. 또한, 유역관리를 위해 인공습지와 저류지를 설치하였을 경우 WinHSPF의 Best Management Practice Evaluation(BMPRAC)을 통한 오염부하 삭감량을 산정하였다. WinHSPF 모델을 이용하여 유출량은 2000년부터 2004년까지, 수질 항목은 1990년부터 2004년가지 모의하였다. 모델 보정 결과 유량의 변화는 인북천, 북천, 내린천 세 곳 모두 강수량의 변화와 일치하여 변화하는 경향을 나타내고 있었고 모의치가 실측치를 대체적으로 잘 반영하였지만 유출량이 피크인 경우에 실측지에 비해 과소평가 되는 경향을 나타내었다. 이는 각 소유역에서 발생하는 강우량을 이용하여 모델을 구동한 것이 아니고, 일부 국한된 기상관측소의 자료만을 이용하였기 때문에 지역적인 차이가 나타났거나, 수위-유량 곡선을 통해 유출량을 산정하는 과정에서 수위가 높은 시기에 유량이 과도하게 계산된 경우가 있기 때문이라 판단된다. 수질항목은 온도, DO, BOD의 경우 예측값이 연중 수질변화패턴을 잘 반영하였다. TN과 TP는 모의치가 다소 과대, 과소평가되는 경향이 있었는데, 향후 보다 효율적인 유역관리를 위한 모델의 활용을 위해서는 정확하고 자세한 기상자료와 수문자료가 뒷받침되어야 하며, 실측지점의 특성을 대표할 수 있는 수질 및 유출량 측정이 이루어져야 할 것이다. 2000년부터 2004년가지 소양강댐 유역의 오염부하량은 강우량이 가장 논은 2003년에 BOD, TN, TP가 각각 4,109,674 kg $yr^{-1}$, 6,457,315 kg $yr^{-1}$, 104,186 kg $yr^{-1}$로 가장 높게 나타났다. 월별 부하량은 7월부터 9월에 배출되는 양이 BOD는 약 63.5%, TN 약 64.1%, TP는 약 64.4%를 차지하여, 강우 시 유출량이 증가하면 부하량도 비례하여 증가는 것으로, 강우 유출량에 많은 영향을 받고 있는 것으로 나타났다. 인북천, 북천, 내린천, 소양강 유역에서 BOD, TN, TP의 오염부하량은 약 98% 이상이 비점오염원으로부터 발생하는 것으로 분석되었는데, 이는 유역의 대부분이 산지와 농경지로서 산업시설과 같은 점오염원이 적고,강우 시 산림지역 및 농경지에서 많은 양의 비점오염원이 발생하기 때문으로 판단된다. WinHSPF모델의 BMPRAC를 이용하여 Scenario를 적용한 결과 부하량 삭감율은 저류지를 설치한 scenario 2가 가장 많이 감소하는 것으로 나타났다. 강우기(7${\sim}$9월)의 부하량 삭감율은 BOD의 경우 Scenario 1-1(처리용량 1,500 $m^3$ $day^{-1}$인 인공습지), scenario 1-2 (처리용량 1,000 $m^3$ $day^{-1}$인 인공습지), scenario 2(면적 4.2ha인 저류지)가 각각 연평균 6.9%, 4.8%, 7.1%의 감소를 보였다. TN은 4.7%, 3.4%, 13.4%의 삭감율을 나타내었으며, TP는 5.6%, 3.9%, 7.3%의 삭감율을 나타내었다. 본 연구에서는 적용하지 못하였으나, 인공습지와 저류지의 적절한 연계시스템을 적용한다면 저감시설 설치 부지면적과 비용의 감소뿐만 아니라 보다 효과적인 수질개선효과를 가져올 수 있으리라 판단된다.

• 한국습지학회지
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• 제18권1호
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• pp.94-99
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• 2016

최근 보다 높은 수준의 하천 수질 관리를 위해 비점오염물질 관리와 관련된 연구 및 사업이 지속적으로 수행되고 있다. 본 연구에서는 대규모 도시를 통과하는 도시하천의 수질관리방안 마련을 목적으로 본류와 연계된 5개 지천에 대한 강우시 비점오염물질 유출특성 분석을 수행하였다. 모니터링은 강우 전(Phase I), 강우 1시간 이후(Phase II), 강우 6시간 이후(Phase III)의 3단계로 수행되었으며, BOD, COD, TN, TP, SS 등의 수질항목과 유량이 측정되었다. 강우 시 5개 지천 모두에서 비점오염물질의 농도 및 유입부하량 증가가 확인되었으며, 상대적으로 우선 관리 대상 지천과 지천별 우선 관리 비점오염물질이 선정되었다. 해당 연구결과는 향후 도심지역 비점오염물질 모니터링 방안 및 점감시설 설치 등을 위한 기초 자료로 활용될 예정이다.

• 한국물환경학회지
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• 제23권6호
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• pp.951-960
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• 2007

Window interface to Hydrological Simulation Program-FORTRAN (WinHSPF) developed by the United States Environmental Protection Agency (EPA) was applied to the upstream of Nam-Han river watershed to examine its applicability for loading estimates in watershed scale and to evaluate non-point source control scenarios using BMPRAC in WinHSPF. The WinHSPF model was calibrated and verified for water flow using Ministry of Construction and Transportation (MOCT, 3 stations, 2003~2005) and water qualities using Ministry of Environment (MOE, 5 station, 2000~2006). Water flow and water quality simulation results were also satisfactory over the total simulation period. But outliers were occurred in the time series data of TN and TP at some regions and periods. Therefore, it required more profit calibration process for more various parameters. As a result, all the study was performed within the expectation considering the complexity of the watershed, pollutant sources and land uses intermixed in the watershed. The estimated pollutant load for annual average about $BOD_5$, T-N and T-P respectively. Nonpoint source loading had a great portion of total pollutant loading, about 86.5~95.2%. In WinHSPF, BMPRAC was applied to evaluate non-point source control scenarios (constructed wetland, wet detention ponds and infiltration basins). All the scenarios showed efficiency of non-point source removal. Overall, the HSPF model is adequate for simulating watersheds characteristics, and its application is recommended for watershed management and evaluation of best management practices.

• 한국물환경학회지
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• 제33권1호
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• pp.78-89
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• 2017

Water quality monitoring network data is being affected continuously due to non-point source pollution arising from agricultural land located on the Gwangsancheon outlet in the Nakdong River basin. In this study, we have performed analysis of water quality monitoring system, water quality pattern using SOM and water quality in the Gwangsancheon for sub-basin located at Gisan-myeon in the Nakdong River basin. We have developed and applied the model to estimate the runoff and non-point source loading. As a result of SOM pattern, the effect of non-point source pollution was the largest in the paddy fields and fields. As a result of the developed model, we found contribution rate and reduction rate for non-point source loading according to change of landuse because the reduction effect of nonpoint pollutants was 20.9% of SS, 9.9% of TN, 21.2% of TP and 8.9% of TOC depending on the landuse change.