• Journal of Wetlands Research
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• v.17 no.3
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• pp.303-310
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• 2015

Recently the water quality management policy gives priority to management the point source. Point pollution sources have definite emission points and are discharged to one point through a pipe. But Nonpoint pollution source (NPS) has uncertain pathway, pollutant load and runoff characteristics unlike point pollution sources, making them difficult to manage. Thus, the Korea government plans to develop and equip facilities that help reduce NPS so as to manage them more easily. But removal efficiency of Best Management Practice (BMPs) is in influenced by rainfall, hydrologic condition like natural phenomenon, so factors of removal efficiency are difficult. Thus there is a need for multilateral research about many factors that affect removal efficiency for removal facility design of proper non-point pollution. In this research, mapping, vegetation coverage and retention time were investigated in the case of factors that affect removal efficiency in grassed swale, a nature-type non-point removal facility. Grassed swale obtained changed of coverage using Braun-Blanquet within swale and retention time was obtained from point that rainfall effluent enters into swale to the time that first outflow starts. Besides, correlation analysis was obtained using pearson correlation analysis method. As a result, it was shown that removal efficiency increases as retention time is longer in grassed swale and that retention time increases as vegetation coverage is higher.

• KCID journal
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• v.19 no.1
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• pp.40-49
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• 2012

This study was performed to monitor the runoff of sandy soils on alpine uplands between March 2008 and December 2009, and assess non-point source pollution load. The fields were used to cultivete poteto in 2008 and radish in 2009. The fertilizers used in 200S, compared to those used in 2009, contained 2.1 times of nitrogen, 1.9 times of phosphorous, and 2.3 times of potassium. In 2008, the annual pollution load indiceted SS 2,908.47kg/ha/yr, COD 67.95kg/ha/yr, BOD 50.72kg/ha/yr, TN l3.29kg/ha/yr, and TP 9.97kg/ha/yr. In 2009, the annual pollution load indiceted SS 3,908.34kg/ha/yr, COD 225.04kg/ha/yr, BOD 156.96kg/ha/yr, TN 18.88kg/ha/yr, and TP 36.41kg/ha/yr. The amount of fertilizers used was about twice greeter in 2008, but the amounts of TN in pollution load per unit of rainfall were similar by 0.031kg/ha/mm to 0.029kg/ha/mm, whereas the amounts of COD (0.16kg/ha/mm to 0.35kg/ha/mm), BOD (0.12kg/ha/mm to 0.24kg/ha/mm), and TP (0.023kg/ha/mm to 0.057kg/ha/mm) doubled in 2009. We can infer thet the surface covering by the growth of crop mainly affected the transport of T-N through the subsurface flow to reduce non-point source pollution.

• Journal of Korean Society on Water Environment
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• v.28 no.3
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• pp.453-459
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• 2012

In this study, Song-Cheon river Basin located at Dae-kwan-lyong Meyn in Kang-Won Province was monitored to analyze characteristics of non-point source pollution during the snowmelt period. The characteristics of NPS pollution such as runoff, change in water quality and pollutant loads by snowmelt were investigated from 23th February 2010 to 27th April 2010. The results showed that The climate change effects flow, turbidity and concentration of SS and COD with showing similar trend of fluctuation. Daily pollutant loads per unit area were SS 74.43 kg/ha/day, COD 1.25 kg/ha/day, BOD 0.21 kg/ha/day, TN 0.717 kg/ha/day, TP 0.141 kg/ha/day and the flow weight mean concentration has been SS 985.97 mg/L, COD 16.28 mg/L, BOD 2.67 mg/L, TN 9.302 mg/L, TP 1.834 mg/L, respectively. The flow and pollutant loads both of SS and of COD significantly increased during the snowmelt period. Because structurally loosen soil by freezing and thawing deteriorates water quality, research and management measures will be needed.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.4
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• pp.123-132
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• 2018

The purpose of this study was to evaluate the reduction effect of non point source (NPS) pollution in Haean highland agricultural catchment ($62.8km^2$) for 13 BMP scenarios under RCP (Representative Concentration Pathway) 4.5 and 8.5 scenarios. Under the present climate condition, the BMP (best management practices) reduction efficiency of SS (suspended solid), T-N (total nitrogen), and T-P (total phosphorus) showed +25.7%, +4.2%, and +16.1% for VFS (vegetative filter strip), +0.1%, +15.6%, and +5.7% for FC (fertilizer control), and +6.3%, -2.9%, and +3.9% for RSM (rice straw mulching) respectively. In general, effective was the best for SS and T-P reductions, and the FC was the best for T-N reduction. The negative effect of T-N on RSM was induced by increase in infiltration and solute transport to baseflow. Under the future climate change scenarios, the SS, T-N, and T-P reduction efficiency showed the range of +1.9~+11.6%, -1.9~+0.2%, and +5.3~+11.9% respectively. The 3 BMPs (VFS, FC, and RSM) application in the future showed negative and little differences (-0.5~+1.6%) for SS and T-N reduction efficiencies while T-P reduction efficiency showed +0.3~+7.6% comparing with the baseline period. To achieve an increase in the reduction efficiency of future SS and T-N by +2~+10%, the combined application of more than two BMPs is necessary.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.3
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• pp.91-101
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• 2012

This study is to assess the runoff characteristics of nonpoint source pollution loads for Jecheon and Jangpyeong stream watersheds located in the upstream of Chungju lake. The SWAT (Soil and Water Assessment Tool), a physically based distributed hydrological model was calibrated and verified using 5 years (2006 to 2010) streamflow and water quality data. The Nash-Sutcliffe model efficiency for streamflow was 0.60~0.92 and the determination coefficients for sediment, Total Nitrogen (T-N), and Total Phosphorous (T-P) were 0.53~0.71, 0.51~0.91 and 0.38~0.85 respectively. The results showed that the Sediment, T-N, and T-P of Jangpyeong stream were 40.0~60.9 %, 34.8~64.1 % and 76.5~83.9 % higher than Jecheon stream watershed during wet days. The results evaluated high NPS loads at Jangpyeong stream because the percentage of urban and upland crop cultivation area Jangpyeong stream watershed was higher than Jecheon stream watershed.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.425-428
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• 2002

This study has been carried out to analized of long term changes of water quality with regard to main pollutant sources in agricultural reservoirs on the basis of data during 1996-2001. The major source was domestic wastewater(DWW) and water pollution by non-point sources(NPS) is increasing as time goes. It was determined that Seasonly average values of DWW were pH $7.6{\sim}8.7$, COD $7.0{\sim}9.4$, T-N $0.74{\sim}2.07$, T-P $0.05{\sim}0.62$, Live-stock wastewater(LWW) were pH $7.5{\sim}8.9$, COD $5.5{\sim}9.8$, T-N $0.57{\sim}1.91$, T-P $0.04{\sim}0.13$, NPS were pH $7.1{\sim}8.3$, COD $3.1{\sim}5.2$, T-N $0.29{\sim}1.44$, T-P $0.02{\sim}0.07$. Fluctuation of DWW and LWW were very wide and variable long term patterns of them were similar. Trophic states by Carlson Index of DWW and LWW was classified as eutrophic to hypretrophic from chl-a, T-P concentration.

• Journal of Wetlands Research
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• v.12 no.3
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• pp.165-175
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• 2010

Recently, various development projects have occurred due to rapid industrialization and urbanization. Both industry and population grew rapidly which causes a corresponding rise in pollution. The accumulated pollutants are washed-off during rainy days, highly degrading the water quality of the receiving water body. This is because a lot of non point source (NPS) pollutants were accumulated on the surface during dry periods. This research focuses on the development of Eco-Bio Filter (EBF) system that treats NPS pollutants. It is constructed at Kongju National University campus. The EBF is a type of a structured infiltration system that falls under the category of Low Impact Development (LID) hydrologic design practices. The monitoring of rain events was performed. It includes the development of design, the lessons learned from the post-construction testing and the improvements in the renovation made. After a series of monitoring, the MOE will use the results to apply the design to other areas in the country.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.2
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• pp.51-60
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• 2021

Effective nonpoint source (NPS) pollution management requires frequent water quality monitoring, which is, however, often costly to be implemented in practice. Statistical techniques and machine learning methods allow us to identify and focus on fundamental environmental variables that have close relationships with NPS pollutants of interest. This study developed surrogate models to predict the concentrations of suspended sediment (SS) and total phosphorus (T-P) from turbidity and runoff discharge rates using multiple linear regression (MLR) and random forest (RF) methods. The RF models provided acceptable performance in predicting SS and T-P, especially when runoff discharge rates were high. The RF models outperformed the MLR models in all the cases. Such finding highlights the potential of RF techniques and models as a tool to identify fundamental environmental variables that are measured in relatively inexpensive ways or freely available but still able to provide information required to quantify the concentrations of NP S pollutants. The analysis of relative importance rates showed that the temporal variations of SS and T-P concentrations could be more effectively explained by that of turbidity than runoff discharge rate. This study demonstrated that the advanced statistical techniques such as machine learning could help to improve the efficiency of NPS pollutants monitoring.

• Korean Journal of Environmental Agriculture
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• v.32 no.4
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• pp.355-358
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• 2013

BACKGROUND: Water-born pollution loads by agricultural non-point source (NPS) pollution are expected to become intensified due to ongoing precipitation change. Therefore, it is essential to develop a best management practice (BMP) that is suitable to agricultural environments in Korea. This study aimed to develop an environmental-friendly BMP to reduce NPS pollution load by agricultural activities. An eco-friendly way, small drainage pond, was suggested in this study to avoid direct drainage of agricultural runoffs and eventually reduce the amount of pollutants discharged into the surrounding aqua-environment. METHODS AND RESULTS: A small pond ($12m^2$) was constructed at the corner of a rice paddy field ($1,715m^2$) located in Suwon, Korea. Water was allowed to drain only via a small drainage pond. Sampling was repeatedly made at two locations, one from an entrance and the other from an exit of a pond, during the rice cultivation period (May to October, 2012). Generally, sampling was made only when runoff water drained through a pond, such as during and/or after rain (irrigation). The water quality analysis showed that all quality parameters (SS, $COD_{Mn}$, T-N, and T-P) were improved as water passed through the pond. The amount of runoff water was reduced by 96~100%. Suspended solids and COD concentrations was reduced by 79.3% and 45.6%, respectively. In case of T-N and T-P concentrations, the reduction rates were 52.2% and 60.5%, respectively and the amount of T-N and T-P were reduced by 16.3~73.0% and 15.4~70.1%, respectively. CONCLUSION(S): Our data implies that agricultural NPS pollution from rice paddy fields can be effectively managed when an appropriate drainage water management practice is imposed. In this paper, it was suggested that an installation of a small drainage pond can be effective to prevent not only the nutrient loss from rice fields but also pollutant discharge to surrounding water environments.

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.4
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• pp.21-27
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• 2014

Pig slurry has been considered as environmental waste to be treated in an appropriate manner. Moreover, water-born pollution loads by agricultural non-point source(NPS) pollution are expected to become intensified due to ongoing precipitation change. This study was conducted to develop a best management practice to reduce NPS pollution load by agricultural activity with pig manure compost. An eco-friendly way, small drainage pond, was suggested in this study to avoid direct drainage of agricultural runoffs and eventually reduce the amount of pollutants discharged into the surrounding aqua-environment. A small pond($12m^2$) was constructed at the corner of a rice paddy field($17,15m^2$) located in Suwon, Korea. Water was allowed to drain only via a small drainage pond. Sampling was repeatedly made at two locations, one from an entrance and the other from an exit of a pond, during the rice cultivation period(May to October, 2013). Generally, sampling was made only when runoff water drained through a pond, such as during and/or after rain(irrigation). The water quality analysis showed that all quality parameters(SS, $COD_{Mn}$, T-N, and T-P) were improved as water passed through the pond. The amount of runoff water was reduced by 67.8%. Suspended solids and $COD_{Mn}$ concentrations were reduced by 79.8% and 71.9%, respectively. In case of T-N and T-P amounts, the reduction rates were 73.6% and 74.9%, respectively. Our data implies that agricultural NPS pollution from rice paddy fields with pig manure-based fertilizer can be effectively managed when an appropriate drainage water management practice is imposed.