• Journal of Korean Society on Water Environment
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• v.22 no.1
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• pp.104-109
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• 2006

TPLMS programs in four large rivers have been developed to improve the water quality from possible pollutants originated from watershed areas. The success of TPLMS program is depended on nonpoint source control. Currently, the pollutant loading from nonpoint pollution sources is gradually increasing as developing the nearby watershed. However, there are not enough data concerning on nonpoint pollution in Korea because of lacking of monitoring activities. It is the main reason of uncertainty. Therefore, this manuscript will summarize the EMCs in various landuses based on monitoring program. Also the EMC in each paved area will be compared and discussed to find the differences. When the EMC is compared by average monitored sample concentrations, the EMC values are 2-4 times higher than sample concentrations. It means the monitoring program is very important in the field of nonpoint pollution. The pollutant loadings from bridge landuse is higher than loadings from parking lot and highway because of more traffic activities.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.521-526
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• 1998

This study was initiated to build runoff plots, install soil and water quality monitoring systems and collect background data from the plots and soils to assess runoff the nonpoint source pollution and soil physical change in mountainous soils. Eleven 3 $\times$ 15 m runoff plots and monitoring systems were installed at a field of National Alpine Agricultural Experiment Station to monitor soil physical change, and discharge of nonpoint source pollutant. Corn and potato were cultivated under different fertilizer, tillage and residue cover treatments. The soil has a single-layered cluster structure that has a relatively good hydrologic properties and can adsorb a large amount of nutrient. 11 runoff plots were treated and monitored with respect to physical property of the soil, runoff and sediment discharge.

• Journal of Korean Society on Water Environment
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• v.25 no.2
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• pp.311-321
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• 2009

Long-Term Hydrologic Impact Assessment (L-THIA) was modified to improve runoff and pollutant load prediction for Korean watersheds with changes in land use classification and event mean concentration produced from observed data in Korea. The L-THIA model was linked with SCE-UA, which is one of the global optimization techniques, to automatically calibrate direct runoff. Modified L-THIA model was applied to Gumho River Basins to analyze spatial distribution of nonpoint source pollution. The results of model calibration during 1991~2000 and validation during 1981~1990 for direct runoff represented high model efficiency of 0.76 for calibration and 0.86 for validation. As a results of spatial analysis of nonpoint source pollution, the BOD was mainly loaded from urban area but SS, TN, and TP from agricultural area which is mainly located along the stream. Modified L-THIA model improve its accuracy with minimum imput data and application efforts. From this study, we can find out the L-THIA model is very useful tool to predict direct runoff and pollutant loads from the watershed and spatial analysis of nonpoint source pollution.

• Journal of the Korean GEO-environmental Society
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• v.13 no.4
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• pp.37-44
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• 2012

This study investigated on the adsorption of nonpoint pollution source using the Sand, hydroxyapatite(HAP), Zeolite and mixed culture. The adsorption of nonpoint pollution source on Sand, hydroxyapatite(HAP), Zeolite and mixed culture was investigated during a series of batch adsorption experiments. After the batch absorption experiments analysed COD, T-N, T-P on adsorption water. The experimental data was analysed using the pseudo-first-order adsorption kinetic models. Langmuir and Freundlich isotherm models were tested for their applicability. The maximum adsorbed amount $(Q_{max})$ of COD were found to be sand 0.0511mg/g, HAP 0.1905mg/g, Zeolite 1.0366mg/g and Mixed media 0.7444mg/g. The maximum adsorbed amount $(Q_{max})$ of T-N were found to be sand 0.0159mg/g, HAP 0.0537mg/g, Zeolite 0.5496mg/g and Mixed media 0.1374mg/g. The maximum adsorbed amount $(Q_{max})$ of T-P were found to be sand 0.0202mg/g, HAP 0.1342mg/g, Zeolite 0.0462mg/g and Mixed media 0.1180mg/g. As a result, the mixed media was effective to remove nonpoint pollution source.

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.2
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• pp.61-74
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• 2007

A mathematical modeling program called Hydrological Simulation Program-FORTRAN (HSPF) developed by the United States Environmental Protection Agency (EPA) was applied to Hwaseong watershed. It was run under BASINS (Better Assessment Science for Integrating Point and Nonpoint Sources) program, and the model was validated using monitoring data of $2002{\sim}2005$. The model efficiency of runoff ranged from good to fair in comparison between simulated and observed data, while it was from very good to poor in the water quality parameters. But its reliability and performance were within the expectation considering complexity of the watershed and pollutant sources. The nonpoint source (NPS) loading for T-N and T-P during the monsoon rainy season (June to September) was about 80% of total NPS loading, and runoff volume was also in a similar range. However, NPS loading for BOD ($55{\sim}60%$) didn't depend on rainfall because BOD was mostly discharged from point source (more than 70%). And water quality was not necessarily high during the rainy season, and showed a decreasing trend with increasing water flow. BASINS/HSPF was applied to the Hwaseong watershed successfully without difficulty, and it was found that the model could be used conveniently to assess watershed characteristics and to estimate pollutant loading including point and nonpoint sources in watershed scale.

• Journal of Environmental Impact Assessment
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• v.12 no.5
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• pp.349-358
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• 2003

Water pollution of Hwanggujicheon stream is severe because urban area of Suwon City is included in the basin. A countermeasure for water quality prevention of the stream is necessary. In this study, nonpoint pollutant load of BOD, SS, TN and TP are estimated using SWMM. The result indicates that BOD, SS, TN and TP loads during 3 months from July to September are 67.0%, 60.8%, 54.7% and 74.5% of the annual total load, respectively. We can see that most of nonpoint pollutant loads are generated in the rainy season. Annual nonpoint pollutant loads of BOD, SS, TN and TP in the Hwanggujicheon stream are 342 ton, 1,500 ton, 480 ton and 12.6 ton, respectively.

• Journal of Environmental Impact Assessment
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• v.18 no.6
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• pp.393-399
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• 2009

The water of rivers and lakes are affecting by point and nonpoint source pollutions. The point source pollution can be controlled by establishing the treatment plants. However, nonpoint source pollution by various human activities is not easy to be controlled because it is difficult to determine the exits of the water flow and have many exit points. Due to contribution of nonpoint source pollution, the achievement ratio of water quality in rivers and lakes is not high. TMDL is the outstanding water quality control policy because all of the pollutant loadings from the watershed area are counting on the input loads. Our aqua-ecosystem has self-purification process by biological, physical and ecological processes. The self-purification process can remove the pollutant load from background concentrations. Usually forest area is main source of background concentrations. In Korea, about 70% of the national boundary area consists of mountains. This study is conducting as part of long-term monitoring to determine the Event Mean Concentration during a storm. The monitoring was performed on a broad-leaved tree area.

• Journal of Korean Society on Water Environment
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• v.33 no.1
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• pp.97-106
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• 2017

In this study, the characteristics of nonpoint source pollutant loads from separate sewer overflow (SSO) and combined sewer overflow (CSO) were evaluated during 2016 in Namyangju city, Korea. Five rainfall events were monitored during 2016 with ranging from 14.5 mm to 121.5 mm. The runoff ratio of CSO was higher than that of SSO because only design volume of maximum sanitary sewer ($1Q_h$) was transported and treated and $2Q_h$ was overflowed to waterbody during rainy day although combined sewer system was designed to transport $3Q_h$ to treatment system. The event mean concentrations (EMCs) and pollutant loads from CSO were higher than those from SSO. BOD and COD of CSO, and TOC and TN of SSO represented distinct first flush phenomena. The inadequate management in combined sewer system from which the untreated $2Q_h$ from CSO was overflowed to waterbody during rainy day could influence on high pollutant loads and first flushing. Treating $2Q_h$ from CSO, source control such as low impact development, and treating outflow from SSO were strongly recommended to control non-point source pollution in urban area.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.454-458
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• 2007

Nonpoint source (NPS) pollution is a serious problem causing the degradation of soil and water quality. Concentrated overland flow is the primary transport mechanism for a large amount of NPS pollutants from hillslope areas to downslope areas in a watershed. In this study, a soil erosion model, nLS model, to identify transitional overland flow regions (i.e., ephemeral gully head areas) was developed using the kinematic wave overland flow theory. Spatial data, including digital elevation models (DEMs), soil, and landcover, were used in the GIS-based model algorithm. The model was calibrated and validated using gully head locations in a large agricultural watershed, which were identified using 1-m aerial photography. The model performance was better than two previous approaches; the overall accuracy of the nLS model was 72 % to 87 % in one calibration subwatershed and the mean overall accuracy was 75 to 89 % in four validation subwatersheds, showing that the model well predicted potential transitional erosion areas at different watersheds. However, the user accuracy in calibration and validation was still low. To improve the user accuracy and study the effects of DEM resolution, finer resolution DEMs may be preferred because DEM grid is strongly sensitive to estimating model parameters. Information gained from this study can improve assessing soil erosion process due to concentrated overland flow as well as analyze the effect of microtopographic landscapes, such as riparian buffer areas, in NPS control.

• Journal of Environmental Health Sciences
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• v.35 no.3
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• pp.220-225
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• 2009

This study evaluates the water quality of the river near the alpine farmland in the upper Naerin stream, which is a typical stream of the upper Bukhan River with muddy water generation, by the flow examination, it aims to estimate the characteristics of nonpoint sources flowing out from the investigated area and figure out effective methods to reduce them. According to the result of water quality examination, the average BOD of the area not affected by the cultivated land among the areas of the upper Naerin River was 0.47mg/l, and total phosphorous was 0.007mg/l; thus, it maintained the cleanliness level of Ia. The average BOD of the area with the alpine farmland was 0.52mg/l, which was similar to the one of the non-cultivated land. But total phosphorous concentration was 0.023mg/l, which was more than three times higher than the area belonging to level II due to the effect of fertilizer ingredients discharged from the cultivated land. About the loadings of the investigated area generated from each of the pollution sources, BOD was 878.5kg/day and total phosphorous was 79.7kg/day. Moreover, for the load density, BOD was $2.22kg/day.km^2$ and total phosphorous was shown as $0.20kg/day.km^2$. Regarding the rates generated from nonpoint sources like land among the loadings per pollution sources, BOD was 54%, total nitrogen was 91%, and total phosphorous was 73.4%. Therefore, it was shown that most of the nutrients were produced from the nonpoint sources. The level of BOD runoff loading in the Jaun River area, where nonpoint sources were mainly generated, was 37.1kg/day and total phosphorous was 1.33kg/day. The flow rates to the generated amount were estimated as 10.5% and 4.7% each.