• Journal of Korean Society of Environmental Engineers
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• v.38 no.4
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• pp.210-218
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• 2016

The pollutant removal efficiencies of stormwater runoff by settling were analyzed using field samples collected in 4 different raining events in a test bed installed in the Gwanpyung-Cheon stream in Daejeon. A 1.8 m high with 30 cm diameter cylindrical settling device was used for the settling test by measuring concentration of TSS, TP and TN for time and height. The pollutants removal rate was relatively high in the first 4 hours while 24 hours seem to be necessary to reach steady state in pollutant concentrations. However, there were no considerable differences in concentrations for height at a given time. This indicates most of particulate pollutant in the test seems to show independent settling with no interference to each other. Much part of particle sizes were distributed in the range of $10{\sim}100{\mu}m$. Average particulate fractions of TP and TN were estimated as 52.4% and 23.5%, respectively. This results explain why TN is difficult to remove by simple settling. This study indicates that a simple settling can provide effective method to remove significant amount of TSS and TP effectively and this can be used to protect urban river water quality.

• Ecology and Resilient Infrastructure
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• v.3 no.2
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• pp.100-109
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• 2016

Low impact development (LID) facilities are established for the purpose of restoring the natural hydrologic cycle as well as the removal of pollutants from stormwater runoff. Improved efficiency of LID facilities can be obtained through the optimized interaction of their major components (i.e., plant, soil, filter media, microorganisms, etc.). Therefore, this study was performed to evaluate the performances of LID facilities in terms of runoff and pollutant reduction and also to provide an optimal maintenance method. The monitoring was conducted on four LID technologies (e.g., bioretention, small wetlands, rain garden and tree box filter). The optimal SA/CA (facility surface area / catchment area) ratio for runoff reduction greater than 40% is determined to be 1 - 5%. Since runoff reduction affects the pollutant removal efficiency in LID facilities, SA/CA ratio is derived as an important factor in designing LID facilities. The LID facilities that are found to be effective in reducing stormwater runoff are in the following order: rain garden > tree box filter > bioretention> small wetland. Meanwhile, in terms of removal of particulate matter (TSS), the effectiveness of the facilities are in the following order: rain garden > tree box filter > small wetland > bioretention; rain gardens > tree box filter > bioretention > small wetland were determined for the removal of organic matter (COD, TOC), nutrients (TN, TP) and heavy metals (Cu, Pb, Cd, Zn). These results can be used as an important material for the design of LID facilities in runoff volume and pollutant reduction.

• KCID journal
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• v.14 no.2
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• pp.207-213
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• 2007

For sustainable development at a watershed, environment friendly site-specific management practices need to be developed and implemented. The soil and Water Assessment Tool(SWAT)model has been world-wide used to estimate stream flow, sediment, and nonpoint source pollutant loads, and effects on water quality of different management practices. In this study, the SWAT model was used to estimate the flow resources at Hwacheon areas using Digital Elevation Model(DEM),Land use, precipitation ,wind ,maximum and minimum temperature, solar radiation, humidity of watershed The R2 value and EI value for the comparison of SWAT estimated flow and measured flow were 0.87 and 0.67 respectively for calibration period, and the R2 value and E1 value for validation were 0.75 and 0.67 respectively. The comparison results show what the SWAT model is applicable to simulate hydrology behaviors at this study watershed.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.88-88
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• 2017

유역에서의 효율적인 수량 및 수질 관리를 위해서는 정확한 수문 구성요소에 대한 이해가 선행되어야 한다. 유출 수문곡선을 이용한 많은 연구가 수행되었음에도 불구하고 정확한 기저유출 산정에 관한 연구는 매우 제한적으로 수행되어 왔다. 수문학교과서에 수록된 다양한 기저유출 방법은 실제 장기 유출 수문곡선에 적용하는데 한계가 있으며, 유역의 다양한 유출특성을 반영할 수 없다. 따라서 본 연구에서는 USGS에서 개발한 기저유출 분리 모형와 SWAT BFlow, 그리고 WHAT 시스템에 특성에 대해서 분석하였으며, 이러한 모형을 이용한 기저유출 분석의 한계점을 제시하였다. 정확한 기저유출 분리를 위해서는 유역의 감수곡선 특성을 반영한 기저유출 분리가 이루어져야 하며, 주지하수 감수곡선처럼 유역 대표 감수 특성을 이용하기 보다는 유황이나 계절별 감수특성을 고려한 김수 특성 인자에 대한 연구가 필요하다. 이외에도 유역에서 기저유출로 인한 오염부하 특성을 NO3-N을 중심으로 분석하여 정확한 기저유출 산정의 중요성을 제시하였다. 이와 같이 기저유출과 같은 수문 구성 요소에 대한 정확한 이해 없이는 효율적인 수량 및 수질 관리가 어려울 것으로 판단된다.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.5
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• pp.59-64
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• 2008

The urban is possessing of various landuses such as commercial, industrial, residential and official areas. All of these landuses is including the paved areas that are roads and parking lots. The NPS (nonpoint sources) pollutants are generally originated from pavement areas in urban by human activities. Especially the roads are stormwater intensive landuses because of high vehicle activities and high imperviousness. The main NPS pollutants from roads are particulates and metals from vehicles and pavements. The Korea MOE (Ministry of Environment) is developing the NPS control program to reduce the NPS pollutants from the basins. However, it is not easy to control the NPS because it has high uncertainty by characteristics of rainfalls and watersheds. Therefore, this research was conducted on characterizing the runoff and providing mean EMC from roads. The monitoring were performed for total 16 rainfall events from a road in Youngin City since 2006. The results show that the TSS is highly correlated with other pollutant parameters. The statistical regression models using TSS EMC have been developed to easily determine the EMC of other pollutant parameters.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.4
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• pp.119-122
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• 2008

The paved area like a road or bridge where having high impermeable rates were accumulated various non-point sources(NPS) by passing vehicles during dry season periods. They are flowed in the river continuous when it rains and could negative impact on environment. Therefore, this study monitoring NPS for two years and determinating for each pollutant EMCs and mass loading. The result shows that the EMC ranges are 11.60$\sim$230.90 mg/L for TSS, 4.58$\sim$31.90 mg/L for BOD, 1.86$\sim$9.20 mg/L for TN and 0.14$\sim$1.55 mg/L for TP. Also, the ranges of washed-off mass loading are determined to 0.78$\sim$18.01 kg/day for TSS, 0.47$\sim$1.17 kg/day for BOD, 0.00$\sim$0.01 kg/day for Pb and 0.01$\sim$0.06 kg/day for Zn.

• Journal of Environmental Science International
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• v.18 no.9
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• pp.1027-1033
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• 2009

For the assesment of pollutant loads, a monitoring has been conducted to identify hydrologic conditions and water quality of the Oenam watershed in Juam Lake, and the SWAT model integrated with GIS was applied to the watershed and evaluated for its applicability through calibration and verification using observed data. For the model application, digital maps were constructed for watershed boundary, land-use, soil series, digital elevation, and topographic input data of the Oenam watershed using Arcview. The observed runoff was 832.8 mm while the simulated runoff was 842.8 mm in 2003. The model results showed that the simulated runoff was in a good agreement with the observed data and indicated reasonable applicability of the model. In terms of nutrient load, the simulation results of T-N, T-P showed a similar trend to observed values. The observed T-N load was 10.8 kg/ha and the simulated T-N load was 7.6 kg/ha while the observed T-P load was 0.21 kg/ha and the simulated T-P load was 0.18 kg/ha. In general, SWAT model predicted observed runoff and loads of T-N and T-P after calibration with observed data in acceptable range. Overall, SWAT model was satisfactory in estimation of nutrient pollutant loads of the rural watershed.

• Korean Journal of Environmental Agriculture
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• v.27 no.1
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• pp.10-17
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• 2008

The objective of this study was to estimate the pollutant loads from paddy fields by cultivation practices using a non-point-sources models. One of them is CREAMS-PADDY model that was developed considering the water balance and mass balance of paddy fields. The CREAMS-PADDY model was applied to provide basic data to reduce runoff loadings under various scenarios such as various water management control and various fertilizer condition. The model was verified against T-N, T-P and runoff flow data collected during cropping periods at 2000. The model results agreed well with the measured data in verification. The results showed that the model could be used for estimating the runoff loadings from irrigated paddy fields by cultivation practices was possible. Comparison of simulated the standard height and the sluice management of T-N and T-P runoff loadings from paddy fields were +32.4%, +10.3% in 10 mm below the standard height, -29.2%, -35.9% in 20 mm above the standard height, 52.6%, 59.0% in 40 mm above the standard height, respectively. Comparison of simulated the standard fertilizer and the fertilizer control of T-N and T-P runoff loadings from paddy fields were -1.3%, -21.7%in reduction of conventional fertilizer 30%, -1.0%, -12.5% in reduction of standard fertilizer 30%, respectively. Therefore, reducing nonpoint-sources nutrient loading by reducing fertilization may not work well in the range of normal paddy rice farming practices, and instead it could be achieved by reducing surface drainage outflow.

• Journal of Korean Society on Water Environment
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• v.40 no.3
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• pp.131-139
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• 2024

This study investigated the chemical properties of Organic Soil Amendments (OSAs) made from organic waste. It also assessed the effectiveness of using these OSAs in the soil layer of Green Infrastructure (GI) to reduce stormwater runoff and non-point source pollutants. The goal was to improve the national environmental value through resource recycling and contribute to the circular economy transformation and carbon neutrality of urban GI. The OSAs used in this study consisted of spent coffee grounds and food waste compost. They were found to be nutrient-rich and stable as artificial soils, indicating their potential use in the soil layer of GI facilities. Applying OSAs to bio-retention cells and permeable pavement resulted in a reduction of approximately 11-17% in stormwater runoff and a decrease of about 16-18% in Total Phosphorus (TP) discharge in the target area. Increasing the proportion of food waste compost in the OSAs had a positive impact on reducing stormwater runoff and pollutant emissions. This study highlights the importance of utilizing recycled resources and can serve as a foundation for future research, such as establishing parameters for assessing the effectiveness of GI facilities through experiments. To enable more accurate analysis, it is recommended to conduct studies that consider both the chemical and biological aspects of substance transfer in OSAs.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.4
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• pp.209-221
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• 2006

The purpose of this study is to analyze the effects of climate change on the nonpoint source pollution in a small watershed using a mid-range model. The study area is a basin in a rural area that covers 384 ha with a composition of 50% forest and 19% paddy. The hydrologic and water quality data were monitored from 1996 to 2004, and the feasibility of the GWLF (Generalized Watershed Loading function) model was examined in the agricultural small watershed using the data obtained from the study area. As one of the studies on climate change, KEI (Korea Environment Institute) has presented the monthly variation ratio of rainfall in Korea based on the climate change scenario for rainfall and temperature. These values and observed daily rainfall data of forty-one years from 1964 to 2004 in Suwon were used to generate daily weather data using the stochastic weather generator model (WGEN). Stream runoff was calibrated by the data of $1996{\sim}1999$ and was verified in $2002{\sim}2004$. The results were determination coeff, ($R^2$) of $0.70{\sim}0.91$ and root mean square error (RMSE) of $2.11{\sim}5.71$. Water quality simulation for SS, TN and TP showed $R^2$ values of 0.58, 0.47 and 0.62, respectively, The results for the impact of climate change on nonpoint source pollution show that if the factors of watershed are maintained as in the present circumstances, pollutant TN loads and TP would be expected to increase remarkably for the rainy season in the next fifty years.