• The Journal of the Korea Contents Association
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• v.16 no.1
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• pp.140-150
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• 2016

This study aims to investigate the effect of vegetation type, length of vegetative filter strip, and rainfall on trapping efficiency of the non-point source water pollution. Numerical experiments are carried out using VFSMOD-w. It is known from this study that the vegetation having the same value of revised Manning roughness coefficient shows the similar trapping efficiency in VFSMOD-w. When the length of vegetative filter strip increases twice, the trapping efficiency increases negligibly small under the same condition of rainfall. From this finding, it is also known that most of sediment are removed within a certain length of vegetative filter strips. It is concluded that the installation of vegetative filter strip is determined under the consideration of the rainfall characteristics, space of vegetation, and length of vegetative filter strip.

• Journal of Korean Society of Rural Planning
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• v.19 no.4
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• pp.319-327
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• 2013

The objective of this research was to develop a relational database management system(RDBMS) to collect, manage and analyze data on agricultural non-point source(NPS) pollution. The system consists of the relational database for agricultural NPS data and data process modules. The data process modules were composed of four sub-modules for data input, management, analysis, and output. The data collected from the watershed of the upper Cheongmi stream and Geunsam-Ri were used in this study. The database was constructed using Apache Derby with meteorological, hydrological, water quality, and soil characteristics. Agricultural NPS-Data Management System(ANPS-DMS) was developed using Oracle Java. The system developed in this study can deal with a variety of agricultural NPS data and is expected to provide an appropriate data management tool for agricultural NPS studies.

• Journal of Korean Society on Water Environment
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• v.33 no.3
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• pp.247-255
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• 2017

This research was conducted to analyze removal efficiencies of non-point pollution source (NPS) in low impact development (LID) facilities with vegetation. In this research, removal efficiencies of NPS were calculated using rainfall monitoring data for 5 years in grassed swale (GS) and vegetative filter strip (VFS). TSS was greater than other pollutants, and it ranged 11.9 ~ 351.7 mg/L in GS and 12.8 ~ 350.7 mg/L in VFS. Outflow EMCs were reduced than inflow EMCs, overall removal efficiencies of NPS were 67 ~ 86% in GS and 63 ~ 91% in VFS. 50 % reduction efficiency of rainfall runoff was observed between inflow and outflow in each LID facility. TSS removal efficiency in GS and VFS was correlated with rainfall characteristics. The rainfall for TSS removal efficiency over 50% was determined about 31 mm, 34 mm and average rainfall intensity was 3.0 mm/hr, 3.9 mm/hr in GS and VFS. Therefore, GS and VFS were regarded effective LID facilities as removal of pollutants and rainfall runoff. Also, this research result can be used as an important data for management of NPS.

• Journal of Wetlands Research
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• v.13 no.2
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• pp.161-169
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• 2011

The objective of this study was to evaluate the efficiency of a modified filtration system treating non-point source (NPS) pollutants. The developed Best Management Practice (BMP) technology was designed based on the geographical and climatic characteristics of the site. A lab-scale test experiment was conducted using three different hydraulic loading rates representing the first flush flow, average flow and overflow conditions during a rainfall event. Water quality analysis was performed on the water samples taken at the inflow, outflow and infiltration during the test experiment of the lab-scale BMP. Also, the water and mass balance at different hydraulic loading rates was determined. Results from the lab-scale test experiment showed that the lab-scale BMP had a high removal efficiency of 80-90% for all NPS pollutants. The overflow test condition obtained the lowest removal efficiency among the hydraulic loading rates because it gave less opportunity for the pollutants to be filtered and retained inside system. The infiltration ratio was approximately 1 % of the inflow and outflow. Increasing the infiltration ratio requires technical approach of soil amendment where the BMP is installed.

• Journal of Wetlands Research
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• v.14 no.2
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• pp.181-192
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• 2012

Dae Dong Stream basin has been selected and operated as a representative experimental basin of UNESCO IHP since year 2007. It is located at Daejeon Metropolitan city, Korea and hydrologic data such as precipitation, runoff, and water quality have been being collected and provided after establishing the monitoring plan as an experimental basin for city/disaster prevention. In this study, runoff characteristics for non-point sources of rainfall-runoff process from urban stream basins were analyzed using the flow and water quality data measured during the year 2011. As an operation result for the test subjected basin, rating curves at Panam Bridge and at Chulgap Bridge were prepared, and to compare runoff characteristics of non-point source by precipitation, by estimating the Event Mean Concentration(EMC) for 10 water quality items, runoff characteristics of non-point source per different observation points as per the precipitation, antecedent rainfall, and land utilization status were analyzed.

• Journal of Korean Society on Water Environment
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• v.24 no.1
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• pp.69-77
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• 2008

This study was conducted to know the characteristics of agricultural non-point source pollutants runoff by rainfall events at the upper catchment of Goseong reservoir in Gonjy city, Chungnam Province. For this study, the monitoring sites of the research catchment were set nineteen during the research period (between June 2005 and October 2006). Average runoff coefficient were observed 0.51 in 2005, 0.71 in 2006, respectively. The correlation coefficient (r) between the rainfall and peak-flow was investigated 0.787. By rainfall events, the water quality of the sites were shown like this : BOD 0.555~9.60 mg/L, T-N 0.01~13.50 mg/L, T-P 0.002~2.952 mg/L, and SS N.D~820.0 mg/L. The strong rainfall intensity was the most important factor of the soil erosion. The gabs of the arithmetic mean concentrations and the flow weighted mean concentrations were observed as the followings : BOD 0.0~29.2%, T-N 0.1~11.4%, T-P 0.4~95.2%, and SS 1.7~57.0% in 2005, and BOD 1.0~11.9%, T-N 0.7~7.3%, T-P 9.9~36.5%, and SS 6.6~36.5% in 2006, respectively. The BOD pollution load was 2,117 kg (36% of the total BOD loading of survey periods) while, T-N was 3,209.0 kg (27.9% of the total T-N loading of survey periods), T-P was 136.4 kg (37.4% of the total T-P loading of survey periods) and SS was 72,733.8 kg (51.8% of the total SS loading of survey periods) in the year 2005. In case of 2006, BOD load was 1,321.7, T-N was 2,845.8, T-P was 42.9, and SS was 16,275.8 kg, respectively.

• Journal of Korean Society on Water Environment
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• v.37 no.2
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• pp.103-113
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• 2021

In this study, an Excel-based model (ROADMOD) was developed to estimate pollutant loading from the road and evaluate BMPs. ROADMOD employs the Chezy-Manning equation and empirical expression for estimating surface runoff, and power function for pollutant buildup, and exponential function for pollutant washoff in SWMM. The results of model calibration for buildup and washoff using observed data revealed a good match between the simulation results and the observed data. The long-term surface runoff and sediment simulated by ROADMOD demonstrated a good match with those by SWMM with 2 ~ 14% of relative error. The shorter sweeping interval (within 8 days) remarkably decreased sediment loads from the road. It was found that the effect of reducing sediment loads from the road was greatly affected not only by the sweeping interval but also by sweeping on the day before a rainfall event. The 48% of removal efficiency of sediment loads from the road was achieved with 26 times of road sweeping per year when sweeping was performed on the day before the rainfall event. A 4-day sweeping interval showed similar removal efficiency (48%) with 96 times of sweeping per year. It is considered that the road sweeping on the day before a rainfall event could maximize the effect of reducing the non-point source pollution from the road with minimization of the number of road sweeping. So, the road sweeping on the day before a rainfall event can be considered as one of the useful and best management practices (BMPs) on road.

• Journal of Korean Society of Water and Wastewater
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• v.33 no.1
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• pp.79-86
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• 2019

In order to measure the filtration characteristics of a cotton ball shape filter, the experiments of suspended solids(SS) surrogate material selection and filtration performance have been carried out in this study. Between the two materials of powdered activated carbon(PAC) and powdered red-clay, PAC is more suitable surrogate material in terms of experimental criteria and particle size distribution in the non-point source pollutants removal system. As a result of the filtration experiments with the cotton ball shape filter, the initial headloss was about 8 cm, and the headloss slightly increased over filtration time. The Kozeny-Carman equation was used to analyze the changes of pressure and porosity during the filtration. The initial porosity was calculated as 0.945 and it decreased to 0.936 at the end of design filtration time. As the filtration continued, the SS concentration of the filtered water gradually increased and the SS removal rate gradually decreased. When the SS target removal efficiency is assumed to be 80%, the cumulative SS removal capacity is expected as $28.8kg/m^2$. This means the volume loading rate of the cotton ball shape filter can be $115m^3/m^2$ when the typical SS concentration of non-point source water pollution is assumed as 250 mg/L.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.7
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• pp.65-72
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• 2006

Event mean concentration (EMC) of nitrogen (N) and phosphorus (P) is primary information for non-point source pollution assessment of a watershed. The EMCs for various types of agriculture such as dairy and crop farming under different climate and geologic conditions are not fully investigated. A diary- and cropfarming complex agricultural watershed in Piedmont region in Maryland, USA has been monitored for 10 years as a section 319 national monitoring program of US EPA. Dairy manure was the main source of fertilizer for crop farming in this watershed. Observed mean concentrations of N and P for each event were analyzed. Distribution of EMCs for N and P showed a wide range of variations. Representative EMCs of T-N and $NO_{3}-N$ tended to be higher than those reported for other agricultural watersheds. This study confirmed that site-specific EMC information for various agricultural practices is required for better assessment of non-point source pollution using EMC method.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.4
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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.