• Journal of The Korean Society of Agricultural Engineers
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• 제56권5호
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• pp.89-99
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• 2014

The goal of this study was to evaluate sediment reduction effects of VFS (vegetative filter strip) applied for Iksan area in Saemangeum watershed. This study simulated runoff and sediment load from different types of uplands using VFSMOD-W. The general upland characteristics of the study area was investigated to build reasonable scenarios of the simulation. The simulation scenarios were designed by various areas, shapes, and slopes of uplands. Grass mixture was selected as VFS vegetation and the size of VFS was fixed as 10 % of uplands area. Additionally 50mm, 100mm, 150mm of daily rainfall were applied for the runoff and sediment simulation. As results, the calculated runoff and sediment loads were obtained $20.7{\sim}1,030.6m^3$ and 568.4~675,731.4 kg for the range of 0.1~1.0 ha of uplands with 7 % and 15 % slopes. The reduction effects on runoff and sediment were obtained 5~10 % and 21.0~47.7 % respectively from VFS applications. The VFSMOD-W simulations showed that runoff tended to increase as upland area and amount of rainfall increased while sediment increased when slope, length and area of uplands and amount of rainfall increased. These results indicated that rainfall amount and upland size are the critical factors for the generation of runoff and sediment load. In order to support this conclusion, further studies such as, long term monitoring, field experiments, and to calibrate and evaluate the model are necessary.

• Journal of Korean Society on Water Environment
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• 제34권3호
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• pp.308-315
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• 2018

SWMM-LID was calibrated with flow monitoring data in LHI to evaluate runoff after LID application. The flow rate in the B basin was estimated to be 0.94 and 6.15 for O/S and $D_v$, respectively. In the A and C basins, the difference between the observed and simulated data was greater than in the B basin. As a result of runoff reduction efficiency by the application of LID facilities, the change of infiltration increased from 34.6 % to 45.8 % in the entire watershed, and the runoff decreased from 58.8 % to 46.3 %. In the runoff reduction of each LID facility, rain garden E showed the highest effect with 99.9 % and bioretention B showed the lowest effect with 27.5 %. In order to evaluate the efficiency of each LID facility, a comparison is made between the pore volume (V) of the LID and the catchment area (A). The runoff showed a runoff reduction effect of about 70 % above the 0.1 volume/area (V/A) value. As a result of examining the runoff reduction with LID facilities by the LID module of SWMM, a reasonable design is possible by reflecting the appropriate LID volume to drainage area.

• Journal of Environmental Science International
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• 제19권11호
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• pp.1375-1384
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• 2010

Growth in population and urbanization has progressively increased the loading of pollutants from nonpoint sources as well as point sources. Especially in case of road regions such as city trunk road, national road and highway are rainfall and pollutants runoff intensive landuses since they are impervious and emit a lot of pollutants from vehicle activity. This research was conducted to investigate the nonpoint sources concentration and quantifying stormwater pollutants which are contained in rainfall runoff water. Three different monitoring sites in Jinju and Changwon city were equipped with an automatic rainfall gauge and flow meter for measuring rainfall and the volume of rainfall runoff. In the case of average EMC value, city trunk road was shown the highest value in target water quality items like as BOD, COD, SS, TN and TP. Or the amount of runoff loads by water quality items showed the highest value in city trunk road. And runoff load in city trunk road was 43.8 times high value compared to highway by value of city trunk road $356.7 mg/m^2$, highway $8.150 mg/m^2$, national road $19.99 mg/m^2$ in the case of BOD.

• Journal of Korean Society on Water Environment
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• 제26권3호
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• pp.413-419
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• 2010

A silica mine monitoring was conducted from March to December in 2008 to measure rainfall, runoff amounts and pollution loads. A total of 13 rainfall-runoff events were measured and analyzed with respect to runoff ratio, pollutant concentration and load, and initial flush. Over rainfall-runoff events, 95% confidence range of SS concentration was 942.5~2,056.2 mg/L. Other measured water quality indices also showed relatively large variation. This wide concentration variation was thought to be caused by the bare working ground of the mine that was used to store, process and transport the mined silica. Total pollution load of the 13 rainfall-runoff events was SS 17,901 kg/ha, $COD_{Cr}$ 160.9 kg/ha, $COD_{Mn}$ 111.24 kg/ha, BOD 79.6 kg/ha, T-N 13.8 kg/ha, T-P 3.5 kg/ha, and TOC 39.3 kg/ha. Initial flush was not well observed except SS. Very high SS concentration and load was occurred when rainfall was large. Therefore, it was recommended to manage the bare ground not to discharge excessive pollutants during wet days by covering the ground or constructing runoff treatment systems such as a sediment basin.

• Journal of Korea Water Resources Association
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• 제39권11호
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• pp.905-914
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• 2006

For an accurate rainfall-runoff simulation in the river basin, not evaluation of runoff model but accurate runoff data are very important. In this study, SSARR model was applied to the Geum River basin and these results are compared with runoff data observed at the Gongju gauging station. The model results didn't good fit the discharge data determined from the rating curve at Gongju gauging station during normal and dry season, especially. For the reliability analysis for the existing rating curve, we observed new stream discharge set from 2003 to 2005. We also estimated long term runoff data from the base flow separation method and defined the hydraulic characteristics. The results show that the new observed stream discharge is similar to the rainfall-runoff model results but existing rating curve seems to be overestimated about 10-20% during normal and dry season. We found that the continuous monitoring and update for the existing rating curve at the gaging station are needed for accurate estimation of runoff data.

• Journal of Korean Society on Water Environment
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• 제25권4호
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• pp.615-623
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• 2009

The research of the determination of event mean concentration (EMC) was focussed combined sewer overflows and highway runoff in korea. But those of non-urban areas are few. In this study, EMC and unit loading on land use types in Nogok watershed were estimated by runoff loading of non-point source (NPS) on non-urban area. Two monitoring sites were equipped with an automatic velocity meter, flow meter, and water sampler. Monitoring was conducted at two monitering site during the rainy season. The results show that the EMC ranges in forest land use are 1.3~2.6 mg/L for BOD, 2.0~16.1 mg/L for SS, 0.1~2.1 mg/L for TN, and 0.12~0.49 mg/L for TP. The unit loading of NPS in this study was difficult to compare directly with that used conventionally because of the difference of field investigation. In near future, it needs to conduct more systematic and long-term research about NPS within the watershed. The results of this research can be used to estimate the total pollution load management system (TPLMS) program in korea.

• Water for future
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• 제28권3호
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• pp.175-186
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• 1995

Characteristics of runoff and groundwater qualities from a pasture and field were investigated. Flumes and monitoring wells were installed and water qualities of $NO_3$-N, TP and TKN were monitored from Aug. 1993 to Aug. 1994. Runoff from the pasture which was a sandy soil with cobbles mostly formed with seeping water at the bottom of it. But once overland flow occurred because of heavy rainfall, runoff increased sharply. $NO_3$-N concentration in pasture runoff was relatively stable ranging between 0.241-3.962mg/l. TP and TKN concentrations were stable but sharply increased once overland flow occurred. $NO_3$-N concentration in pasture groundwater was relatively stable regardless of depth of monitoring wells but TP and TKN concentrations were smaller in deeper wells. Runoff from the field which was flat and covered well with Sudan grass and surface residue was relatively small and $NO_3$-N, TP and TKN concentrations in runoff were stable and seemed unaffected by flow rate. $NO_3$-N concentration in field groundwater increased at the rate of 2.2mg/l per 100 m during a growing season as groundwater flows through the field. No significant differences in TP and TKN concentrations between the upper and lower areas in field groundwater were detected.

• Journal of The Korean Society of Agricultural Engineers
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• 제55권2호
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• pp.29-36
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• 2013

The objective of the research was to describe the effect of straw mat cover and soil amendments on the reduction of runoff and non-point source load from steep sloped highland agricultural fields. Four $5{\times}30$ m plots on sandy loam soil with 28 % slope were prepared. Experimental treatments were bare (control), rice straw mat cover (3,000 kg/ha) (S), PAM (5 kg/ha)+Gypsum (1 ton/ha) (PG) and rice straw mat cover+PAM+Gypsum (SPG). A variety of lettuce was cultivated and runoff was monitored during a growing season in 2011. Natural monitoring was conducted to three times. Runoff rate of S, PG and SPG plots were significantly lower than those of control plot. Especially, the runoff rate is zero in SPG plot at a first rainfall events. The reduction rate of runoff from the S, PG and SPG plots was 30.8 %, 29.0 % and 81.8 % compared to control plots, respectively. The reduction rate of NPS pollution load of S, PG and SPG was ranged of 50~90 %, 30~70 % and 90~100 %, respectively. Yield of lettuce from S, PG and SPG plots was respectively 400 (567 kg/ha), 320 (453 kg/ha) and 760 (1,067 kg/ha) that of compared to control plots greater than that from control plots (140 kg/ha). We speculated that the experimental treated plots could hold more nutrients and moisture than the control and helped the crop grow healthier. When analyzing the above results, in terms of reduction of runoff and NPS pollution load and crop yields, SPG experimental treatment had the best effect. It was concluded that the use of rice straw mats cover and soil amendments on soil surface could not only reduce the NPS pollution loads in receiving waters but also help increase the crop yield.

• Journal of Korean Society on Water Environment
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• 제32권1호
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• pp.108-114
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• 2016

Sediment-laden water leads to water quality degradation in streams; therefore, best management practices must be implemented in the source area to control nonpoint source pollution. Field monitoring was implemented to measure precipitation, direct runoff, and sediment concentrations at a control plot and straw-applied plot to examine the effect on sediment reduction in this study. A hydrology model, which employs Curve Number (CN) to estimate direct runoff and the Universal Soil Loss Equation to estimate soil loss, was selected. Twenty-five storm events from October 2010 to July 2012 were observed at the control plot, and 14 storm events from April 2011 to July 2011 at the straw-applied plot. CN was calibrated for direct runoff, and the Nash-Sutcliffe efficiency and coefficient of determination were 0.66 and 0.68 at the control plot. Direct runoff at the straw-applied plot was calibrated using the percentage direct runoff reduction. The estimated reduction in sediment load by direct runoff reduction calibration alone was acceptable. Therefore, direct runoff-sediment load behaviors in a hydrology model should be considered to estimate sediment load and the reduction thereof.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.30-33
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• 2001

This study was carried out to estimate the runoff pollutant loadings for water quality management in Boryung freshwater reservoir watershed. The hydrological monitoring system were operated for water level measurement during $1999{\sim}2000$ and temporal variation of water quality constituents such as pH, EC, total nitrogen, total phosphorus were analysed, periodically. Monthly runoff volumes by TANK model and potential pollutant loadings calculated by unit method were compared with measured values.