• 한국농공학회논문집
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• 제50권2호
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• pp.65-71
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• 2008

A monsoon season monitoring data from June to September, 2005 of a small forested watershed located at the upstream of the North Han River system in Korea was conducted to analyze the flow variations, the NPS pollutant concentrations, and the pollution load characteristics with respect to sampling frequencies. During the 4-month period, 1,423 mm or 79.2% of annual rainfall(1,797 mm) were occurred and more than 77%, 54% and 68% of annual T-N, $NO_3$-N and T-P loads discharged. Flow rate was continuously measured with automatic velocity and water level meters and 58 water quality samples were taken and analyzed. It was analyzed that the flow volume by random measurement varied very widely and ranged from 79% to 218% of that of continuous measurement. It was recommended that flow measurement of small forested watersheds should be continuously measured with automated flow meters to precisely measure flow rates. Flow-weighted mean concentrations of T-N, $NO_3$-N and T-P during the period were 2.114 mg/L, 0.836 mg/L, and 0.136 mg/L, respectively. T-N, $NO_3$-N and T-P loads were sensitive to the number of samples. And it was analyzed that in order to measure the pollution load within the error of 10% to the true load, the rate of sampling frequency should be higher than 89.7% of the sample numbers that were required to compute the true pollution load. If it is compared to selected foreign research results, about 10 water samples for each rainfall event were needed to compute the pollution load within 10% error. It is unlikely in Korea and recommended that thorough NPS pollution monitoring studies are required to develop the standard monitoring procedures for reliable NPS pollution quantification.

• 한국농공학회논문집
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• 제57권4호
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• pp.51-59
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• 2015

Various Best Management Practices (BMPs) have been suggested to reduce soil erosion and non point source (NPS) pollutant loads from agricultural fields. However, very little research regarding water quality improvement with No-till (NT) has been performed in Korea. Thus, effects of NT were investigated in this study. The objective of the study was to investigate the effect of NT on the surface runoff and sediment discharge in a field. Eight experimental plots of $5{\times}30m$ in size and 3 % or 8 % in slope prepared on gravelly sandy loam soil were treated with Conventional-till (CT) and NT. Runoff and NPS pollution discharge were monitored and compared the treatments. The amounts of rainfall from 13 monitored events ranged from 28.7 mm to 503.5 mm. The runoff amount was reduced by 17.6~59.2 % in 3 % NT and 29.6~53.2 % in 8 % NT. The average NPS pollution loads of the 3 % NT plots and 8 % NT plot were reduced about 45.1~89.2 % and 47.7~98.0 % compared to those of the CT plots, respectively. This research revealed that NT can reduce the NPS pollution loads substantially as well as increase the crop yield. Runoff and NPS pollution loads reduction by NT method could be contribute to improve the water quality of streams in agricultural regions.

• 한국농공학회논문집
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• 제55권5호
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• pp.1-7
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• 2013

The objective of this research was to experimentally test the effect of tillage methods on the reduction of runoff, non-point source (NPS) pollution load, sediment and discharge under a rainfall simulation. We used the runoff plots of $5m{\times}30m$ ($L{\times}W$) in size. Experimental treatments were conventional tillage (CT), CT-rice straw bundle (CT-RSB) and two no-till (NT) plots; slope of 3 % or 8 % ; and rainfall intensity of 30 mm/hr. The rainfall simulation was conducted to three times. The time to initial runoff from NT plots was less than that from CT plots regardless of the slope and it was delayed about 65~90 % compared to that of CT plot. And sediment discharge of 8 % slope reduced to 55 % compared to CT plot. But the sediment discharge was not occurred at 3 % slope. The NT and CT-RSB methods have a great possibility of reducing runoff and NPS pollution loads. Runoff rate of NT plots was significantly lower than those of CT plot. The average NPS pollution loads of the NT plots and CT-RSB plot reduced about 55~80 % and 2.1~40 % compared to those of the CT plots, respectively. It was also shown that runoff and NPS pollution loads reduction by NT method could be very significant and contribute to improve the water quality of streams in agricultural regions. It was concluded that the use of NT method on agricultural fields could reduce soil erosion and muddy runoff significantly and help improve the water quality and aquatic ecosystem.

• 한국물환경학회지
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• 제26권3호
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• pp.474-481
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• 2010

This study was conducted to describe the characteristics of Non-point source (NPS) Pollution discharge from a coal mining area in Korea. The study areas is located on the Dogye site, Samchuk, Kangwon Province Coal Corporation and the Jangsung site, Taebaek, Kangwon Province Coal Corporation. The monitoring system was installed at a drainage channel and water samples and rainfall events were collected during March 2008 to February 2009. The collected water samples were analyzed with respect to SS, BOD, $COD_{Cr}$, $COD_{Mn}$, T-N, T-P, and TOC, respectively. It was observed that the runoff and water quality were largely influenced by mine drainage. Also a significant relationship was observed from the correlation between flow and water quality, flow and NPS. And estimated Event Mean Concentration (EMC), NPS pollution loads were Dogey coal mine and Taeback coal mine respectively. As the study progresses in the future, runoff and pollution loads will be updated.

• 한국농공학회논문집
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• 제54권6호
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• pp.89-99
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• 2012

An upland monitoring was conducted for about 4 years with respect to the water and quality of rainfall-runoff. The objective was to characterize of runoff and nonpoint source (NPS) pollution from a sandy field with 4.5 % in slope under balloonflower (2008-2010) and potato (2011) cultivation. Balloonflower was cultivated without any surface cover but potato was grown under plastic mulching. Runoff rate, EMCs and NPS pollution loads were estimated. The first flush effect was evaluated, and the correlation coefficient among the selected water quality indices were analyzed. Average rainfall size was higher by 2.3 mm when balloonflower was cultivated but average runoff rate was higher by 0.02 when potato was cultivated due to the plastic mulching. EMCs monitored from balloonflower field were higher than potato field except SS and TN, but all NPS pollution loads of potato field were 2.1~22.9 times greater than balloonflower field because of larger runoff volume. As a result of first flush effects, balloonflower and potato field were more influenced by increasing of accumulated rainfall and rainfall intensity rather than first flush. In the result of correlation analysis, there were no evident correlations between runoff and water quality indices. However, there were obvious correlations between SS and the other indices except TN. As a result of this study, it was thought that perennial balloonflower crop could help reduce runoff and NPS pollution loads but annual crop with plastic mulching increase them.

• 한국물환경학회지
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• 제28권3호
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• pp.436-443
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• 2012

This research was focused on the effect of rice straw and rice straw mat on the reduction of upland field non-point source (NPS) pollution discharges. Six experimental plots of $5{\times}22m$ in size and 3% in slope prepared on gravelly sandy loam soil were treated with control, rice straw cover and rice straw mat cover. Radish in Spring growing seasons were cultivated. NPS pollution discharge was monitored and compared with respect to the treatments. The surface cover rate of rice straw and rice straw mat right after the treatments was 64.7% and 73.7%, respectively. Rainfall of the 16 monitored events ranged from 12.8 mm to 538.2 mm. Runoff coefficient of the events was 0.01~0.67 in control plot, 0~0.63 in rice straw plot and 0~0.45 in rice straw mat plot. The reduction of runoff compared to the control plot was 5.4~99.7% in rice straw plot and 32.9~100% in rice straw mat plot. The reduction of NPS pollution load was 52.0% for SS, 28.5% for T-N and 35.2% for T-P in rice straw plot and 79.8% for SS, 68.3% for T-N and 53.3% for T-P in rice straw mat plot. This research revealed that rice straw mat cover on the soil surface could not only increase the crop yield and farmer's income but also reduce the NPS pollution loads significantly.

• 한국농공학회논문집
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• 제55권4호
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• pp.21-28
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• 2013

The objective of the study was to investigate the effect of rice straw mat, rice straw mat with PAM (Polyacrylamide) and gypsum addition on surface runoff and sediment discharge in field. Six experimental plots of $5{\times}22m$ in size and 3 % in slope prepared on gravelly sandy loam soil were treated with control, rice straw mat cover with gypsum and rice straw mat cover with gypsum and PAM. Radish in Spring and Chinese cabbage in autumn growing seasons were cultivated. Non point source (NPS) pollution discharge was monitored and compared among the treatments. Rainfall of the 10 monitored events ranged from 17.0 mm to 93.5 mm. Runoff coefficient of the events was 0.005~0.239 in control plot, 0~0.176 in rice straw plot with gypsum and 0~0.046 in rice straw mat plot with gypsum and PAM. When compared to the control plot, the runoff amount was reduced by 10.4~100 % (Ave. 60.8) in rice straw plot with gypsum and 80.7~100 % (Ave. 96.7 %) in rice straw mat plot with gypsum and PAM. The reduction of NPS pollution load was 54.6 % for BOD5, 71.5 % for SS, 41.6 % for TN and 61.4 % for T-P in rice straw with gypsum plot and 91.9 % for BOD5, 92.0 % for SS, 88.0 % for TN and 88.5 % for T-P in rice straw mat with gypsum and PAM plot. This research revealed that rice straw mat cover with soil amendments on the soil surface could not only increase the crop yield but also reduce the NPS pollution loads substantially.

• 한국농공학회논문집
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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.

• 한국농공학회논문집
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• 제57권5호
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• pp.61-67
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• 2015

Effect of tillage on time of initial runoff, runoff coefficient, NPS pollution load, soil erosion and crop productivity were studied. Eight runoff plots of $5{\times}30m$ on loamy sand field that were 4 respective plots of 3 % and 8% slope were prepared. Treatment included conventional tillage (CT) and no-till (NT). Time of initial runoff from NT retarded between 247~261 % compared with that from CT. Under 3% slope, runoff coefficient in NT was 63.5 % lower than that in CT. The reduction under 8 % slope was 61.7 %. Differences in runoff reduction between 3% and 8% plots were not significant. NT could reduce more than 60 % of NPS pollution and between 50~85 % of sediment if compared with CT. Productivity of NT was also shown that it was not lower than that of CT. It was expected that the results could be used as a fundamental data for estimating a reduction load in Korea TMDL from a no-till BMP on loamy sand agricultural fields.

• 한국물환경학회지
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• 제39권4호
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• pp.316-328
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• 2023

In this study, the characteristics of nonpoint pollutant outflow and contribution rate of pollution in Songya-stream mainstream and tributaries were analyzed. Further, water pollution management and improvement measures for pollution-oriented rivers were proposed. An on-site investigation was conducted to determine the inflow of major pollutants into the basin, and it was found that pollutants generated from agricultural land and livestock facilities flowed into the river, resulting in a high concentration of turbid water. Based on the analysis results of the pollution load data calculated through actual measurement monitoring (flow and water quality) and the occurrence and emission load data calculated using the national pollution source survey data, the S3 and S6 were selected as the concerned pollution tributaries in the Songya-stream basin. Results of cluster analysis using Pearson correlation coefficient evaluation and Density based spatial clustering of applications with noise (DBSCAN) technique showed that the S3 and S6 were most consistent with the C2 cluster (a cluster of Songya-stream mainstream owned area) corresponding to the mainstream of Songya-stream. The analysis results of the major pollutants in the concerned pollution tributaries showed that livestock and land pollutants were the major pollutants. Consequently, optimal management techniques such as fertilizer management, water gate management in paddy, vegetated filter strip and livestock manure public treatment were proposed to reduce livestock and land pollutants.