• 한국농공학회논문집
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• 제57권5호
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• pp.129-137
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• 2015

The objective of this study was to test the non-point source pollution (NPS) control by the vegetated ridge and silt fence through field monitoring. The experiment plots were established with three sizes which are 5 m width by 22 m length with 8 %, 3 % slope and 15m width by 15 m length with 6 % slope. Flumes with the floating type stage gages were installed at the outlet of each plot to monitor the runoff. For a rainfall monitoring, tipping bucket rain gage was installed within the experiment site. Water quality samples were monitored during the heavy rainfall occurred. The amount of rainfall from 4 monitored events ranged from 27.6 mm to 130 mm. The runoff reduction rate could vary depending on slope, soil, crop growth condition, rainfall amount, rainfall intensity, antecedent moisture condition, and many other factors. The runoff from vegetated ridge and silt fence treatment plots was 24.05 % and -8.28 % lower than that from control plot, respectively. The monitoring results showed that the average pollution loads reduced by vegetated ridge compared to control were BOD 36.62~53.60 %, SS 40.41~73.71 %, COD 39.34~56.41 %, DOC 49.08~53.67 %, TN 26.74~67.23 %, and TP 52.72~91.80 %; by silt fence compared to control were SS 41.73 %, COD 1.93 %, and TN 2.38 %. The paired t-test result indicated that the vegetated ridge and silt fence were statistically significant effect in SS load reduction, with a 5 % significant level. Monitored results indicated that vegetated ridge and silt fence were both effective to reduce the pollutant from the field surface runoff.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2002년도 학술발표회 발표논문집
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• pp.417-420
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• 2002

VFS는 침전물, 영양물질, 농약 등이 지표수로 유입하는 것을 감소시킬 수 있는 유용한 BMP이다. VFS의 식생의 종류는 목초, 관목 및 나무가 있으나 우리 나라와 같이 비점원오염 관리를 목적으로 하는 경우에는 목초가 가장 적당한 식생이다. VFS의 효과는 토양특성, 배수면적, 지형과 지변경사, 식생의 품질과 토지이용과 기후에 지배된다. 그리고 주기적인 VFS의 관리는 비점원오염을 관리하는데 중요한 요소이다. 식생의 정화능력을 이용한 VFS는 비점원오염 관리에 매우 효과적인 것으로 밝혀지고 있다. 그러나 VFS 독자적인 적용보다는 저류지와 같은 다른 기법과 동시에 적용하는 복합적인 관리대책을 강구하는 것이 더 효과적이다. VFS의 폭은 토양 특성, 배수면적, 지면 경사, 식생의 종류, 토지 이용도 등에 따라서 다르나 대체로 10m 정도가 적당할 것으로 사료된다. 그러나 보다 신뢰성 있는 VFS의 설계기준은 실제 시공과 사후 효과분석을 통하여 많은 자료를 축적한 후에 얻을 수 있을 것이다.

• 한국습지학회지
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• 제15권3호
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• pp.387-396
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• 2013

비점오염원은 배출원, 유출경로 및 배출량이 명확하지 않아 관리에 많은 어려움이 있다. 최근 들어, 비점오염 관리를 위해 다양한 비점오염저감시설들에 대해 개발 및 연구 되고 있다. 또한 비점오염시설의 정확한 평가를 위해 다양한 효율산정 방법들이 제시되고 있다. 본 연구에서는 강우 시 식생수로 길이별 모니터링 결과를 토대로 식생수로의 길이가 저감효율에 미치는 영향에 대해 연구를 수행하였다. 또한 식생수로 길이별 저감효율을 다양한 방법으로 산정하여 효율 산정방법에 따른 차이를 비교하고자 하였다. 효율 산정 방법으로는 ER, SOL, ROL, ROF, SOLF, ROLF 방법을 이용하여 분석하였다. EMC 분석결과 유입 및 유출량의 농도차이가 유기물질이 염양염류에 비하여 크게 나타났다. 식생수로 길이에 따른 효율 분석 결과 식생수로 유입부에서 효율이 급증하고, 이 후에는 효율 증가가 점차 감소하는 것으로 나타났다. 이는 식생수로 전단에 설치된 저류지에 의한 것으로 판단된다. 식생수로의 저감효율을 확보하기 위해서는 식생수로의 길이가 최소 30m이상으로 충분히 확보되어야 한다. 또한 식생수로의 경제적이고 효율적인 설계를 위해선 단순한 효율분석이 아닌 식생수로 최소 길이에 대한 연구가 필요하다.

• 한국물환경학회지
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• 제25권6호
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• pp.972-978
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• 2009

This study modifies the present total maximum daily load (TMDL) system of Ministry of Environment and applies to the Anyangcheon watershed. Hydrologic Simulation Program-FORTRAN (HSPF) model is used to simulate both runoff and non-point source pollution, simultaneously, instead of QUAL2E. The drought flow (355th daily flow) is proposed for the target water quantity since it is easier to satisfy low flow (275th daily flow) for the target water quality than drought flow. The increase of discharge is more than the increase of pollutant load except for the period under low flow. The measured unit loads for non-point source are used to consider the regional runoff characteristics. The measured water quantity and quality data are used since the ministry of environment supports only water quality. This analysis results show some reasons for the improvement of the present TMDL system of Korea.

• 한국물환경학회지
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• 제27권4호
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• pp.499-508
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• 2011

We analyzed the variations of water quality with flow regime alterations to determine the characteristics of the stream where the stream management is considerably difficult due to the high variability of the flow rates. In this study, both flow rates and water qualities were monitored at the tributaries, 34 in count, of both Geum River and Sabgyo Lake Basins. The variation of water qualities were divided into 2 types, based on their stream flow rates, known as Type I and Type II. If the water quality of a stream increases during low flow rate periods compared with high flow rate periods, it is classified as Type I; if the water quality of the stream increases during high flow rate periods compared with low flow rate periods, it falls under Type II. The analysis for the variations of water qualities, of all 43 basins, resulted to 24 basins under Type I and Nineteen 19 basins under Type II. The variations of water qualities were analyzed first by using Regression Analysis followed by Statistical Analysis. The average slope of the variations of water qualities and the slope of the standard deviations were 0.00135 and 0.00477, respectively. The Probability Distributions of both Type I and Type II basins were 61.1% and 38.9%, respectively. The basin having a probability distribution of 61.1% and is also known as Type I, increases during periods of low flow rates, due to the presence of point sources. Therefore, the basin should be enforced with stream management. Before the stream management can be implemented in all streams falling under Type II, the sources of contaminants should first be estimated. These contaminants can be classified into two parts, the first is Point source pollution and the second is Non-point source pollution, where the Non-Point source pollution can be sub-divided into two types, with storm runoff and without storm runoff.

• 한국해양공학회지
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• 제33권6호
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• pp.597-606
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• 2019

Due to climate change, coastal areas are being flooded with torrential rain, typhoons, and tsunamis. In addition, non-point source pollutants (NPSs) that accumulated on the ground, streets, and buildings during the dry season are washed off by rain and stormwater runoff, which adds to the damage associated with environmental pollution, e.g., pollution that makes its way into the ocean. Recently, low impact development (LID) has been considered as a means of controlling water circulation and NPSs. In the coastal area, permeable blocks have been constructed mainly to reduce the flood damage caused by waves. Some important design factors that must be considered to ensure long-term performance are the permeability coefficient, clogging, and the efficiency of the removal of total suspended solids (TSS), but currently there are no standardized design criteria or testing techniques that are used worldwide. Herein, we analyzed the permeability coefficient and the TSS removal efficiency tendency according to the permeability area ratio with an easily-detachable, permeable block filled with calcinated yellow soils as the filter media. Our lab-scale tests indicated that, when the permeability area ratio was 25%, the reduction of the permeability coefficient after clogged was 11%, which was a significant decrease compared to other cases. Permeability persistence increased when the permeability area ratio increased from 50% to 75%. The TSS removal efficiency decreased as the permeability area ratio increased. Our pilot-scale test indicated that the TSS removal efficiency was more than 80% higher in all cases. We also found that the permeability persistence was excellent as the permeability area ratio increased, and, in actual construction, it is effective to set 5.3% of the total area as permeable area in terms of permeability and economic feasibility.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1999년도 국제 심포지엄 Proceedings of International Symposium on 친환경농업과 기계화방향
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• pp.137-159
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• 1999

Over the last three decades, Korean farming system has been directed to maximum agricultural production and to increase farmer's income through adoption of high-yielding crop varieties and high input of agrochemicals . These farming practices have resulted in problems of water-quality deterioration, soil degradation , and food safety. At present, over 40 million tones of animal waste are bing produced annually, which amounts to disposing the waste at the annual rate of 20 tones per ha in the total area of farming land in Korea. Nearly a half of total available water resources is used as irrigation water predominantly for rice paddy field. Thus, non-point source contamination of the water resources has been linked to agriculture across the nation. However, the extent to which agriculture contributes to the water quality is not fully known. Recently, Korean government provided various institutional measures to reduce the negative impacts of agricultural practices on the environ ental quality, and the Agricultural Environment Act was also passed by the legislature in 1998 and became effective January 1999. This Act does not cover the broad spectrum of the sustainable agriculture ; thus, the limited incentives within this Act are arguably ineffective to control the non-point source pollution. Recently new bulk blending of fertilizers(BB fertilizer) are bing produced (100, 000 tones in 1998) with Government subsidies. The BB fertilizers are to balance N-P-K ratio in the soils . Although the use of the BB fertilizers are encouraged with Government subsidies, non-point source pollution is still serious and will become worse. Precision farming is regarded as a new means for sustainable agriculture. It is a new technology that modifies the existing techniques and incorporates new one such as GIS, GPS , differential applicator to produce a new set of tools for the farmer to use. Precision farming, however, has constraints for individual farming practices. For exam le , farm size or parcel unit of each farmer is too small to adopt the precision agriculture on farmhouse-hold bases and farmer's ability to adopt the new technology is limited. However, it would be appropriate to establish local or regional cooperatives to operate such a precision farming system. It is recommended that Government provide sufficient incentives to help establish local and/or regional cooperatives.

• 한국물환경학회지
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• 제37권2호
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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.

• 상하수도학회지
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• 제33권1호
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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.

• 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.