• 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.

• 한국농공학회논문집
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• 제49권2호
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• pp.61-74
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• 2007

A mathematical modeling program called Hydrological Simulation Program-FORTRAN (HSPF) developed by the United States Environmental Protection Agency (EPA) was applied to Hwaseong watershed. It was run under BASINS (Better Assessment Science for Integrating Point and Nonpoint Sources) program, and the model was validated using monitoring data of $2002{\sim}2005$. The model efficiency of runoff ranged from good to fair in comparison between simulated and observed data, while it was from very good to poor in the water quality parameters. But its reliability and performance were within the expectation considering complexity of the watershed and pollutant sources. The nonpoint source (NPS) loading for T-N and T-P during the monsoon rainy season (June to September) was about 80% of total NPS loading, and runoff volume was also in a similar range. However, NPS loading for BOD ($55{\sim}60%$) didn't depend on rainfall because BOD was mostly discharged from point source (more than 70%). And water quality was not necessarily high during the rainy season, and showed a decreasing trend with increasing water flow. BASINS/HSPF was applied to the Hwaseong watershed successfully without difficulty, and it was found that the model could be used conveniently to assess watershed characteristics and to estimate pollutant loading including point and nonpoint sources in watershed scale.

• 한국물환경학회지
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• 제31권2호
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• pp.166-180
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• 2015

Pollutant in watersheds comes from two major sources which are NPS (nonpoint source pollution) and PS (point source pollution). Most of the pollutant can be treated by wastewater treatment plants. However, wastewater treatment plants may not be an appropriate practice to improve water quality for the watersheds with large portion of NPS pollutant and NPS pollution from direct runoff and baseflow has different characteristics. Therefore the practices to improve water quality need to be comprehensive for pollutants by both direct runoff and baseflow. Riparian buffer, one of practices to manage pollutant in watershed, has been applied to reduce pollutant not only from direct runoff but also baseflow. In this study, the scenarios for pollutant reduction by wastewater treat plants and the nitrogen reduction by riparian buffer were simulated using SWAT-REMM to suggest an effective plan for pollutant reduction from baseflow. Riparian buffer provided nitrogen reduction of 0.2~75.0% in YbB watershed and 38.0~47.0% in GbA watershed. The result indicates that riparian buffer is effective to reduce the pollutant especially from baseflow, and it suggested as suitable for the a watershed which WWTP discharge is not capable to reduce enough pollutant.

• 한국물환경학회지
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• 제27권5호
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• pp.572-579
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• 2011

We have examined the runoff characteristics of nonpoint source (NPS) in fields. Two monitoring sites were equipped with an automatic velocity meter and water sampler. Monitoring was conducted at fields 1 and field 2 during the rainfall event. Ten rainfall-runoff events were monitored and analyzed during the study period. The results show that runoff occurred if daily rainfall and intensity were higher than 40 mm and 1.6 mm/hr except a few extreme rainfall events with very high intensity. Runoff of field 1 was approximately twice of that of field 2. Event mean concentrations (EMC) and pollution load of analyzed water quality indices were also higher in field 2 than in field 1. Especially, TN load from field 2 was $75.4 mg/m^2$ and was about 5 times higher than that from field 1. Analysis of Pearson correlation coefficient of water quality parameter indicates that besides of TN all items in fields 1 have tight relationship respectively (p < 0.01). But those of fields 2 have a significant (p < 0.05). Estimating units loading of NPS, we suggested that variable such as soil texture, rainfall amount and intensity and slope were needed to be considered from agricultural landuses. The results of this study can be used as a basic data in the development and implementation of total maximum daily loads (TMDL) in Korea.

• 한국농공학회지
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• 제39권3호
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• pp.115-127
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• 1997

Nonpoint source (NPS) pollution from small watersheds has recently been brought into attention as a potential pollutant to streams and tnbutaries, as majority of them are experiencing water quality degradation. This necessiates the quantification of NPS loadings from agricultural and forested lands. And this study attempts to quantify daily loadings from forested and farm lands using hydrologic and water quality monitoring. The hydrologic monitoring program consists of five water level gauging stations along creeks and stream at the Banweol reservoir watershed having 1220 hectare in size. Water sam pies were taken and analyzeel periodically at the streamf low gaging sites and tributaries. Soil samples were also taken and the chemical constitutes analyzed. The primary results indicate that the major sources of pollution were small villages and dairy farms on the watersheds, constituting two-third of total nutrient loadings to the reservoir. However, the loadings from paddies and upland areas may cause a problem to the water quality of the reservoir and stream as the measured levels of total nitrogen and phosporus are not low enough to ignore. Further studies are needed to quantify the effects of landuses and treatments at a watershed scale.

• 한국농공학회논문집
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• 제64권1호
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• pp.65-77
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• 2022

Due to muddy water from the highland fields upstream of Soyangho Lake, the Mandae, Gaa, and Jawoon have been redesignated as NPS management areas. This study aims to evaluate the adequacy and supplementation points of the implementation plan by analyzing the operation status of muddy water generation and reduction facilities through on-site investigations by NPS management area to achieve the effective nonpoint pollution reduction goal in the implementation of the implementation plan established in 2020. The SS load calculated based on the survey results from July to October 2019 from 2017 showed a decreasen in 2019 compared to 2017. Both and the Jawoon were analyzed to have decreased. However, the amount of precipitation also decreased by about 27%, so it was judged that the effect of the reduction project was not significant. As a result of the detailed investigation of abatement facilities, about 86% of the 793 facilities installed in the management area were evaluated as 'good'. As a result of a detailed investigation by subwatersheds, subwatersheds 105 and 106 in the Mandae were analyzed as apprehensive subwatersheds. appeared to fall. In addition, it was analyzed that the effect of reducing muddy water in the Mandae district was insufficient due to the high ratio of leased farmers, lack of efforts to reduce turbid water in leased farmland, conversion to annual crops, and neglect of bare land. In the case of Gaa district, although the abatement facilities are concentrated in the upstream, muddy water was also found to be severe.

• 한국수자원학회논문집
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• 제47권10호
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• pp.973-983
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• 2014

본 연구는 밭경지 현장실험을 통해 다양한 초생대 초종을 적용하여 밭의 비점오염저감효과 분석 및 초생대에 적용 가능한 적합한 초종을 선정하고자 하였다. 경북 군위군에 위치한 면적 $1,500m^2$, 경사 5%의 밭경지를 선정하여 시험포를 조성하였으며, 시험포내에는 대조구 1개와 초생대 처리구 6개로 구성된 총 7개의 시험구를 조성하였다. 츄파, 피, 바랭이, 잔디, 톨페스큐, 켄터키블루그라스를 포함하는 6개의 초종을 선정하여 초생대 실험을 수행하였다. 현장실험 결과 대조구 대비 초생대의 유출저감효과는 6.1~77.8%였으며, 비점오염저감효과는 TS의 경우 15.6~90.3%, T-P의 경우 49.9~96.6%, T-N의 경우 6.7~91.1%를 나타내었다. 전체 오염인자 중에 초생대로 인해 전반적으로 높은 비점오염저감 효과를 나타낸 것은 TS, T-P, T-N, SS인 반면, BOD, TOC와 $NO_3^-$는 낮은 저감효과를 보였다. 비점오염저감 및 유지관리측면에서 가장 유리한 초생대 초종은 잔디로 평가되었다. 본 연구결과를 통해 우리나라 농촌지역 밭 비점오염저감을 위한 관리기법으로 초생대가 효과적으로 활용가능하리라 사료되며, 보다 장기적이고 다각적인 현장실험을 통해 초생대 현장적용을 위한 설계 지침서 개발이 요구된다.

• 한국습지학회지
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• 제11권3호
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• pp.9-19
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• 2009

본 연구에서는 계화간척농지로부터 발생 되는 비점원 오염물질 유출현황을 조사하였다. 간척 논면적은 2,988ha로 크게 1,181ha와 1,817ha 크기의 두개의 소유역으로 구성되어 있다. 두개의 소유역에 대해 각각 3번의 강우사상에 대해 조사가 이루어졌으며 강우량은 각각 66.0, 23.5, 23mm이었다. 간척농지에서 오염물질 유출 특성은 일반 내륙의 논에서와 다른 양상을 나타내었다. 일반적으로 우리나라 논에서는 발생되는 비점오염부하는 큰 반면에 연구대상 간척농지에서 발생되는 TSS, TN, TP의 비점오염 유출수준은 일반 임야지역 수준으로 나타났다. 다른 유역과 다르게 질소의 경우 용존성 유기질소가 주종을 이루고 있으며 인의 경우에는 용존성 인이 주종을 이루고 있었다.

• 식물병연구
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• 제24권2호
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• pp.99-112
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• 2018

Certain agrochemicals may be tuned for increased effectiveness when downsized to nanoparticles (NPs), where one dimension is less than 100 nm. The NPs may function as fertilizers, pesticides and products to improve plant health through seed priming, growth promotion, and induction of systemic tolerance to stress. Formulations will allow targeted applications with timed release, reducing waste and pollution when compared to treatments with bulk-size products. The NPs may be a single component, such as nano-ZnO as a fertilizer, or be composites of compatible materials, for example where N, P, and K plus micronutrients are available. The active materials could be loaded into porous carriers or tethered to base nanostructures. Coatings could include such natural products alginate, chitosan, zein, or silica. Certain NPs are taken up and transported in the plant's phloem and xylem so systemic effects are feasible. Timed and targeted release of the active product could be achieved in response to changes in pH or availability of ligands within the plant or the rhizosphere. Global research has revealed the many potentials offered by NP formulations to aid sustainability in agriculture. Current work will provide information needed by regulatory agencies to assess their safety in the agricultural setting.