• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.443-443
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• 2021

국내 하천, 호소에 유입되는 오염물질 중 30% 이상이 농업 활동 등으로부터 기인한다. 정부 부처는 '04년부터 농업 비점오염원 저감 대책을 수립·시행하고 있으나 농촌 인구 고령화, 열악한 재정환경, 관행화·고착화 된 농법 등으로 인해 주민참여 및 대책 적용의 한계가 있었다. 금호강 상류 보현산댐 유역은 대부분 임야로 고현천 등 상류 하천변에 사과원이 밀집되어 있다. 또한, 유역면적이 32.16km²로 좁고, 유로 연장 5km 이내로 짧으며 하천 경사가 급해 강우시 토양 유실량이 많고 유출속도가 빠르다. 이러한 유역 특성상 상류 사과원은 '16년 보현산댐 담수 이후 매년 반복적으로 발생하는 녹조 등 수질 문제를 초래하는 주요 비점오염원으로 지역사회 이슈가 되었다. 이에 따라 K-water는 낙동강수계관리위원회 환경기초조사사업의 일환으로 지역주민들과 논의를 통하여 댐 상류 사과원에 친환경농법(심층시비)를 적용하고 수질 개선 효과를 분석하였다. 심층시비는 과수 주변 토양 천공 후 퇴비를 시비하는 친환경농법으로 표층시비에 비해 초기 강우유출 오염물질량을 저감하고 퇴비 사용량도 줄일 수 있다. 금번 연구에서 실제 운영 중인 농지('19년 24천평, '20년 27천평)을 대상으로 심층시비를 시범적용한 결과, 퇴비 사용량은 표층시비의 50% 수준으로 감소하였고 과수 생육 및 품질에는 큰 영향이 없는 것으로 나타났다. 강우 시 유출농도는 표층시비 대비 TOC 5.0~41.3%, T-P 4.0~57.3% 감소했다. HSPF 유역 모델링 분석 결과, 전체 과수원 중 70% 농지에 심층시비를 적용한 경우, 하절기 유역 T-P 유입부하량이 5.0~6.8%(소유역 최대 28.2%) 감소하는 것으로 예측되었다. 본 연구결과를 바탕으로 심층시비를 확대 적용하고 유역 수질관리에 기여하고자 한다.

• Magazine of the Korean Society of Agricultural Engineers
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• v.39 no.1
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• pp.41-47
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• 1997

A geographical resource analysis support system (GRASS) was incorporated to an input and output processor for the agricultural nonpoint source pollution (AGNPS) model. The resulting interface system, GIS-AGNPS was a user-friendly, menu-driven system. GIS-AGNPS was developed to automatically process the input and output data from GIS-based data using GRASS and Motif routines. GIS-AGNPS was consisted of GISAGIN which was an input processor for the AGNPS model, GISAGOUT a output processor for the AGNPS and management submodel. The system defines an input data set for AGNPS from attributes of basic and thematic maps. It also provides with editing modes so that users can adjust and detail the values for selected input parameters, if needed. The post-processor at the system displays graphically the outputs from AGNPS, which may he used to identify areas significantly contributing nonpoint source pollution loads.

• Korean Journal of Agricultural Science
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• v.26 no.2
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• pp.61-69
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• 1999

The water quality of river has been deteriorated mainly by both point source pollution and nonpoint source pollution from the watershed. Techniques to cut point source pollutants down to the level required have been developed. But, techniques of best management practices to catch the nonpoint source pollutions and to control the routine of pollutants were not successively developed. The quality of closed water system such as reservoir, lake and farm pond is irresistable to being polluted mainly by nonpoint source pollutions. In this study, the population, land use, runoff coefficient, amount of rainfall, and runoff discharge in the watershed were surveyed to investigate the characteristics of water quality such as BOD, COD, SS, T-N, and T-P. After studying the changes of water quality in the viewpoint of land use such as paddy land, residential area, upland, forest and meadow, load factors of nonpoint source pollutant were calculated in Bangdong reservoir watershed. Residential area was more severe than other land use as far as BOD, COD and SS concerned. T-N and T-P released from the paddy and upland were higher than other land use. The 45.9% of total load of nonpoint source pollution was occured during the rainy season.

• Magazine of the Korean Society of Agricultural Engineers
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• v.39 no.2
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• pp.53-61
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• 1997

The interface system, GIS-AGNPS was to be validated with field data from six tested small watersheds ranging from 0.7 to 4.7$km^2$ in size which have steep topography and complex landuses. The model validation involved the calibration of input parameters and component modifications, in efforts to develop a model applicable to general uses for identifying and controlling nonpoint source pollution loads from agricultural watersheds. The simulated direct runoff from AGNPS was in good agreement with the field data for the averaged antecedent moisture conditions or AMC- II. The results differed, however, from the observed for AMC- I or III. A simple empirical relationship was proposed to estimate the curve number for AMC- I or m from AMC- II, which was found to result in simulated runoff close to the observed. The peak runoff relationship at AGNPS was also modified to reflect the watershed conditions and tested satisfactorily with the field data. The simulated sediment yields from the watersheds were fair as compared to the observed. Nutrient loads simulated from the model were different from the observed data. It appeared that the model was incapable of adequate depicting nutrient transport processes at paddy field and other landuses of the tested watersheds. Some modifications may be needed for the accurate representing the processes at paddy field.

• Magazine of the Korean Society of Agricultural Engineers
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• v.38 no.4
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• pp.46-52
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• 1996

비점원오염은 여러가지가 있는데 그 중에서 농약에 의한 오염은 통제나 관리가 어려워서 효과적인 관리방법으로 IPM개념의 도입이 가장 적합하다고 판단되며, 미국에서 실제 적용 해본 결과 우리나라에서도 지형적 특성이나 농업형태에 따라 적용할 수 있는 가능성이 있으며 이 부분에 관한 연구가 필요하다. 농약이란 제거 또는 억제하고자 하는 생명체에 위해를 가하는 화학약품이기 때문에 다른 생명체에도 정도의 차이는 있으나 위해를 끼칠 수 있다. 이러한 농약성분들은 일정한 기간 약효를 나타내는 것이 특징인데,제품에 따라서는 자연분해가 느려서 생태계에 오랫동안 잔류하는데, 이 경우에 잔류농약이 사용목적외에 다른 생태계로 이동하여 피해를 입히고 인체의 건강에도 악영향을 미치게 된다. 이처럼 생태계뿐만 아니라 인체의 건강에 직접적으로 피해를 줄 수 있는 농약은 사용에 신중을 기하고, 되도록 사용량을 감소시켜야 하며, 환경친화형인 농약제품의 개발과 안전하고 손실이 적으며 효과적인 농약투입방법의 사용이 요구된다.

• Journal of Korea Water Resources Association
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• v.32 no.4
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• pp.501-510
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• 1999

Stream and groundwater qualities of small agricultural watershed in Kangwon Probince, Korea were monitored 1 to 2 years, and the relationships between stream and groundwater qualities and seasonal water quality changes analyzed. Flooded paddy fields influenced groundwater level and quality during rice culture. The differences between groundwater levels during rice culture and non-culture spans were between 0.8 and 2.91 m. Seasonal changes of total nitrogen and nitrate nitrogen concentrations of stream and groundwater were very similar and groundwater quality was thought to have a profound impact on stream quality of the research watersheds. Suspended solids and BOD maintained the first degree stream water quality throughout the monitoring period except for a few and short flooding spans. The concentrations of total phosphorus and total bacteria of both waters showed wide variations and any seasonal trends were not observed. Long-term monitoring studies on small rural watersheds were recommended to understand the pattern of both stream and groundwater quality changes with respect to land use, season and cultural practice, and to apply the results to develop effective water quality management policies for large river and domestic water supply systems.

• Journal of agriculture & life science
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• v.45 no.5
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• pp.97-103
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• 2011

The purpose of this study was to analyze the pollutant reduction effect for non-irrigated crop land by nonpoint source pollution control. For a field scale monitoring, 6 plots (5m width and 22m length) and 3 sediment traps were installed. At the outlet of each plot, the stage gauges were installed for runoff monitoring. For a rainfall monitoring, tipping bucket rain gage was installed within the experiment site. Through the artificial irrigation, runoff from the plots were monitored. The SS, TOC, T-N, T-P, COD, NTU of sampled water were analyzed by standard methods. The SS, TOC, T-N, T-P, COD, NTU concentration of initial runoff were 15.00, 1.54, 5.27, 0.07, 4.72, 0.45mg/L, respectively. Four hours later than the initial runoff, the concentration was changed to 1.00, 0.94, 4.06, 0.01, 0.60, 0.33 mg/L, respectively. As a result of artificial irrigation, three out of four sediment traps were filled with runoff water from the experimental plots. One sediment trap was not filled with runoff water because the artificial irrigation was not supplied for two experimental plots. The stage of sediment traps were gradually lowered. However, the water quality didn't showed a decrease trend as the stage went down because the suspended solid was not equally collected during the water sampling.

• Journal of Wetlands Research
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• v.25 no.2
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• pp.99-110
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• 2023

Non-point source (NP) pollutants in an agricultural landuse are discharged from a large area compared to those in other land uses, and thus effective source control measures are needed. To develop appropriate control measures, it is necessary to quantify discharge load of each source and evaluate the degree of water quality improvement by implementing different options of the control measures. This study used Hydrological Simulation Program-FORTRAN (HSPF) to quantify pollutant discharge loads from different sources and effects of different control measures on water quality improvements, thereby supporting decision making in developing appropirate pollutant control strategies. The study area is the Gyeseong river watershed in Changnyeong county, Gyeongsangnam-do, with agricultural areas occupying the largest proportion (26.13%) of the total area except for the forest area. The main pollutant sources include chemical and liquid fertilizers for agricultural activities, and manure produced from small scale livestock facilities and applied to agriculture lands or stacked near the facilities. Source loads of chemical fertilizers, liquid fertilizers and livestock manure of small scale livestock facilities, and point sources such as municipal wastewater treatment plants (WWTPs), community WWTPs, private sewage treament plants were considered in the HSPF model setup. Especially, NITR and PHOS modules were used to simulate detailed fate and transport processes including vegitation uptake, nutrient deposition, adsorption/desorption, and loss by deep percolation. The HSPF model was calibrated and validated based on the observed data from 2015 to 2020 at the outlet of the watershed. The calibrated model showed reasonably good performance in simulating the flow and water quality. Five Pollutants control scenarios were established from three sectors: agriculture pollution management (drainge outlet control, and replacement of controlled release fertilizers), livestock pollution management (liquid fertilizer reduction, and 'manure management of small scale livestock facilities) and private STP management. Each pollutant control measure was further divided into short-term, mid-term, and long-term scenarios based on the potential achievement period. The simulation results showed that the most effective control measure is the replacement of controlled release fertilizers followed by the drainge outlet control and the manure management of small scale livestock facilities. Furthermore, the simulation showed that application of all the control measures in the entire watershed can decrease the annual TN and TP loads at the outlet by 40.6% and 41.1%, respectively, and the annual average concentrations of TN and TP at the outlet by 35.1% and 29.2%, respectively. This study supports decision makers in priotizing different pollutant control measures based on their predicted performance on the water quality improvements in an agriculturally dominated watershed.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.103-103
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• 2012

본 연구에서는 시험포장($1276.6m^2$)에서의 지표피복 BMPs (Best Management Practices) 시나리오를 적용하여 얻은 평균 유출저감율을 HSPF 모델에 적용하여 유역차원에서의 비점원오염 저감효과를 평가하고자 한다. 본 연구에서는 별미천 유역($1.21km^2$)을 대상으로 모형의 적용을 위한 입력자료로 기상자료와 지형자료를 구축하였으며 기상자료로 수원, 양평, 이천 기상관측소 자료를 구축하였으며, 지형자료로 격자크기 2m의 DEM (Digital Elevation Model)과 토지이용도는 2006년 5월 1일 QuickBird 영상을 제공받아 기존 환경부, 건교부, USGS의 토지피복분류체계 및 현장조사를 통하여 QuickBird 영상으로부터 추출 가능한 정밀농업정보에 대한 항목을 결정하였으며, 정사보정된 QuickBird 영상을 스크린 디지타이징 기법(On-Screen Digitizing Method)을 이용하여 총 21개 토지이용항목의 정밀토지이용도를 구축하였다. 실제모니터링으로 측정된 자료를 바탕으로 수위-유량곡선 산정 및 오염부하곡선을 선정, 2011년 6월 8일부터 10월 31일 분석기간으로 HSPF 모델링을 실시하였으며 모의결과 월별 통계에 따른 적용성 분석으로 RMSE (Root Mean Square Error) 는 1.15 ~ 1.76(mm/day), $R^2$는 0.62 ~ 0.78, Nash-Sutcliffe model efficiency (NSE)는 0.62 ~ 0.76로 모의치는 실측치와 유의성이 있는 것으로 분석되었다. 또한, Sediment, T-N, T-P의 $R^2$는 각각 0.72, 0.62, 0.63으로 상관성을 보이는 것으로 분석되었다. 시험포장으로부터 얻어진 event별 볏짚을 이용한 지표피복시나리오적용 후 밭에서의 평균 유출 약 10 % 유출율 감소 조건과 실제 평균 비점원오염 저감효과 89.7 % ~ 99.4 %의 결과로부터 지표피복효과의 침투효과를 HSPF 모델로 적용하기 위해 침투량(INFILT)를 조절하여 평균유출 약 10 %가 감소되는 16.0 mm/hr 값을 선정하였다. 그 결과, Sediment. T-N, T-P의 평균 저감율은 각각 87.2 %, 28.5 %, 85.1 %로 나타났으며 이는 시험포장에서의 실제 평균 비점오염 저감효과 89.7 % ~ 99.4 %에 근접함을 알 수 있었다. 이 결과로부터 침투량 조절에 따른 지표피복(침투짚단)효과는 Sediment, T-P에서 저감효율이 80 % 이상으로 높았지만 T-N은 약 30 %로 낮은 저감율을 보임으로써 저감효과가 크지 않음을 나타냈다.

• Magazine of the Korean Society of Agricultural Engineers
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• v.40 no.4
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• pp.85-93
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• 1998

In the 2nd year study of a 5 year project to evaluate the soil quality and develop the best management practices for mountaineous soils, 11 runoff plots were treated and monitored with respect to physical property of the soil, runoff and sediment discharge, and the following results were obtained. 1. Bulk density and porosity did not show any siginificant difference between experimental treatments. 2. Runoff was basically dependent on the soil's physical property and tillage. Up-and-down plots showed the highest runoff while contour plots the lowest runoff. 3. Sediment yield in the mountaineous soils was directly related to tillage and residue cover. Residue covered plots showed the lowest sediment yield and up-and-down plots the highest sediment yield. And it is recommended that the best management practices using till_age and residue cover for the mountaineous soils must be developed to protect soil quality and maintain agricultural productivity.