• 한국농공학회:학술대회논문집
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• 한국농공학회 2002년도 학술발표회 발표논문집
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• pp.465-468
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• 2002

Land application is one of the desirable management practices for animal wastes. Majority of livestock farms adopt composting and land applications for the management of animal waste in this country. Meanwhile, there are only a few studies related with the effects of land application on pollutant loading. This study investigates the water quality characteristics in a rural watershed with intensive livestock farming. The results indicate that major constituents of water quality are substantially increased at the sites near livestock farms and compost incorporated fields during the rainfall-runoff periods. There are no significant differences of water quality parameters among the sampling sites during no rain periods.

• 상하수도학회지
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• 제31권3호
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• pp.219-228
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• 2017

Burial sites are constructed for the purpose of controlling air-born livestock diseases such as avian influenza and foot-and-mouth outbreak. As most of the burial sites are located in the agricultural land use, public concerns are mounting about soil and groundwater contamination. During precipitation events, contaminated baseflows are released from the burial sites into surface waters. Baseflow are therefore required to be managed properly, by monitoring and even by remediation means. We propose each burial sites should be regarded as a point source possibly degrade groundwater, thus be managed in watershed scale for the purpose of surface water quality conservation.

• 한국농공학회논문집
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• 제59권3호
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• pp.83-96
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• 2017

This study presented a surface water quality modeling framework considering the spatial resolution of pollutant load estimation to better represent stream water quality characteristics in the Saemangeum watershed which has been focused on keeping its water resources sustainable after the Saemangeum embankment construction. The watershed delineated into 804 sub-watersheds in total based on the administrative districts, which were units for pollutant load estimation and counted as 739 in the watershed, Digital Elevation Model (DEM), and agricultural structures such as drainage canal. The established model consists of 7 Mangyung (MG) sub-models, 7 Dongjin (DJ) sub-models, and 3 Reclaimed sub-models, and the sub-models were simulated in a sequence of upstream to downstream based on its connectivity. The hydrologic calibration and validation of the model were conducted from 14 flow stations for the period of 2009 and 2013 using an automatic calibration scheme. The model performance to the hydrologic stations for calibration and validation showed that the Nash-Sutcliffe coefficient (NSE) ranged from 0.66 to 0.97, PBIAS were -31.0~16.5 %, and $R^2$ were from 0.75 to 0.98, respectively in a monthly time step and therefore, the model showed its hydrological applicability to the watershed. The water quality calibration and validation were conducted based on the 29 stations with the water quality constituents of DO, BOD, TN, and TP during the same period with the flow. The water quality model were manually calibrated, and generally showed an applicability by resulting reasonable variability and seasonality, although some exceptional simulation results were identified in some upstream stations under low-flow conditions. The spatial subdivision in the model framework were compared with previous studies to assess the consideration of administrative boundaries for watershed delineation, and this study outperformed in flow, but showed a similar level of model performance in water quality. The framework presented here can be applicable in a regional scale watershed as well as in a need of fine-resolution simulation.

• 지질공학
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• 제10권3호
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• pp.263-272
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• 2000

본 연구의 목적은 GlS와 수문모형(HIS)을 이용하여 오원천 유역에서 강우와 유출량의 관계를 산정하기 위함이다. 본 연구에서 유역인자와 지형인자는 GIS를 이용하여 DEM으로부터 추출하였으며, 그 외의 자료들은 1:50,000 지형도를 이용하여 추출하였다. 수문모형에서 이용되는 변수인 유역면적(A), 유로연장, SCS CN 값 등은 대상유역에서 GIS을 이용하여 추출하였으며, 추출된 변수들을 수문모형에 적용하여 강우-유출량의 관계를 모의하는데 이용하였다. 그리고 계산된 유출량과 관측 유량을 이용하여 매개변수를 최적화하였다. 그리고 모의된 매개변수를 토대로 수문모형에 적용하여 강우-유출량 관계를 확정하였다. 그 결과 수문모형은 강우-유출량의 관계를 성공적으로 모의하였다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회 논문집
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• pp.492-496
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• 2005

하천은 정치적, 행정적, 사회적 구분을 자유자재로 넘나들고 물과 토지는 강한 연관성을 가지고 있다. 물과 하천의 이러한 특성들은 수자원을 효율적으로 관리하는데 큰 제약요소로 간주되어 왔다. 따라서 수자원을 유역이라는 한정된 범위 내에서 모든 인간활동과 자연현상을 통합적으로 고려한다는 개념은 바람직한 관리방안으로 알려지고 있다. 유역관리는 이러한 관점에서 물을 경제적이고 공평하게 관리하고 분배하여 수자원에 대한 장기적이고 지속가능한 해결방안을 마련하는 것이다. 본 연구는 유역관리에 대한 한국과 미국의 차이점을 파악하기 위하여 크게 세 가지 부분으로 이루어져 있다. 첫 번째 부분은 한국에서 1960년대 이후 시작된 유역관리가 1990년대에 수질관리 차원의 대유역관리로 진행되는 과정을 고찰하였다. 두 번째에는 미국에서 대유역관리가 실종되고 소유역관리가 확산되는 과정을 밝혔다. 마지막으로 유역관리에 대한 한국과 미국의 전개과정을 비교검토하고 그 차이점을 평가하였다. 미국에서는 대유역관리에 대한 관심이 쇠퇴한 반면에 수문학적 지역으로서의 소유역이 주요 관심대상으로 떠오르고 있다. 이에 반하여 우리나라에서는 현재 정치적 차원의 물관리체제개편과 사회적 차원의 강살리기운동이 동시에 전개되고 있다. 따라서 우리나라가 당면한 유역관리의 과제는 미국보다도 더욱 복합적이다.

• 한국수자원학회논문집
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• 제36권6호
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• pp.1059-1068
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• 2003

본 연구는 아산만으로 유입되는 유사량을 추정하기 위하여 Landsat-5 TM 위성영상과 NGIS 수치자료를 이용하여 대상유역의 기본도와 USLE 주제도를 구축하고, 범용토양유실공식(USLE)을 이용하여 아산만 유역의 토양유실량을 추정하였다. 유사운송비와 포착률을 이용하여 아산만으로 유입되는 유사량을 추정하였으며, 이를 농업기반공사의 배수갑문 관리자료와 환경부의 담수호 부유물 측정자료로부터 구한 실측 유사량과 비교하였다. USLE와 유사운송비, 포착률을 이용해 추정된 값과 실측 유입유사량을 비교한 결과, 아산호의 경우 연평균 추정치는 5,665tonnes/yr, 실측치는 12,937tonnes/yr, 삽교호의 경우 추정치는 6,765tonnes/yr, 실측치는 12,395 tonnes/yr 으로 나타났다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2008년도 학술발표회 논문집
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• pp.1295-1299
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• 2008

Soil erosion is a natural process and has been occurring in most areas in the watershed. However, accelerated soil erosion rates have been causing numerous environmental impacts in recent years. To reduce soil erosion and sediment inflow into the water bodies, site-specific soil erosion best management practices (BMPs) need to be established and implemented. The most commonly used soil erosion model is the Universal Soil Loss Equation (USLE), which have been used in many countries over 30 years. The Sediment Assessment Tool for Effective Erosion Control (SATEEC) ArcView GIS system has been developed and enhanced to estimate the soil erosion and sediment yield from the watershed using the USLE input data. In the last decade, the Soil and Water Assessment Tool (SWAT) model also has been widely used to estimate soil erosion and sediment yield at a watershed scale. The SATEEC system estimates the LS factor using the equation suggested by Moore and Burch, while the SWAT model estimates the LS factor based on the relationship between sub watershed average slope and slope length. Thus the SATEEC and SWAT estimated soil erosion values were compared in this study. The differences in LS factor estimation methods in the SATEEC and SWAT caused significant difference in estimated soil erosion. In this study, the difference was -51.9%(default threshold)$\sim$-54.5%(min. threshold) between SATEEC and non-patched SWAT, and -7.8%(default threshold)$\sim$+3.8%(min. threshold) between SATEEC and patched SWAT estimated soil erosion.

• 한국농공학회논문집
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• 제50권1호
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• pp.3-12
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• 2008

Soil erosion is a natural process and has been occurring in most areas in the watershed. However, accelerated soil erosion rates have been causing numerous environmental impacts in recent years. To reduce soil erosion and sediment inflow into the water bodies, site-specific soil erosion best management practices(BMPs) need to be established and implemented. The most commonly used soil erosion model is the Universal Soil Loss Equation(USLE), which have been used in many countries over 30 years. The Sediment Assessment Tool for Effective Erosion Control(SATEEC) ArcView GIS system has been developed and enhanced to estimate the soil erosion and sediment yield trom the watershed using the USLE input data. In the last decade, the Soil and Water Assessment Tool(SWAT) model also has been widely used to estimate soil erosion and sediment yield at a watershed scale. The SATEEC system estimates the LS factor using the equation suggested by Moore and Burch, while the SWAT model estimates the LS factor based on the relationship between sub watershed average slope and slope length. Thus the SATEEC and SWAT estimated soil erosion values were compared in this study. The differences in LS factor estimation methods in the SATEEC and SWAT caused significant difference in estimated soil erosion. In this study, the difference was -51.9%(default threshold)${\sim}-54.5%$(min. threshold) between SATEEC and non-patched SWAT, and -7.8%(default threshold)${\sim}+3.8%$(min. threshold) between SATEEC and patched SWAT estimated soil erosion.

• 한국환경농학회지
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• 제28권2호
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• pp.113-124
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• 2009

Severe sediment-laden problem has been the hot issue in Korea. It was assumed that agricultural activities and landslides were the primary causes of these problems in watersheds. The USLE-based systems have been widely used in soil erosion studies. However the GIS-based USLE modeling system has limitation in USLE L factors. In this study, the SATEEC L module was developed to reflect the slope length segmentations in the fields. The SATEEC L module was applied to the study watershed to analyze the effects of using the SATEEC L module on estimated sediment. As shown in the comparisons between SATEEC estimated sediment with SWAT values, the SATEEC GA-SDR module derives the SDR with reasonably acceptable accuracies. However, it is worthy to note that the soil erosion using the SATEEC L module for the study watershed was lower than that without using the SATEEC L module by 25%, although the SATEEC estimated sediment values with and without using L module match the SWAT sediment values with similar accuracies. This is because the SATEEC GA-SDR module estimates lower SDR in case of greater soil erosion estimation without the L module and greater SDR in case of lower soil erosion estimation with the L module. This indicates that the SATEEC input parameters, especially L factor, need to be prepared with care for accurate estimation of SDR at a watershed scale and for accurate evaluation of BMPs in the watershed.

• 환경영향평가
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• 제9권3호
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• pp.163-176
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• 2000

The purpose of this study is to analyze the pollutant loads and its distribution, and to suggest the management of nonpoint sources in Daechong Reservoir. The loads from point and nonpoint sources such as population, industry, livestock and land use were calculated per stream or river with topography(1:25,000) of the watershed of Daechong Reservoir. The generating pollutant loads were obtained through multiplication of pollutant sources by generating pollutant quantity per unit pollutant source. The effluent point sources loads is defined as loads from wastewater treatment facilities such as domestic, industrial and livestock wastewater treatment facilities, which were calculated through multiplication of effluent flowrates by water quality constituents concentration. Untreated point sources loads were estimated to be 35 % of total point sources loads. The effluent nonpoint sources pollutant loads were obtained through the multiplication of generating nonpoint sources loads by effluent ratios based on previous studies. The effluent nonpoint sources loads have the ratio of 26.2% of total BOD effluent loadings, 20.1% of total T-N effluent loadings, and 10.5% of total T-P effluent loadings. For the reduction of nonpoint sources loads in Daechong Reservoir, silviculture, artificial wet land, and grassed waterways could be applied. And untreated livestock waste scattered can result in nonpoint loadings, so required the livestock wastes treatment facilities and purifying facilities together with the management of shed, pasture, livestock waste storage site and composting site. Finally, remote sensing and GIS should be applied to the identification of distribution of water quality, watershed, the location and scale of nonpoint sources, effluent process during rainfall, for more detailed analysis of nonpoint sources.