• 한국농공학회논문집
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• 제60권1호
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• pp.59-65
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• 2018

The object of this paper was to analyze combined load acting on agricultural reservoir. This study was carried out to 3-D numerical modeling for displacement characteristic and seismic acceleration characteristic. The results of study were analyzed and summarized as follow. It was found that the displacement caused by combined load acting on railway and agricultural reservoir did not reflect the effect of load and the seismic wave consistently. The ground accelerations that occur in railway and dam were amplified because 3-D numerical analysis program interprets ground as an elastic body. Actual ground shows characteristics of elasticity and plasticity, so measured values will show different tendency. As a result of analyzing displacement characteristics, it is considered to be related to stiffness. The Ofunato seismic wave, the displacement (77.1 mm) of the body satisfied the allowable displacement (220 mm), but The Hachinohe seismic wave (282.8 mm) did not. It is considered that displacement caused by combined load is affected not only by acceleration but also by characteristics of materials.

• 농촌계획
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• 제23권2호
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• pp.87-96
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• 2017

This study is a basic research with the aim of developing the method of judging the leakage zone by grasping the habitat characteristic of agricultural reservoir slope in inhabiting characteristics appear differently according to natural inhabiting environment. To this end, this study is intending to investigate slope vegetation using a quadrat technique at Sinheung reservoir located at Gwangsi-myeon, Yesan-gun, Chungnam, and to perform the analysis of importance value using relative frequency and relative coverage, etc. Also, this study intended to present the necessity of having to consider the eco-system of the relevant region in time of a reservoir slope afforestation for the time to come by suggesting that the reservoir slope vegetation after a stable period becomes similar to the regional vegetation by comparing this study result with the existing research which carried out the analysis of importance value of forest vegetation for Yesan Region. The reservoir slope vegetation is similar to the indicator species which appear in the regional forest vegetation, so there was a need to select afforestation species in the light of this in time of slope afforestation. As a result of the analysis of the importance value, this study grasped that there was an emergence characteristic similar to the vegetation at a birthplace of a forest fires because growth and development of forest trees, and perennial plants were restricted by annually implemented brush-cutting work, etc.; however, indigo plant and bush clover, etc. were found to show the characteristic differing from this. Consequently, this study was able to confirm that there is the necessity of having to create the Importance Value Table suited for reservoir slopes by region through a lot more data construction in the near future.

• 대한토목학회논문집
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• 제33권4호
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• pp.1389-1400
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• 2013

본 연구에서는 농업용 둑높임저수지의 다중용수공급능력(관개 및 하천유지용수) 평가에 따른 이수운영기준곡선을 개발하였다. 20개 둑높이기 사업지구를 대상으로 특성분석에 따른 4개(웅양, 궁촌, 용암, 운암)의 대표 저수지를 선정하고, 이수운영모형을 이용한 물수지분석을 통해 하천유지용수 공급 가능량을 산정하였다. 이수운영기준은 관개기와 비관개기에 대해 방류제한수위(사업전 만수위)에서 상시만수위까지의 저수위구간을 하천유지용수공급 가능 수위로 설정하고 신뢰도, 회복도 및 취약도 지수를 이용하여 각 둑높임저수지 특성별 물공급 능력을 평가하였다. 이수운영기준 적용에 따른 둑높임저수지의 이수운영기준곡선은 과거 이수운영모의결과로부터 일별 저수위를 백분위(Percentile Rank)로 표현하였다. 각 분위별 저수위 구간을 3개의 완충구간(Buffer)으로 나누어 갈수년(5~25%), 평수년(25~75%) 및 풍수년(75~95%)에 해당하는 저수지 운영이 가능하도록 하였다.

• 한국농공학회논문집
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• 제58권6호
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• pp.9-21
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• 2016

Agricultural reservoirs in Korea have been recognized as an emerging resource for recreational and cultural activities for residents. However, most of the reservoirs are eutrophic and showing high level of contamination with nuisance algal bloom and offensive odor during the summer. For better management and restoration of the reservoirs' water quality, scientific modeling approaches could be used to diagnose the problems and evaluate the efficacy of alternative control measures. The objectives of this study were to validate the performance of a three-dimensional (3D) hydrodynamic and water quality model (Environmental Fluid Dynamics Code, EFDC) for a eutrophic agricultural reservoir and assess the effect of bypassing of the effluent from a wastewater treatment plant on the reservoir water quality. The 3D model successfully simulated the temporal variations of water temperature, DO, TOC, nitrogen and phosphorus species and Chl-a observed in 2014 and also captured their spatial heterogeneity in the reservoir. The simulation results indicated that the point source bypassing may reduce the T-N and T-P concentrations of the reservoir by 6.6 ~ 8.2 %, and 1.7 ~ 16.8 %, respectively. The bypassing, however, showed a marginal effect on the control of TOC due to the increased algal biomass associated with the increased water retention time after bypassing as well as the lower TOC level of the effluent compared to the ambient reservoir water.

• 한국콘텐츠학회논문지
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• 제11권9호
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• pp.246-253
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• 2011

농업용수를 확보하기 위하여 조성한 호소에 장기간 물을 담수함에 따라 수질오염으로 이용가치 저하와 하류 하천이 건천화 되어 하천의 기능을 상실하는 등 유역내 잘못된 물 관리체계로 여러 가지 문제점이 발생하고 있다. 충남 대전지역을 중심으로 농업용 호소의 운영현황을 조사한 결과 대부분 호소수의 체류시간은 8개월 이상을 유지하여 그 기간 동안 하류하천의 건천화가 나타났고, 호소수의 수질은 생활계 및 축산계 오염물질의 유입과 강수량에 따른 물 순환특성과 상당히 밀접한 것으로 분석되었다. 따라서 호소 유역내수질오염물질 저감과 함께 하류하천이 건천화가 되지 않도록 담수량과 담수시기를 조절하고, 호소수 체류 시간은 가급적 짧게 유지하는 등 유역내 물 순환체계를 개선할 필요가 있다.

• 한국수자원학회논문집
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• 제51권4호
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• pp.371-381
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• 2018

국내 농업용 저수지 댐 시설물은 노후화 및 기후변화로 인한 여름철 강우량 증가로 인해 수자원관리에 대한 어려움뿐만 아니라 댐 월류에 따른 피해위험이 높을 것으로 전망된다. 따라서 본 연구에서는 기후변화를 고려한 농업용 저수지 수문학적 안전성을 평가하기 위해 농업용 저수지 1종 댐 시설물을 대상유역으로 선정하였으며, 유역별 확률강우량, 기존에 제시된 Present PMP, 기상청 기후변화시나리오에 따른 Future PMP를 산정하였다. 또한, 기후변화에 따라 증가하는 강우량을 정량적으로 분석하고, 홍수량산정 및 저수지홍수추적을 실시하여 강우시나리오에 따른 농업용 저수지의 여유고를 분석하였다. 기후변화를 고려한 Future PMP를 이용하여 농업용 저수지 댐 시설물의 수문학적 안전성을 평가한 결과, 고삼, 금광, 미호, 청천저수지는 설계홍수위 이상의 최고수위가 발생함에 따라 월류위험에 취약할 것으로 분석되었다.

• 한국농공학회논문집
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• 제60권1호
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• pp.1-10
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• 2018

This study analyzed pore water pressure, seepage and leakage quantity, height of seepage and critical hydraulic gradient in order to suggest the seepage characteristics of agricultural reservoir embankment considering filter interval. The seepage characteristics of a deteriorated reservoir embankments were conducted according to the horizontal filter intervals range using three- dimensional finite element analysis. The wider the horizontal filter interval, the higher the pore water pressure increased, and the pore water pressure ratio in the center of the core has a greater effect than the base part. The seepage and leakage quantity appeared largely in the two-dimensional analysis conditions (case 1), where the filter was constructed totally in the longitudinal direction of the embankment, the wider the horizontal filter interval was gradually reduced. The reasonable filter intervals to yield efficient seepage characteristics were within 30 m for the pore water pressure of the core and the height of the seepage line. The stability of the filter installation was able to evaluate the stability of the piping by the critical hydraulic gradient method. The deteriorated reservoir with no filters or decreased functionality can significantly reduce the possibility of piping by simply installing a filter on the downstream slope. In the future, the deteriorated reservoir embankment should be checked for the reservoir remodeling because the core and filter functions have been lost or decreased significantly. In the case of a new installation, the seepage characteristic behavior due to the core and filter changes should be applied to the field after obtaining a reasonable horizontal filter interval that satisfies the safety factor by a three-dimensional analysis.

• 한국농공학회논문집
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• 제60권6호
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• pp.1-12
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• 2018

The objectives of this study were to develop a system linking hydrologic and water quality models considering the mechanisms of agricultural reservoir and paddy cultivation and to evaluate whether the developed system simulates hydrologic and water quality processes better than a hydrologic model that do not consider the mechanisms. The system consisted of Hydrological Simulation Program-Fortran (HSPF) as a watershed model, Module-based hydrologic Analysis System for Agricultural watersheds (MASA) as reservoir water balance model, and Chemical, Runoff and Erosion from Agricultural Management System-Paddy (CREAMS-PADDY) as a hydrologic and water quality model for paddy fields. This study carried out on the Seolseong-Cheon watershed in Icheon, and the water level and water quality had been monitored for two years at the outlet of the watershed. According to the results of this study, the performance of the simulation using HSPF-MASA-CREAMS-PADDY system was better than others, but they did not show a statistically significant difference. This seemed to be due to the uncertainty of the farming data and the water quality data of the reservoir. Therefore, if accurate input data for the system is obtained, HSPF-MASA-CREAMS-PADDY system could be used to model an agricultural watershed to obtain more realistic results. The results of this study could be utilized to the modeling of agricultural watersheds in Korea where paddy rice cultivation is dominant.

• 한국농공학회지
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• 제40권2호
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• pp.69-80
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• 1998

The optimal reservoir storage capacity is needed to be determined at the stage of reservoir planning. The reservoir storage capacity should be based on water balance between demand and supply, and meet the water deficity during the growing season. However, the optimal reservoir storage capacity should be determined considering benefit-cost analysis for the project. In this study, Two models are developed. The one is the RSOM(Reservoir Storage Optimization Model), that is consisted by three submodels, MROPER (Modified Reservoir OPERation model), RESICO(REservoir SIze and the construction COst computation) model. And the other is the BECA(BEnefit-Cost Anaysis) model. For model application, three districts, Chungha, Ipsil and Edong were selected. The relative difference of B/C ratio between project planning data and estimation by RSOM is 17.9, 15.0 and 7.3% respectively, which may be applicable for water resources development feasibility planning.

• 농업과학연구
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• 제38권3호
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• pp.513-524
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• 2011

To evaluate the applicability of inflow runoff model to reservoir operation in Korea, DAWAST model and TPHM model which are conceptual lumped daily runoff model and were developed in Korea, were selected and applied to simulate inflows to Daecheong multipurpose dam with watershed area of 4,134 $km^2$, and water storages in Geryong reservoir with watershed area of 15.1 $km^2$ and total water storage of 3.4 M $m^3$. Evaluating inflows on an yearly, monthly, ten-day, and daily basis, inflows by DAWAST model showed balanced scatters around equal value line. But inflow by TPHM model showed high in high flows. Annual mean water balance by DAWAST model was rainfall of 1,159.9 mm, evapotranspiration of 622.1 mm, and inflow of 644.6 mm, from which rainfall was 104.8 mm less than sum of evapotranspiration and inflow, and showed unbalanced result. Water balance by TPHM model showed satisfactory result. Reservoir water storages were shown to simulate on a considerable level from applying DAWAST and TPHM models to simulate inflows to Geryong reservoir. But it was concluded to be needed to improve DAWAST and TPHM model together from imbalance of water balance and low estimation in high flow.