• 한국관개배수논문집
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• 제17권2호
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• pp.57-70
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• 2010

This study was performed to analyze the affect of water supply capacity followed by allocating flood control volume in heightening reservoir, of which Baekgog reservoir was selected as a case study in here. Baekgog reservoir is located in Jincheon county, Chungbuk province, of which full water level will be heightened from EL. 100. 1m to EL. 102.1m, and total storage from 21.75M $m^3$ to 26.67M $m^3$. Flood inflow with 200year frequency was estimated to 997 $m^3$/s in peak flow and 22.54M $m^3$ in total volume. Reservoir flood routing was conducted to determine flood limited water levels, which was determined to have scenarios such as EL 97-98-99m in periods of 6.21.-7.20., 7.21.-8.20., and 8.21.-9.20., respectively, EL 97-97-97m, EL 98-98-98m in present reservoir, and EL 99-100-101m, EL 99-99-99m, and EL 100-100-100m in heightened reservoir. Reservoir inflow was simulated by DAWAST model. Annual paddy irrigation requirement was estimated to 33.19M $m^3$ to 2,975ha. Instream flow was allocated to 0.14mm/d from October to April. Operation rule curve was drawn using inflow, irrigation and instream flow requirements data. In case of withdrawal limit reservoir operation using operation rule curve, reduction rates of annual irrigation supply before and after flood control by reservoir were 2.0~4.3% in present size and 1.5~3.6% in heightened size. Reliability on water supply was decreased from 77.3% to 63.6~68.2% in present size and from 81.6% to 72.7~79.5% in heightened size. And reduction rates of water storage at the end of year before and after flood control by reservoir were 7.3~16.5% in present size and 7.7~16.9% in heightened size. But water supplies were done without any water deficiency through withdrawal limit reservoir operation in spite of low flood regulating water level.

• 환경영향평가
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• 제20권4호
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• pp.575-583
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• 2011

In this study, the plausible grid size was estimated to increase for efficiency of reservoir management using 3 dimensional water quality model. To validate utilization of a real time water quality management tool, ELCOM-CAEDYM model was applied to Soyang reservoir in korea. 100m grid size can represent the real topography and take out exact analysis results. $400{\times}400m$ grid can be easily used to analysis because of data capacity. Consequently, the grid size of 200m or 300m was recommended to establish 3D model considering the required simulation time and the irrelevance between horizontal grid size and vertical distribution for temperature and turbidity analysis.

• 설비공학논문집
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• 제14권1호
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• pp.10-20
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• 2002

A dynamic model of a water heater system heated by a heat pump was developed. The water heater system was composed of heat pump and hot water reservoirs. Finite volume method (FVM) was applied to describe the heat exchangers. A new constraint on electronic expansion valve (EEV) or thermostatic expansion valve (TXV) that can control superheat after the evaporator was developed. Dynamic performances were evaluated for various sizes of the reservoir. In order to compare those performances, time scale was normalized by time constant representing the characteristics of reservoir size. Time constant was determined from quasi steady-state simulation of the system. From the simulation, the size of the water heater reservoir was found to have a large influence on the transient performance of the sys- tem. Therefore, the optimization of the reservoir size is needed in a design process.

• 한국수산과학회지
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• 제47권6호
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• pp.1055-1062
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• 2014

Hydroacoustic surveys were conducted for spatio-temporal distribution and size estimation of fish in the Yongdam reservoir, Korea, from April to July 2014. Acoustic data were collected along acoustic transects using a 120 kHz scientific echosounder. The received acoustic data were the in situ acoustic target strength (dB) and nautical area scattering coefficient ($m^2/mile^2$). Data on fish behavioral patterns and size were collected using a DIDSON acoustic camera at stationary stations. Fish were mainly distributed in the center channel and close to the outer Yongdam reservoir. Acoustic density of fish in the summer season were higher than in the spring season. The seasonal vertical distribution pattern of fish aggregations may be strongly related to the vertical temperature structure. The size distribution of fish obtained from an acoustic camera correlated well with the acoustic size of fish from an echosounder.

• 한국농공학회지
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• 제40권4호
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• pp.58-66
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• 1998

Irrigation Reservoir Water Supply Index(IRWSI), which can be applied to the effective supply and management of the irrigation water resources, was developed. IRWSI was formulated as resealed nonexceedance probabilities of two hydrologic components : reservoir storage ratio and precipitation. To generate nonexceedance probability of hydrologic component, it was important to define the optimal one among the various probability distribution function in the state of nature. To define an optimal probability distribution, in this study, four types of probability distribution function were tested by the K-S fitting, and for the calculation of IRWSI, reservoir storage ratio(%) and precipitation used Normal distribution & Gamma distribution, respectively. In this study, the weight coefficients of a and b for each hydrologic component, which is precipitation and reservoir storage ratio, was decided as 0.8 and 0.2, respectively. While some studies changed weight coefficients according to the size of basin area, this study used same values without considering that. From the analysis of drought characteristics, it was found that the IRWSI was sensitive to the size of irrigation area rather than the size of basin area, and the south-eastern region of Korea had been suffered from severe drought damage.

• 한국농공학회지
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• 제42권4호
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• pp.67-75
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• 2000

A simulation model for reservoir sizing was developed to be applied in a region with insufficient hydrological data. Reservoir storage balance equation was formulated on a monthly basis. Gajiyama equation was generalized to estimate monthly reservoir inflow more accurately. Monthly evaporation equation on a reservoir water surface was introduced , which was functioned with monthly mean temperature. Generalized Gajiyama equation was applied to estmate reservoir inflow of the Sayeon dam. Nash-Sutcliffe's model efficiency was 0.793. Using developed model for reservoir sizing, water supply capacity was analyzed with 118.000㎥/day on the Sayeon dam. This showed a reasonable result as compared with 110000㎥/day in other technical report. For general application of developed model, a virtual reservoir was considered and its dta of surface area and volume by elevation was prepared using DEM. Using the model, size of reservoir was determined and water supply capacity was anlayzed on a virtual reservoir.

• 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.

• 생태와환경
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• 제43권2호
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• pp.319-337
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• 2010

본 연구는 우리나라 인공호들에서 연별 계절별 수질변이 특성 및 상 하류 간 수질의 종적구배 특성을 파악하기 위해 2003~2007년의 자료(물환경정보시스템)의 월별, 연별, 공간별(유수대, 전이대, 정수대)의 수질자료를 비교 평가하였다. 10개의 물리적, 화학적, 생물적 수질 변수를 이용하였으며, 인공호들의 일반 수질 특성, 수리수문학적 수질 특성, 시간적 수질변이 특성, 공간적 수질 변이 특성을 분석하였다. 저수면적, 유역면적, 유입량, 방류량을 기준으로 9개의 인공호에 대하여 유사도 분석을 실시하였으며, 그 결과 대형인공호(충주호, 대청호, 소양호), 중형인공호(안동호, 용담호, 주암호, 합천호), 소형인공호(횡성호, 부안호)로 크게 3개 그룹으로 나누어졌고, 유역 크기별로 비슷한 수질 양상을 나타냈다. 홍수의 해(2003년)와 가뭄의 해(2005년)로 대별하여 수질 자료를 분석한 결과, pH, DO, BOD, SS, TN, TP, CHL, EC는 Rz에서 Lz으로 갈수록 값이 감소하였고, SD는 LZ으로 갈수록 값이 증가하였다. 이러한 결과는 인공호내의 영양물질과 부유물질의 침강작용 및 광제한으로 인한 CHL의 감소가 SD 값의 증가에 영향을 미친 것으로 사료되었다. 각 지점별 pH, DO, SS, SD, EC는 가뭄의 해인 2005년에 컸고, BOD, COD, TN, TP, CHL은 홍수의 해인 2003년에 높게 나타났다. 공간적인 수질분포 특성을 분석하기 위하여 9개 인공호의 Rz, Tz, Lz에서의 TN, TP, CHL, SD의 수치를 비교하였다. 그 결과, TN, TP, CHL은 Rz에서 Lz으로 갈수록 침강작용에 의해 그 값이 감소하였고, SD는 반대 양상을 보였다. TN과 TP 사이에서 상관 관계를 분석한 결과, 두 수질 변수 사이의 상관성은 유의하지 않은 것으로 나타났다. 대형 인공호의 CHL-SD 모델에서 Rz, Lz의 경우를 제외하고, TP-CHL, CHL-SD는 유의한 상관성이 있는 것으로 나타났으며, TP-CHL의 상관관계는 중형인공호의 Rz ($R^2$=0.2401, p<0.0001, N=239)에서 유의한 상관성을 보이는 것으로 나타났다. CHL-SD의 상관관계에서도 중형인공호가 가장 높게 나타났으나 TP-CHL의 상관관계와는 반대되는 역상관 관계를 나타냈다. 대청호, 안동호, 횡성호를 Rz, Tz, Lz에서 수질자료를 분석한 결과, 대청호에서 수질자료의 값이 구간별로 큰 변이성을 보이는 것으로 나타났는데, 이는 대청호가 대형인공호로서 구간 간 거리가 멀고, 수심이 깊어 Rz, Tz, Lz의 구간 간 특성이 뚜렷하게 구분된 것으로 사료되었다.

• 상하수도학회지
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• 제26권1호
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• pp.87-95
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• 2012

In this study, the following conclusions were obtained from an investigation of the effect of the simulation time step on the simulation results of the two-dimensional, vertically averaged sediment transport model SED2D and an analysis of the deposited sediment distribution in suspended sediments of reservoirs according to grain size. The simulation time step has a significant effect on the deposited sediment distribution in a reservoir. In particular, if the simulation time step is set to be excessively large, physically invalid results are obtained. Additionally, in order to determine an appropriate simulation time step for SED2D, the selection of a simulation time step that will allow the analysis of the suspended sediment concentration profile at the main points of the simulation domain is necessary. The deposited sediment distribution in a reservoir according to grain size, including suspended sediments of clay, silt, and sand, was successfully simulated. Such information will prove valuable in application to the establishment of efficient management and reduction measures of reservoir sediment deposits.

• 환경생물
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• 제20권1호
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• pp.91-99
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• 2002

오염부하량이 높은 경안천과 오염부하량이 낮은 철원북방 비무장지대내 토교저수지에서 식물플랑크톤의 크기별 현존량과 chlorophyll a농도에 대한 계절적 변화 및 환경요인과의 상호관계를 조사하였다. 또한 식물 플랑크톤의 크기를 고려하여 > $8\mu{m},\;3-8\mu{m},\;<3\mu{m}$ 세포 크기별로 분획하여 현존량과 chl. a 농도를 관찰하였다. 물리.화학적 환경요인은 경안천이 토교저수지보다 높게 나타났다. 식물플랑크톤 현존량은 경안천에서 10배 정도 높았으나 크기별 chl. a의 농도는 두 지점 모두 소형 플랑크톤에서 높은 농도를 보였다. 경안천 식물플랑크톤의 현존량은 대부분 미세형이었지만 chl. a는 부분적으로 극소형 이 우위를 차지하였다. 반면, 토교저수지에서는 현존량은 소형과 미세형이, chl. a는 소형에서 높이 분포하였다. 따라서 영양염 및 물리적 조건이 서로 상이한 수계에서의 식물플랑크톤의 분포는 출현종의 크기를 결정하기도하고 출현종의 특성에 따라 현존량과 chl. a의 불균형적 특성을 유도한다.