• 한국농공학회지
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• 제29권3호
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• pp.125-137
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• 1987

The purpose of this paper is to examine some difficulties in water management of agricultural reservoirs in Korea, for there are approximately more than 15,000 reservoirs which are now being utilized for the purpose of irrigation, along with the much amount of expenses and labors to be invested against droughts and floods periodically occurred. Recently, the effective use of water resources in the agricultural reservoirs with a single purpose, is becomming multiple according to the alterable environment of water use. Therefore, the task to allocate agricultural water rationally and economically must be solved for the multiple use of agricultural reservoirs. On the basis of the above statement, this study aims at suggesting the rational method of water management by introducing an optimal technique to allocate the water in an existing agricultural reservoir rationally, for the sake of maximizing the economic effect. To achieve this objective, a reservoir, called "0-Bongje" as a sample of the case study, is selected for an agricultural water development proiect of medium scale. As a model for the optimum allocation of water in the multi-purpose use of reservoirs a linear programming model is developed and analyzed. As a result, findings of the study are as follows : First, a linear programing model is developed for the optimum allocation of water in the multi-purpose use of agricultural reservoirs. By adopting the model in the case of reservoir called "O-Bongje," the optimum solution for such various objects as irrigation area, the amount of domestic water supply, the size of power generation, and the size of reservoir storage, etc., can be obtained. Second, by comparing the net benefits in each object under the changing condition of inflow into the reservoir, the factors which can most affect the yearly total net benefit can be drawn, and they are in the order of the amount of domestic water supply, irrigation area, and power generation. Third, the sensitivity analysis for the decision variable of irrigation which may have a first priority among the objects indicate that the effective method of water management can be rapidly suggested in accordance with a condition under the decreasing area of irrigation. Fourth, in the case of decision making on the water allocation policy in an existing multi-purpose reservoir, the rapid comparison of numerous alternatives can be possible by adopting the linear programming model. Besides, as the resources can be analyed in connection with various activities, it can be concluded that the linear programing model developed in this study is more quantitative than the traditional methods of analysis. Fifth, all the possible constraint equations, in using a linear programming model for adopting a water allocation problem in the agricultural reservoirs, are presented, and the method of analysis is also suggested in this study. Finally, as the linear programming model in this study is found comprehensive, the model can be adopted in any different kind of conditions of agricultural reservoirs for the purpose of analyzing optimum water allocation, if the economic and technical coefficients are known, and the decision variable is changed in accordance with the changing condition of irrigation area.

• 대한토목학회논문집
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• 제30권2B호
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• pp.121-135
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• 2010

본 연구에서는 연구(I)에서 구축한 고도, 기상, 토지이용, 토양, 식생과 같은 기본 입력자료와 공도 수위관측소 상류유역을 대상으로 유역내에 포함되어 있는 농업용 저수지인 고삼과 금광저수지의 저수위, 저수량, 내용적 곡선 자료들을 이용하여 SLURP 모형의 물리적 매개변수들과 저수지의 방류량을 조정하여 저수지의 저수위와 유역 유출량을 검 보정하였다. 한편, 연구(I)에서의 편이보정과 CF 다운스케일기법에 의한 CCCma CGCM2 A2, B2 시나리오의 미래 기후자료, 개선된 CA-Markov 기법에 의한 미래 토지이용자료, 월 NDVI와 평균온도와의 선형회귀식에 의한 미래 식생자료 등을 모형에 입력하여 미래 기후변화에 따른 저수지 저수량과 유입량에 미치는 영향을 평가하고 전체적인 유역 수문(증발산량, 토양수분, 지하수충진량, 유출량)의 변화를 평가하였다. 저수지의 미래 저수량과 유입량은 가을시기에 크게 감소하는 것으로 평가되었고, 유역의 미래 연유출량, 토양수분, 지하수충진량은 다소 감소하고, 증발산량은 크게 증가하는 것으로 전망되었다. 마지막으로, 미래 기후변화, 토지이용변화와 식생변화 중 어떠한 요소가 미래의 농업용 저수지의 유입량, 저수량 및 하천유역의 수문에 큰 영향을 미치는 지를 평가하기 위해 각 요소의 기여도를 분석한 결과, 기후변화가 가장 크게 기여하는 것으로 평가되었다.

• 한국대기환경학회지
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• 제26권3호
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• pp.330-338
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• 2010

In this study, removal characteristics of nitrogen oxides $(NO_x)$ from road transport by using peat as the packing media for biodegradation have been investigated in the long term. Physicochemical and biological treatment of peatmixed media eliminates any requirement to use chemical substances and also facilitates the biodegradable actions of microorganism. Safe biodegradation of pollutants, no need to apply additional microbes owing to their active growth, and no generation of secondary pollutants were found in this experiment. It was concluded that average removal efficiencies of nitric oxide (NO) and nitrogen dioxide $(NO_2)$ were 80% and 97% respectively with respect to the linear velocity 35~40 mm/s and 0.3 ppm ozone concentration in the long period operation. Inflow concentration of nitric oxide over 0.05 ppm was suitable when pretreated with ozone. Non-ozone stage was performed with linear velocity 20~100 mm/s and then the average removal efficiency of nitric oxide and nitrogen dioxide were 38% and 94% respectively. Other results showed that the apparent static pressure was raised with increases in applied water content and aerial velocity in mixed media during fan operation.

• Journal of Ecology and Environment
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• 제40권2호
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• pp.125-135
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• 2016

Background: The objectives of this study were to establish a swimming capability model for largemouth bass using the FishXing (version 3) program, and to determine the swimming speed and feasibility of fish passage through a waterway tunnel. This modeling aimed to replicate the waterway tunnel connecting the Andong and Imha Reservoirs in South Korea, where there is a concern that largemouth bass may be able to pass through this structure. As largemouth bass are considered an invasive species, this spread could have repercussions for the local environment. Results: Flow regime of water through the waterway tunnel was calculated via the simulation of waterway tunnel operation, and the capability of largemouth bass to pass through the waterway tunnel was then estimated. The swimming speed and distance of the largemouth bass had a positive linear function with total length and negative linear function with the flow rate of the waterway tunnel. The passing rate of small-size largemouth bass (10-30 cm) was 0%at a flow of $10m^3/s$ due to rapid exhaustion from prolonged upstream swimming through the long (1.952 km) waterway tunnel. Conclusions: The results of FishXing showed that the potential passing rate of large size largemouth bass (>40 cm) through the waterway tunnel was greater than 10%; however, the passage of largemouth bass was not possible because of the mesh size ($3.4{\times}6.0cm$) of the pre-screening structures at the entrance of the waterway tunnel. Overall, this study suggests that the spread of largemouth bass population in the Imha Reservoir through the waterway tunnel is most likely impossible.

• 대한조선학회논문집
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• 제30권3호
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• pp.29-40
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• 1993

본 연구는 정수면으로 부터 얕게 잠겨 항주하는 3차원 수중익에 의한 비선형 조파현상의 특성규명을 위한 기초연구로서 수중익이 예인수조안에서 일정속도로 항주할 때 자유표면에 발생하는 비선형 파형의 특성과 수중익에 작용하는 유체력을 계산하기 위한 수치해법의 개발을 목적으로 하였다. 수치해법으로는 변분원리에 기초한 유한요소법올 사용하였으며 수중익 근처에서는 비선형 자유표면조건을 엄밀하게 만족시켰고 수중익으로 부터 충분히 떨어진 영역에서는 종래의 선형화된 자유표면 경계조건을 만족시켰다. 수치해법의 계산효율을 높이기 위하여 비선형영역과 선형영역 사이에 인위적인 비선형-선형 완충영역을 도입하여 계산영역을 크게 줄였다. 수중익을 간단한 직사각형 보오텍스계로 표현하여 유속과 몰수길이, 보오텍스의 세기 및 분포의 변화에 따른 비선형 파형의 특성을 조사하였으며 특히 자유 보오텍스선이 비선형 파형에 미치는 영향을 파악하였다. 파동에 의하며 수중익에 유기되는 속도성분들의 크기 및 분포, 양력 및 유기항력에 대한 계산을 수행하여 자유표면의 비선형성에 의한 영향을 규명하였다.

• 한국습지학회지
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• 제21권3호
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• pp.236-243
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• 2019

현재까지 많은 수문 시계열은 전통적인 선형 모형을 이용하여 분석되고 예측되어 왔다. 하지만, 자연현상과 수문시계열의 패턴 및 변동과 관련하여 비선형적 구조의 증거가 발견되고 있다. 따라서 시계열 분석 및 예측을 위한 기존의 선형 모형은 비선형적 특성에 적합하지 않을 수 있다. 본 연구에서는 미국 플로리다 코코아 지역 인근에 있는 St.Johns 강의 일유량 자료에 대한 카오스 분석을 수행하였고, 그 결과 낮은 차원의 비선형 동역학적 특성을 가진 흥미로운 결과가 나타났지만 한국의 소양강댐 일유량 자료는 확률적 특성을 보여주었다. 카오스 특성을 토대로한 DVS(결정론적 vs 추계학적) 알고리즘을 이용해 두 시계열 시스템의 특성을 파악하였고 단기 예측을 수행하였다. 또한 본 연구에서는 일 유량 시계열 예측을 위해 인공신경망 방법을 사용하였고, DVS 알고리즘에 의한 예측을 비교 분석하였다. 분석 결과, 카오스 특성을 갖는 시계열 자료가 보다 정확한 예측성을 보였다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제15권1호
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• pp.39-49
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• 2010

Drilling at unconsolidated layer can make the aquifer disturbed and reduce a productivity of groundwater well. Surge block and air surging were applied to a pumping well located in Jeungsan-ri, Changnyung-gun, to improve a well efficiency by removing clogging and fine-grained slime. Two experimental log-linear equations, $y_1=-0.1769\;ln(x_1)+0.4960$ and $y_2=-84.3358\;ln(x_2)+512.8162$, were proposed in this site, in which $x_1$ and $x_2$ are the number of surging event, $y_1$ is the amount of slime, and $y_2$ is a recovery time of groundwater level after air surging. Well loss exponent (P) decreased after surging, from 3.422 to 1.439, and the groundwater inflow from aquifer happened in all directions around a well with gradually increasing the homogeneity in a local aquifer's hydraulic property. It was revealed that long-term well development should be done in the pumping well which is located in unconsolidated sediments to increase a well productivity.

• 한국물환경학회지
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• 제26권6호
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• pp.994-999
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• 2010

The toxin of Cyanobacteria (blue-green algae) during summer season has been a problem and early prevention should be considered. A variety of methods can be used to forecast algal blooms and this study aims at examining feasibility of chlorophyll-a. The real-time data were collected by automatic water quality monitoring system (AWQMS) in Daecheong reservoir and invalid data were sorted by experts. And then, the sorted data were filled using linear interpolation. When the concentration of chlorophyll-a increased by $15mg/m^3$, water temperature and pH exceeded $26.8^{\circ}C$ and 9.5 respectively. As a result of correlation between chlorophyll-a and other parameters(i.e. water quality items and hydrological data), temperature (r=0.502 - 0.574), pH (r=0.583 - 0.681), total organic carbon (TOC, r=0.583 - 0.681) comparably had higher values. Meanwhile, the data around a day or two showed the highest correlation. In addition, chlorophyll-a is considered to be significantly effected by precipitation and inflow.

• 한국해양학회지
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• 제24권1호
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• pp.29-38
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• 1989

동해 해수순환의 특징은 대한해협으로부터 유입된 난수가 동한난류를 형성하여 한국연안을 따라 북상한 후 다시 외해로 분리되어 나간다는 것과 북쪽에서부터 연안을 따라 남하하는 북한한류가 형성하는 반시계 방향의 순환류가 동해 북부에 존재한다는 사실일 것이다. 본 논문에서는 이러한 사실을 설명하기 위하여 간단한 역학적 모델을 수립하였다. 동해 해수순환을 기본적으로 유입-유출 형태라 한 후 여기에 해양-대기 열 교환을 적용하였으며 해수혼합에 의한 열의 소멸, 마찰에 의한 운동량의 소멸도 고려하였다. 결과에 의하면, 상기의 순환특징은 열역학적 요인에 의하여 기인됨이 밝혀졌다. 또한, 열교환의 정도에 따라 여러가지 순환형태가 나타날 수 있음도 보였다.

• 한국환경과학회지
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• 제13권12호
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• pp.1041-1048
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• 2004

In this study the results of optimal water supply analysis by operating constraints of reservoirs during drought period are as follows. During drought period, water supply reliability is possible about $97\~61{\%}$ by CASE 1-CASE 5. Water supply reliability is possible about $97.3{\%}$ in case of the Andong dam and $87.7{\%}$ in case of the Imha dam by CASE 3. Also, under the constraints of CASE 4, water supply reliability is possible about $87.5{\%}$ in case of the Andong dam and $73.3{\%}$ in case of the Imha dam. The reason what low of available water supply ratio is decreased inflow of Imha dam. When compare standard deviation of average storage with standard deviation of storage, stable storage can be secured during successive drought period. And it also can minimize shortage of water during drought. therefore, it is impossible that reservoir supply sufficient water but change of operating condition is better than pervious on that followed by full reservoir level. It is need that the study for optimal water supply during drought period has to be continued.