• 한국수자원학회논문집
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• 제31권3호
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• pp.303-308
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• 1998

격자기반의 물수지 기법을 이용하여 강우에 의한 지표흐름과 지표하흐름의 시간적 변화와 공간적 분포를 모의할 수 있는 분포형 강우-유출모형을 개발하였다. 본 모형은 제 수문인자들의 격자별 물수지를 계산하여 단방향 흐름경로 알고리듬에 의하여 지표 및 지표하 흐름을 추적한다. 전처리과정으로서 GRASS를 이용하여 모형에 필요한 ASCII 형태의 자료들을 준비하고, 후처리과정으로서 모형의 수행결과인 유역의 유출량, 유출고, 토양수분, 본포 등을 GRASS상에서 도시할 수 있도록 ASCII형태로 출력하도록 구성하였다.

• 한국환경과학회지
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• 제19권10호
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• pp.1211-1217
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• 2010

For an accurate rainfall-runoff simulation in the river basin, it is important to consider not only evaluation of runoff model but also accurate runoff component. In this study long-term runoffs were simulated by means of watershed runoff model and the amounts of runoff components such as upstream inflow, surface runoff, return flow and dam release were evaluated based on the concept of water budget. SSARR model was applied to Daecheong basin, the upstream region of Geum river basin, and in turn the monthly runoff discharges of main control points in the basin were analyzed. In addition, for the purpose of providing the basic quantified water resources data the conceptual runoff amounts were estimated with water budget analysis and the reliability of the observations and the monthly runoff characteristics were investigated in depth. The yearly runoff ratios were also estimated and compared with the observations. From the results of the main control points, Yongdam, Hotan, Okcheon and Daecheong, the yearly runoff ratios of those points are consistent well with data reported previously.

• 상하수도학회지
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• 제22권2호
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• pp.233-238
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• 2008

Recently, rainwater harvesting facilities have increasingly constructed mainly in elementary schools and government buildings. Nevertheless, few methods are available for efficient planning and design of rainwater harvesting facilities by considering the weather conditions and purpose of rainwater management in each site, which may lead to a construction of uneconomic facilities. The current method estimates the size of rainwater storage tank by multiplying the size of building or plottage with a certain ratio and has many limitations. In this study, we first developed a method for planning and design of rainwater storage facilities using $Rainstock^{TM}$ model, which is based on mass balance, and economic analysis. Then, the model was applied for the design of a rainwater harvesting facility in a building with the catchment area of $1,000m^2$. The model calculation indicated that the economic feasibility of rainwater harvesting depends on not only the size of storage tank but also the water usage rate. When the water usage rate is $1m^3/day$, the rainwater harvesting facility is not cost-effective regardless of the size of the storage tank. With increasing the water usage rate, the economical efficiency of the facility was improved for a specific size of the storage tank. Based on the model calculation, the optimum tank sizes for $5m^3/day$ and $10m^3/day$ of water usage rates were $24m^3$ and $57m^3$, respectively. It is expected that the model is useful for optimization of rainwater storage facilities in planning and designing steps.

• 설비공학논문집
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• 제10권5호
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• pp.535-549
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• 1998

A numerical study for performance analysis of a counterflow type forced draft tower and natural draft cooling tower has been performed based on the method using the finite volume method with non-orthogonal body fitted and non-staggered grid system. For solving the coupling problem between water and air, air enthalpy balance, moisture fraction balance, water enthalpy balance, and water mass balance equations are solved with Navier-Stoke’s equations simultaneously. For the effect of turbulence, the standard k-$\varepsilon$ turbulent model is implied in this analysis. The predicted result of the present analysis is compared with the experimental data and the commercial software result to validate the present study, The predicted results show good agreement with the experimental data and the commercial software result. To investigate the influence of the cooling tower design parameters such as approach, range and wet bulb temperature, parametric studies are also peformed.

• 한국수자원학회논문집
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• 제47권1호
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• pp.25-35
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• 2014

본 연구는 TOPLATS 지표해석모형의 물수지와 에너지수지 해석에 따른 수문기상성분 비교를 통해 그 적용성을 평가하는데 목적이 있다. 대상지역은 낙동강유역을 선정하였으며 2003~2012년에 대해 1시간, 1 km의 고해상도 수문기상성분을 산출하였다. 안동댐과 합천댐유역의 관측 일/월단위 댐유입량과 모의유량 비교하여 두 유역의 모의치가 관측값과 유사함을 보였다. 또한 C3와 C4지점의 에너지성분에 대한 Diurnally 분석을 수행한 결과 에너지수지 해석에 따른 순복사량, 현열, 잠열의 일중 변화패턴이 물수지 결과에 비해 정확도가 높은 것으로 나타났다. 특히 C4지점의 순복사량과 잠열의 평균제곱근 오차는 각각 22.18 $W/m^2$와 7.27 $W/m^2$로 매우 낮게 나타났다. 여름철과 겨울철의 계절평균 토양수분과 증발산량은 각각 36.80%, 33.08%와 222.40 mm, 59.95 mm로 산정되었다. 이상의 결과로부터 고해상도의 수문기상성분 모의 시 에너지수지 해석방법을 이용하는 것이 더 합리적인 것으로 판단되며 본 연구 결과는 공간수문기상정보를 활용한 홍수 및 가뭄 등의 재해기상 감시 및 예측에 활용할 수 있을 것으로 판단된다.

• 한국습지학회지
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• 제20권3호
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• pp.210-218
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• 2018

산지습지의 유량 변동을 분석하는 것은 산지습지의 지속적인 관리측면에서 매우 중요하다. 본 연구는 SWAT모형을 이용하여 경남 양산시의 금정산에 위치한 장군습지를 대상으로 물수지 분석을 수행하였다. 강우 및 습지 수위의 관측값을 분석한 결과, 습지 내 양(+)의 수위를 유지하기 위해서는 8일에 한번 10mm이상의 강수가 발생해야 하는 것으로 나타났다. 또한 양산 기상관측소의 수문기상 자료들을 이용하여 2009년에서 2017년까지 물수지 분석을 수행한 결과, 2010년, 2012년, 2015년에 강수량이 상대적으로 적게 내려 습지 내 물 부족이 발생하였다. 특히, 여름철에 강수가 지속적으로 발생하지 않고 단기간에 집중적으로 내려 바로 유출되었기 때문에 물 부족이 발생하는 것으로 분석되었다. 따라서 장군습지의 육화 및 건조화를 방지하기 위해 습지로 유입되는 물길을 확장하고, 작은 둑을 쌓아 물을 저장함으로써 유출되는 양을 감소시키는 등 적정수위가 유지될 수 있도록 다양한 방안들을 마련하여야 할 것으로 판단된다.

• 한국토양비료학회지
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• 제47권1호
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• pp.48-58
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• 2014

In order to evaluate water balance at upland according to RCP8.5 climate change scenario distributed by Korean Meteorological Administration (KMA), we simulated soil moisture using estimation model, called AFKAE0.5 for 66 sites from 2011 to 2020, and established the water balance maps. The amount of annual average precipitation by RCP8.5 scenario was highest in 2016 as recorded 2,062 mm and lowest in 2011 with 1,134 mm. As result of analysis for monthly precipitation and runoff, the amounts of precipitation and runoff have been especially intensive in July in 2014, 2016, 2019, and 2020. Overall, the area of Kyeongbuk and Gyeonggi was estimated more dried status of soil compared with precipitation. Except 2015 and 2020, soil water balance was recorded as negative value in other years which was calculated by subtracting output from input. The status of soil moisture was the most dry in 2020 among those in other years.

• 상하수도학회지
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• 제18권5호
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• pp.656-665
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• 2004

An Ozone reaction model combined with CFD(Computational Fluid Dynamics) technique was developed in this research, in the simulation of ozonation, hydrodynamic behavior as well as reaction model is important because ozone is supplied to treated water as gas ozone. In order to evaluate hydrodynamic behavior in an ozone contactor, CFD technique was applied. CFD technique elucidated hydrodynamic behavior in the selected ozone contactor, which consisted of three main chambers. Three back-mixing zones were found in the contactor. The higher velocities of water were observed in the second and third compartments than that in the first compartment. The flow of the opposite direction to the main flow was observed near the water surface. Based on the results of CFD simulation, the ozone contactor was divided into small compartments. Mass balance equations were established were established in each compartment with reaction terms. This reaction model was intended to predict dissolved ozone concentration, especially. We concluded that the model could predict favorably the mass balance of ozone, namely absorption efficiency of gaseous ozone, dissolved ozone concentration and ozone consumption. After establishing the model, we discussed the effect of concentration of gaseous ozone at inlet, temperature and organic compounds on dissolved ozone concentration.

• 한국농공학회논문집
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• 제54권6호
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• pp.19-28
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• 2012

This study carried out farmland suitability analysis for southern-type garlic cultivation considering soil and temperature as well as water deficit conditions. The spatial extent was limited within the area derived by Kim et al. (2012) using just soil and temperature constraints. Daily soil moisture was simulated using a one-layer soil water balance model at a $100{\times}100m$ grid unit, and then annual water deficit was calculated from 2000 to 2010. The farmland suitability was classified as four steps: best suitable, suitable, possible, and low productive. As a result, total area of best suitable or suitable farmland was about 375,900 ha, and Gimje-si and Haenam-gun were appeared as the largest favorable area for southern-type garlic cultivation. The best suitable or suitable area at Haenam-gun, Goheung-gun, Shinan-gun, Namhae-gun, and Muan-gun, major production regions of southern-type garlic, were extracted as 20,187 ha, 13,018 ha, 4,715 ha, 1,319 ha, and 349 ha, respectively. On the other hand, the result showed that the adoption of sprinkler irrigation systems might be critical in cultivating the southern-type garlic at some regions having poor water balance.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2021년도 학술발표회
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• pp.307-307
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• 2021

개념적 강우-유출모형에서 토양수분과 관련된 물리적 거동은 간략화 된 형태로 강우 및 온도자료를 활용하여 중간변량(state variable)으로 간접적으로 고려되고 있다. 특히 강우-유출모형에 초기함수 조건은 선행함수조건을 고려하여 수문지질학적 평가를 통하여 결정되어야 하나, 일반적으로 가정되거나 모형에서 간략화 된 분석과정을 통해 추정되고 있다. 본 연구에서는 토양의 Water Balance 모형 기반의 개념적 토양수분 추정모형을 활용하였다. 토양수분의 시간적 변동성을 평가하는데 있어서 연속적으로 측정된 In-situ 토양수분 자료를 이용하여 모형의 적합성을 평가하였다. Green-Ampt 방법과 중력식 침투방법과 온도를 활용한 증발산 추정기법을 연계한 토양함수 평가 모형을 개발하였다. In-situ 토양수분 자료와 유역의 강수량 및 온도자료를 이용한 관련 매개변수를 Bayesian 기법을 통해 추정하였으며 매개변수의 민감도를 평가하여 제시하였다. 최종적으로 제안된 모형의 활용측면에서 강우-유출모형의 초기함수 조건으로써의 역할을 평가하였다. 구체적으로 첨두유량 및 유출고와 초기함수조건과의 관계를 제시하고 강우-유출모형에서 활용방안을 제시하고자 한다.