• Water for future
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• v.37 no.3
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• pp.44-49
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• 2004

지표 수문학(surface hydrology)은 강수에 의한 수자원의 발생, 육지나 하천, 그리고 해양에서 발생하는 증발이나 유출 등에 의한 수자원의 손실과 저수지나 댐에서 수위 상승, 토양수분이나 적설의 증가, 그리고 지하수면의 상승 등에 의한 저류량의 증가 등을 종합적으로 설명하는 과학이다. 수자원의 발생이나 손실, 그리고 저류량의 증가를 설명하기 위해서는 질량보존의 법칙과 같은 단순한 물수지 방정식을 이용한다. 그러나, 지표면에서 발생되는 증발이나 식물에 의해서 발생되는 증산 등과 같은 증발산 작용은 에너지를 수반하기 때문에 수문학적인 수지를 규명하기 위해서는 물수지와 에너지수지를 동시에 이용해야 한다.(중략)

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1585-1590
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• 2010

토양으로부터 발생하는 증발과 식물에서 일어나는 증산을 모두 포함하는 증발산은 일반적으로 연구된 물리식과 경험식 등을 이용하여 산정하고 lysimeter 실측 자료를 이용하여 지역 특성에 맞게 검증하는 방법을쓰고 있다. 하지만 이와 같은 방법은 어느 한 점에만 국한되어 적용되기 때문에 공간적인 제약이 있으며 외부환경의 영향을 크게 받는 증발산의 특성상 이를 일반화하는 데에도 어려움이 따른다. 따라서 이러한 점들을 보완하고 해결하기 위해 원격탐사 (Remote Sensing)를 이용하여 넓은 지역에 분포되어 있는 증발산량을 공간적으로 산정하고자 한다. 증발산량은 크게 물수지, 에너지수지 방법을 이용하여 구할 수 있으며, 본 연구에서는 에너지수지 방법을 기반으로 한 원격 이미지 처리 모형을 이용하여 에너지 수지식의 각 항을 이루는 순복사 에너지, 토양열 플럭스, 현열 플럭스와 함께 증발산을 나타내는 잠열 플럭스를 통합적으로 처리하여 산정, 이를 지도로 나타내고 기본적인 통계분석을 실시하였다. 작성된 지도는 유역 내 토지 피복, 식생 분포, 고도 등 외부 인자들의 변화에 따라 증발산량이 공간적으로 어떻게 변화하는지를 알아볼 때 유용하게 쓰일 것이며, 다른 증발산 지도와의 비교를 통해 연구지역에서의 시간 변동성을 파악하는 데에도 도움이 될 것이다.

• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.4
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• pp.77-86
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• 2021

In this study, to use as basic data for the organic waste resource energy incentive system, the energy efficiency is evaluated through the mass balance and energy balance calculation results of the anaerobic digester where food waste, food waste leachate and various organic wastes are treated. As a result of the mass balance analysis for 11 biogasification facilities, it was confirmed that 21.1% of process water and 25.7% of tap water were input in large amounts, excluding organic waste. Accordingly, it accounted for 87.6% of the total effluent of linked treated water. In addition, considering that 15.7% of the total input volume is converted to biogas and the average total solids (TS) is 22%, an average material conversion rate of 75% was confirmed. As a result of the energy balance analysis, the energy conversion rate was confirmed to be 78.5% on average by analyzing the biogas calorific value compared to the potential energy of the influent. The average biogas production efficiency including external energy sources for biogas production was 69.4%, and the biogas plant efficiency to which unused effluent energy was applied was 58.9% on average.

• Water for future
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• v.29 no.4
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• pp.119-129
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• 1996

The daily soil water contents were obtained from the time domain reflectometry (TDR) method and energy balance-water budget approach with eddy correlation at the two small semiarid watersheds of Lucky Hills and Kendall during the summer rainy period. There was a comparison of daily soil water content measured and estimated from these two different approaches. The comparison is valuable to evaluate the accuracy of current soil water content measuring system using TDR and energy balance-water budget approach using eddy correlation method at small watersheed scale. The degree of similarity between the regressions of these two methods of measuring soil water content was explained by determining the correlations between these methods. Simple linear regression analyses showed that soil water content measured from TDR method was responsible for 58% and 63% of the variations estimated from energy balance-water budget approach with eddy correlation at Lucky Hills and Kendall, respectively. The scatter plots and the regression analyses revealed that two different approaches for soil water content measurement at small watershed scale have no significant difference.

• Journal of Korea Water Resources Association
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• v.47 no.1
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• pp.25-35
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• 2014

The objective of this study is to evaluate TOPLATS land surface model performance through comparison of results of water and energy balance analysis. The study area is selected Nakdong river basin and high resolution hydrometeorological components of which spatio-temporal resolution is 1 hr and 1 km are simulated during 2003 to 2013. The simulated daily and monthly depth of flows are well fitted with the observed one on Andong and Hapcheon dam basin. In results of diurnally analysis of energy components, change pattern throughout the day of net radiation, latent heat, sensible heat, and ground heat under energy balance analysis have higher accuracy than ones under water balance analysis at C3 and C4 sites. Especially, root mean square errors of net radiation and latent heat at C4 site are shown very low as 22.18 $W/m^2$ and 7.27 $W/m^2$, respectively. Mean soil moisture and evapotranspiration in summer and winter are simulated as 36.80%, 33.08% and 222.40 mm, 59.95 mm, respectively. From this result, when we need high resolution hydrometeorological components, energy balance analysis is more reasonable than water balance analysis. And this results will be used for monitor and forecast of weather disaster like flood and draught using spatial hydrometeorological information.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.103-103
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• 2023

질량 및 에너지 보존 법칙은 수문현상을 포함한 자연 현상의 기본 법칙이다. 유역에서 물의 질량 보존은 강수량 P가 유출량 Q, 증발산량 E, 그리고 육역저수량변화 ΔS로 분할되는 것(P=Q+E+ΔS)을 의미하며 열 에너지 보존은 순복사에너지 R_n이 잠열 λE, 현열 H, 그리고 지열 G로 분할되는 것(R_n=λE+H+G)을 의미한다. 유역에서 물과 에너지의 분배 과정은 E로 연결되어 있으며 이 두 과정을 포괄적으로 이해하는 것은 기후 및 지표환경의 변화를 예측하고 대비하는데 중요하다. 이 연구에서는 미국 전역의 400여개 유역에 대한 정보를 제공하는 Model Parameter Estimation Project(MOPEX) 데이터를 이용하여 유역의 기후 조건에 따라 물과 에너지의 분배가 어떻게 달라지는지 Budyko 평면에서 분석했다. 장기간에 대해 ΔS와 G는 무시할 수 있다는 가정하에 건조한 유역일수록 P, Q, 그리고 E 모두 작게 나타나는데 P와 Q의 감소폭이 훨씬 크기 때문에 E의 P에 대한 비는 크게 나타났다. 또한 건조한 유역일수록 E는 작고 R_n이 크기 때문에 H가 크게 나타났으며 H가 큰 유역일 수록 유역의 최대 기온과 최저 기온의 차이가 크게 나타났다. 이러한 변화는 동일한 유역내에서 물과 에너지 분배의 시간적 변화로도 나타나고 있다.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.235-236
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• 2003

섬유의 습식 가공은 에너지 집약적 산업이다. 대부분의 에너지는 가공시 사용된 많은 양의 수분을 증발시키고, 건조하는데 소모되어진다. 따라서 거품가공은 물 소비를 감소시켜 에너지를 절약하고 폐수를 감소시키는데 주된 목적이 있다(1). 거품가공은 직물에 부가된 물의 양을 감소시켜 건조단계에서 상당한 에너지 소비(30~80%)를 감소시키는 것으로 알려져 있고(2~3), 최근에는 낮은 wet pick-up율에 의한 가공제 처리의 성능 및 수지의 가교분포에 대한 효과 등에 관한 많은 연구가 이루어지고 있으나 미흡한 점이 많이 보고되고 있다.(4~7) (중략)

• Korean Journal of Agricultural and Forest Meteorology
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• v.13 no.2
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• pp.56-68
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• 2011

Wet canopy evaporation ($E_{WC}$) has been recognized as a significant component of total evapotranspiration, especially in forests and therefore it is critical to accurately assess $E_{WC}$ to understand forest hydrological cycle. In this review, I focused on the measurement methods and evaluating the magnitudes of $E_{WC}$ at diverse forest types (e.g., deciduous, coniferous, mixed, and rain forests). I also present the general issues to be considered for $E_{WC}$ measurements. The commonly used measurement methods for $E_{WC}$ include the water balance, energy balance, and the Penman-Monteith (PM) methods. The magnitudes of $E_{WC}$ ranged from 5 to 54% of precipitation based on the literature review, showing a large variation even for a similar forest type possibly related to canopy structure, rainfall intensity, and other meteorological conditions. Therefore, it is difficult to draw a general conclusion on the contribution of $E_{WC}$ to evapotranspiration from a particular forest type. Errors can arise from the measurements of precipitation (due to varying wind effect) and throughfall (due to spatial variability caused by canopy structure) for water balance method, the measurements of sensible heat flux and heat storage for energy balance method, and the estimation of aerodynamic conductance and unaccounted sensible heat advection for the PM method. For a reliable estimation of $E_{WC}$, the combination of ecohydrological and micrometeorological methods is recommended.

• Composites Research
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• v.35 no.4
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• pp.288-297
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• 2022

This study investigated the effect of addition of zirconia(zirconium oxide) powder on the curing behavior of phenolic resins. The heating rate controlled curing and isothermal curing behaviors of the phenol resin according to the content of the zirconia powder were analyzed. The viscosity and thermal decomposition characteristics of the phenolic resin with the zirconia content were also examind. From the DSC analysis, the degree of cure and the rate of cure were obtained. Finally, the activation energy for the cure reaction were calculated from the DSC data of the zirconia added phenolic resin. As a found, the higher the zirconia content, the longer the curing was delayed and the greater the activation energy required for curing. Additionally, the TGA result that as the content of zirconia increased, less weight loss was observed. The surface tackiness of the Carbon/Phenol prepreg was partially changed according to the zirconia content, but had no significant effect.

• Journal of the Korean earth science society
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• v.43 no.2
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• pp.265-282
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• 2022

This study analyzes the impact of long-range transport of biomass burning emissions from northeastern China on the concentration of particulate matter of diameter less than 10 ㎛ (PM₁₀) in Korea using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem). Korea was impacted by anthropogenic emissions from eastern China, dust storms from northern China and Mongolia, and biomass burning emissions from northeast China between April 4-and 7, 2020. The contributions of long-range PM₁₀ transport were calculated by separating biomass burning emissions from mixed air pollutants with anthropogenic emissions and dust storms using the zeroing-out method. Further, the radiation energy budget over land and sea around the Korean Peninsula was analyzed according to the distribution of biomass burning emissions. Based on the WRF-Chem simulation during April 5-6, 2020, the contribution of long-range transport of biomass burning emissions was calculated as 60% of the daily PM₁₀ average in Korea. The net heat flux around the Korean Peninsula was in a negative phase due to the influence of the large-scale biomass burning emissions. However, the contribution of biomass burning emissions was analyzed to be <45% during April 7-8, 2020, when the anthropogenic emissions from eastern China were added to biomass burning emissions, and PM₁₀ concentration increased compared with the concentration recorded during April 5-6, 2020 in Korea. Furthermore, the net heat flux around the Korean Peninsula increased to a positive phase with the decreasing influence of biomass burning emissions.