• Journal of Climate Change Research
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• v.9 no.4
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• pp.423-433
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• 2018

Particulate matter air pollution is a serious problem affecting human health and visibility. The variations in $PM_{10}$ concentrations are influenced by not only local emission sources, but also atmospheric circulation conditions. In this study, we investigate the temporal features of $PM_{10}$ concentrations in South Korea and the atmospheric circulation patterns associated with high concentration episodes of $PM_{10}$ during winter (December-January-February) 2001-2016. Based on those analyses, a Korea Particulate matter Index (KPI) is developed to represent the large-scale atmospheric pattern associated with high concentration episodes of $PM_{10}$. The atmospheric patterns are characterized by persistent high-pressure anomalies, weakened lower-level north-westerly anomalies, and northward shift of the upper-level meridional wind anomalies near the Korean Peninsula. To evaluate the change in occurrence of high concentration episodes of $PM_{10}$ under a possible future warmer climate, we apply KPI analysis to CMIP5 climate simulations. Here, historical and two representative concentration pathway (RCP) scenarios (RCP 4.5 and RCP 8.5) are used. It is found that the occurrence of atmospheric conditions favorable for high $PM_{10}$ concentration episodes tends to increase over South Korea in response to climate change. This suggests that large-scale atmospheric circulation changes under future warmer climate can contribute to increasing high $PM_{10}$ concentration episodes in South Korea.

• Journal of Korea Water Resources Association
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• v.47 no.4
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• pp.385-396
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• 2014

Lately, more frequent typhoons cause extensive flood and wind damage throughout the summer season. In this respect, this study aims to develop a probabilistic clustering model that uses both typhoon genesis location and trajectories. The proposed model was applied to the 197 typhoon events that made landfall in the Korean peninsula from 1951 to 2012. We evaluate the performance of the proposed clustering model through a simulation study based on synthetic typhoon trajectories. The seven distinguished clusters for typhoons affecting Korean peninsula were identified. It was found that most of typhoon genesis originated from a remote position ($10^{\circ}{\sim}20^{\circ}N$, $120^{\circ}{\sim}150^{\circ}E$) near the Equator. Cluster, type B can be regarded as a major track due to the fact that its frequency is approximately about 25.4% out of 197 events and its direct association with strong positive rainfall anomalies.

• Journal of Korea Water Resources Association
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• v.38 no.11
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• pp.955-962
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• 2005

Even though the runoff volume is very sensitive to the antecedent soil moisture condition (AMC), the general rainfall-runoff analysis in Korea has accepted, without careful consideration of its applicability, the AMC classification of the Soil Conservation Service (SCS, 1972). In this study, by following the development procedure of SCS Curve Number (CN), the rainfall-runoff characteristics of the Jangpyung subbasin of the Pyungchang River Basin were analyzed to estimate the CN and evaluate the AMC classification of currently being used. As results, CN(I), CN(II), and CN(III) were estimated to be 72.1, 79.3, and 76.7, respectively. Among them CN(II) was found to be similar to the other reports but the other two were totally different from those of theoretically estimated. However, it is difficult to evaluate the AMC with CN, rather the frequency of each AMC could be a better indicator for its validity. This study developed the histogram of AMC and compared the frequency of each AMC. hs results we found that the criterion for AMC-III should be increased, Hut that for AMC-I decreased.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1334-1338
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• 2008

최근 전 세계적으로 효율적인 유역내 수자원을 관리하기 위한 목적에서 하천 및 유역의 장기유출분석에 관한 많은 연구가 이루어지고 있는데 이러한 장기유출은 단기유출과 달리 인위적인 요소에 의해 많은 영향을 받는다. 인위적인 요소 중에 가장 대표적인 것이 저수지와 같은 저류시설물이다. 따라서 강우-유출모형을 통한 장기유출량 모의시에 이러한 인위적인 저류시설물의 영향을 모두 시스템화하여 유출모형에 반영하는 것은 바람직하나 현실적으로 매우 어려운 실정이다. 따라서 본 연구는 소규모 수리시설물이 장기유출에 끼치는 영향에 대해 시 공간적으로 상세히 분석하고 또한 분석된 결과를 토대로 장기유출 모형에 소규모 수리 시설물의 영향을 반영할 수 있도록 모형을 재구성함으로서 유역의 장기유출에 대한 모의결과의 신뢰도를 증진시키는 것이 본 연구의 목적이다. 본 연구에서는 금강유역의 소규모 수리시설물 현황을 파악하고 각 수리시설물별로 하천유량에 끼치는 영향을 분석한 후, 수리시설물의 영향을 고려할 수 있도록 SSARR모형을 구축하였다. 수리시설물에 의한 영향평가를 실시한 결과, 공간적으로는 저수지가 많이 분포한 소유역에서, 시기적으로는 강우가 풍부했던 2003년을 제외한 2/4분기에서 에러발생빈도가 크게 나타났다. 따라서 본 연구에서는 수리시설물의 영향평가를 토대로 유출량과 수리시설물의 상관식을 유도하였으며 이를 이용한 주요지점 유출량을 모의하였다. 그 결과 용담댐, 수통, 호탄, 옥천 및 대청댐지점의 모의유량이 상대적으로 수리시설물을 고려하지 않은 경우보다 에러와 오차가 크게 감소하였다.

• Journal of Conservation Science
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• v.32 no.4
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• pp.491-500
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• 2016

Fog is atmospheric in which tiny drops of water vapor are suspended in the air near the ground. Its form, occurrence, etc., change according to the temperature, relative humidity, wind and geographical features of the space around it. In particular, fog tends to occur near a source of water because of temperature and relative humidity difference. These days, climate change is increasingly affecting the occurrence of fog. Therefore the purpose of this study was to investigate how fog affects materials that are part of our cultural properties through outdoor exposure tests and artificial degradation. The degradation evaluation of materials as a function of fog occurrence frequency, showed that the color of metals changed noticeably, whereas dyed silk and Dancheong showed degradation on the surface and color differences but no particular tendencies. Therefore, damage prediction by color differences as a function of fog occurrence frequency was based on metal samples, which showed constant color differences. Through a comparison of the predictive value and color difference by outdoor exposure, the accuracy and applicability of the damage prediction formula was confirmed. If a more complex damage prediction formula is created, it is expected that prediction of the degree of material damage in the field would be possible.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.1
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• pp.75-83
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• 2020

This study investigated the effects of El Niño and La Niña on coastal upwelling in the East Sea of Korea using long-term (1967-2017) water temperature observation data and Oceanic Niño Index (ONI). As a result of time series analysis of water temperature, the occurrence frequency of summer coastal upwelling was the highest in the southeastern (Ulgi ~ Gimpo) coast. In 1987-1988 and 1997-1998, when the annual fluctuations of ONI plunged more than 2.5, the water temperature in whole coast areas of the East Sea (Busan ~ Goseung) rose by 4 ~ 7 ℃. The temperature structure of the East Sea coastal water was different when El Niño was strong with ONI above 1.5 and La Niña with strong ONI below -0.8. When El Niño is strong, the water temperature anomaly in coastal waters is negative. This is due to the strong baroclinic tilting and the formation of shallow temperature stratification in the coastal waters. The strong La Niña season is opposite to the strong El Niño season, whereas the water temperature anomaly is positive. In addition, the baroclinic tilting is weaker than the time of strong El Niño and the temperature stratification is formed deeper than the time of strong El Niño. The formation of temperature stratification at shallow depths when El Niño is strong can increase the probability of occurrence coastal upwelling caused by southerly winds in the summer season. On the contrary, when La Niña is strong, occurrence of coastal upwelling is less likely even if the southerly wind blows continuously. This is because the temperature stratification is formed at deeper than when El Niño is strong.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.4
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• pp.352-361
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• 1990

The reducing effect of wind injury was investigated using several wind-break nets in Youngdeok province where cold-wind damage is often occurred during rice growing season. The white-head damage of rice have been often occurred by typhoon during the period between August 15 to September 10 in the cold wind area of the eastern coastal during the last 11 years (1979-1989). This may suggest that the critical period for heading will be by August 15 in the regions. High evaporation coefficient, more than 250 due to typhoon passage over the regions resulted high injury of white head. Generally, the wind injury have been caused by warm and dry westerlies through Fohn apperance in Taebaeg mountains and by cool-humid wind which blows from coast to inland. The frequency of occurrence of the two types of typhoons were 25, 20%, respectively during rice cultivation. The instalation of wind-break net significantly reduced the wind blowing speed, depending on the net mesher with the higher effect in dence net. The distances between the net and cropping area also affect the wind speed: 23% reduction at 1m distance. 34% at 10m and 28% at 20m, respectively. The reducing effect was also observed even at 10 times height of the wind-break net. The instalation of wind-break net gave several effects on climate factor, showing that temperature increased by 0.8$^{\circ}C$(maximum), 0.7$^{\circ}C$(minimum), 0.6$^{\circ}C$(average) : water temperatures increased by 0.5$^{\circ}C$(maximum), 0.6$^{\circ}C$(minimum), 0.5$^{\circ}C$(average) : soil temperature increased 0.4$^{\circ}C$. The earlier heading and increasing growth rate, use of light, culm length, panicle number per hill, spikelet number per panicle, fertility and 1,000 grain weight were observed in the fields with the wind-break nets resulting in 10-15% increase in rice yield using 0.5${\times}$0.5cm nets. The increasing seedlings per hill gave higher grain yield by 13% in the cold wind damage regions of eastern coastals. and the wind-break was more significant in the field without the wind-break net. Wind injury of rice plant in the cold wind regions of eastern coastals in korea could be reduced by selection of tolerant varieties to wind injury, adjustment of transplanting time, and establishment of wind-break nets.

• Journal of Korea Water Resources Association
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• v.41 no.8
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• pp.785-795
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• 2008

The swell is a major cause of interruption for the activity in a port and the ship navigation in coastal waters, coastal geographical changes, and the disaster with a loss of lives. However, many researches about the observation and the prediction of swells have not been conducted actively due to the difficulties to collect and synthesize the massive amount of long term field data for waves and meteorological information. In this study, the internet-based realtime monitoring system(Fieldbox) was developed to collect the wave data. The characteristics and main components of swells occurred in Korea were analyzed using wave data observed through the Fieldbox and the meteorological data collected by the KMA(Korea Meteorological Administration) and NASA(National Aeronautics and Space Administration). The characteristics of the swell generation patterns were analyzed using the monthly data of the Kwangan Tower between 2004 and 2006 to estimate the specific features such as sources and locations of swells generated in Korea.

• Journal of Energy Engineering
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• v.23 no.3
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• pp.58-65
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• 2014

The study examined the post-monitoring programs under the energy efficiency labeling program in developed countries. This study suggests a few solutions to improve the post-monitoring activities under the program. First, samples should be selected from each category for the post-monitoring activities, taking account of the consumer's continuous buying behavior. Second, it is necessary to check of detailed label contents and to perform the frequent monitoring the reinforcement of the measurement of items which have violated labeling more than once over the past few years. Last, this study suggests that the entire post-monitoring process should be disclosed and be posted on the websites on the internet in general.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.590-590
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• 2016

최근 기후변화로 인하여 풍수해의 발생빈도가 높아짐에 따라 자연재해 예측에 대한 연구가 활발히 진행되는 추세이다. 또한 풍수해와 관련하여 정부 및 지자체에서 재해지도를 작성하고 있으나 각 기관의 특성에 따라 개별적으로 재해지도를 시스템으로 제공하고 있다. 결국 호우, 산사태, 바람 등 각각의 재해에 대해 여러 시스템에서 자료를 제공하고 있기 때문에 필요자료, 지역 등에 따라 사용자가 시스템을 찾아 이용해야하는 불편이 존재하며 전국이 아닌 일부 지역만 제한적으로 제공되고 있다. 또한, 각 기관에서 제공되는 자료의 종류와 제공형태가 시스템별로 다르기 때문에 사용자가 추가적인 작업을 해야하는 단점이 존재한다. 국민안전처에서 추진하는 '풍수해저감 종합계획'의 활성화를 위해서 통합적인 재해지도 제공 시스템이 필요하다. 따라서 본 연구에서는 재해관련기관에서 현재 제공되고 있는 시스템에 대한 활용자료, 구성도 등의 조사, 분석을 통한 연계 전략 수립을 위한 연구를 진행하였다. 또한 풍수해 피해예측지도의 공동활용을 위한 표준연계모듈 적용방안을 제시하여 추후 풍수해 피해예측지도 구축 및 피해예측지도 작성에 활용 가능할 것으로 기대된다.