• Title/Summary/Keyword: climate(氣候)

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Performance Based Evaluation of Concrete Chloride Diffusion Resistance from Wind Speed-Sunlight Exposure Time Curing Conditions of Climate Change (기후변화에 대한 풍속과 일조시간의 콘크리트 염화물확산 저항성의 성능중심평가)

  • Kim, Tae-Kyun;Cho, Chul-Min;Choi, Ji-Hun;Kim, Jang-Ho Jay
    • Journal of the Korea Concrete Institute
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    • v.28 no.5
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    • pp.601-609
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    • 2016
  • Recently, extreme climate change has been occurring globally not only in the simple form of temperature increases but also in a wide range of extreme climatic events, such as abnormal drought conditions and frequent typhoons. In addition, climate change is delaying the construction period of concrete structures, increasing related economic losses. Forcing construction projects for completion without considering climate change is leading to concrete quality deterioration, poor quality constructions, and consequent casualties and property damage. Therefore, to address these problems and provide a countermeasure to climate change, the present study selected wind speed, and sunlight exposure time as the most important curing conditions among the climate factors affecting concrete structures and examined their effects on the curing and durability of concrete structures. In addition, for the analysis of the experimental results, this study proposed a process of performance based evaluation (PBE) of concrete strength and durability using a method of Satisfaction Curve (SC) generation.

Climate Change Impact on Korean Stone Heritage: Research Trends and Prospect (국내 석조유산의 기후변화 영향: 연구동향과 미래전망)

  • Kim, Jiyoung
    • Journal of Conservation Science
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    • v.32 no.3
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    • pp.437-448
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    • 2016
  • Studies on vulnerability of cultural heritage and adaptation strategy to worldwide climate change have been actively carried out in advanced countries since the late 20th century, and this established a valid research methodology and piled up climate and deterioration dataset in the field of climate change. Meanwhile, we still have tasks to acquire related scientific data despite referencing political researches in Korea. Applying Korean future climate to impact analysis, deterioration of Korean stone heritage is likely prospected to change into complexity in terms of physical, chemical and biological weathering that may bring impacts on conservation business and administrative field of cultural heritage. Further studies will ensure detailed implication of climate change impact on Korean stone heritage by means of down-scaling analysis of areas to local scale and dataset frequency to an hour. It is important to sort out capability and vulnerability of the stone heritage to future environment, and to make an adaption and prevention strategies.

Effect of Climate and Landscape Characteristics on Hydrologic Partitioning and Vegetation Response (기후와 지형 특성이 수문분할과 식생반응에 미치는 영향)

  • Park, Yoonkyung;Choi, Minha;Ahn, Jaehyun;Kim, Sangdan
    • Journal of Korea Water Resources Association
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    • v.46 no.7
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    • pp.735-744
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    • 2013
  • The effect of climate and landscape characteristics on hydrologic partitioning and vegetation response is analyzed in this study. After quantifying hydrologic partitioning using the Horton index, the relation between regional climate characteristics and the Horton index is investigated. In addition, using the comparison between the predictability of the Horton index with only regional climate characteristics and the predictability of the Horton index with landscape characteristics as well as regional climate characteristics, the relative contribution of landscape characteristics on hydrologic partitioning is analyzed. Finally, investigating the predictability of the aridity index and Horton index on the normalized difference vegetation index, the effect of climate and landscape characteristics on vegetation response is estimated.

A High-Resolution Agro-Climatic Dataset for Assessment of Climate Change over South Korea (남한지역 기후변화량 평가를 위한 고해상도 농업기후 자료)

  • Hur, Jina;Park, Joo Hyeon;Shim, Kyo Moon;Kim, Yong Seok;Jo, Sera
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.22 no.3
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    • pp.128-134
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    • 2020
  • The daily gridded meteorological information and climatology with high resolution (30m and 270m) was produced from 94 Automated Surface Observing System (ASOS) of Korea Meteorological Administration (KMA) for the past 50 years (1971-current) by different downscaling methods. In addition, the difference between daily meteorological data and the mean state of past 30 years (1981-2010) was calculated for the analysis of climate change. These datasets with GeoTiff format are available from the web interface (https://agecoclim. agmet.kr). The performance of the data is evaluated using 172 Automatic Weather S tation (AWS ) of Rural Development of Administration (RDA). The data have biases lower than 2.0, and root mean square errors (RMSE) lower than 3.8. This data may help to better understand the regional climatic change and its impact on agroecosystem in S outh Korea.

Comparison of CH4 Emission between Auto Chamber and Manual Chamber in the Rice Paddy (벼논에서 자동 챔버와 수동 챔버를 이용한 CH4 배출량 비교)

  • Jeong, Hyun Cheol;Choi, Eun Jung;Lee, Jong Sik;Kim, Gun Yeob;Lee, Sun Il
    • Journal of Climate Change Research
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    • v.9 no.4
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    • pp.377-384
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    • 2018
  • The chamber method is widely used for measuring methane emission from paddy rice fields. The closed static chamber has advantages of easy installation and removal in the field and low manufacturing cost. However, the manual chamber method requires a lot of labor and has a limited sampling time and frequency. To overcome the disadvantages of the manual chamber, the auto-chamber system is used for measuring methane emission. We compared the differences in methane flux between the auto-chamber and manual chamber. To investigate methane emissions by the two methods, a chamber was installed for each of the following treatments : control without rice straw (NA), spring plowing after autumn rice straw application (SPRA) and autumn plowing after autumn rice straw application (APRA). The total methane emission was lowest in the control and highest in APRA with both methods. There was no significant difference in total methane emission between the methods, but dynamic fluctuation in methane with temperature change was accurately measured in the auto-chamber. Measuring methane emission with an auto-chamber system is expected to reduce uncertainty and increase accuracy, accompanied by labor reduction.

Applicability Analysis of Major Crop Models on Korea for the Adaptation to Climate Change (기후변화 대응을 위한 주요 작물모델의 국내 적용성 분석)

  • Song, Yongho;Lim, Chul-Hee;Lee, Woo-Kyun;Eom, Ki-Cheol;Choi, Sol-E;Lee, Eun Jung;Kim, Eunji
    • Journal of Climate Change Research
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    • v.5 no.2
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    • pp.109-125
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    • 2014
  • Suitable climate condition is essential for stable growth of crops which directly leads to an increase in crop production. Preceding domestic researches mostly used crop models to predict grain or crop yield in relation to climate change. However, the use of various models and input data based on foreign background lowered the reliability for result. Therefore in this study, we evaluated domestic applicability by comparing and analyzing various crop models developed abroad. In addition, we selected models based on the possibility of acquiring input data and suggested domestic applicability.

The Differences of Nitrous Oxide (N2O) Emissions as Crop Presence and Location of Gas Sampling Chambers in Upland (밭토양에서 챔버 위치와 작물체 유·무에 따른 아산화질소 배출량 차이 분석)

  • Jeong, Hyun Cheol;Choi, Eun Jung;Lee, Jong Sik;Kim, Gun Yeob;So, Kyu Ho
    • Journal of Climate Change Research
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    • v.7 no.4
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    • pp.427-432
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    • 2016
  • Nitrous oxide is one of the main sources of greenhouse gases and its concentration has increased from 273 ppb in 1,750 to 315 ppb in 2005. Specially, nitrogen fertilizer used in agricultural soils is considered as an important source of atmospheric $N_2O$ emission. This study was conducted to estimate the difference of nitrous oxide emission as chamber position on furrow and ridge and crop existence in gas sampling chamber on upland. Four treatments used in this experiment were (1) no-fertilizer without crop in chamber on ridge, (2) fertilizer application without crop in chamber on ridge, (3) fertilizer application with crop in chamber on ridge, (4) fertilizer application without crop in chamber on ridge and furrow. Nitrous oxide emission at fertilizer application with crop in chamber on ridge were the highest while were the lowest at no-fertilizer without crop in chamber on ridge. There was no significant difference of nitrous oxide emission by chamber position, but total emission by crop existence in chamber was significant difference. Therefore, in order to estimate greenhouse gases emission using chamber method in upland, it should be considered in correlation with crop existence in chamber and characteristic changes like as the soil moisture, microbial flora by crop growth stage.

The Analysis of Differences by Improving GHG Emission Estimation Methodology for Agricultural Sector in Recent 5 Years (최근 5년간 농업부문 온실가스 산정방법 개선과 그에 따른 배출량 차이 분석)

  • Jeong, Hyun Cheol;Choi, Eun Jung;Lee, Jong Sik;Kim, Gun Yeob;Lee, Sun Il
    • Journal of Climate Change Research
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    • v.8 no.4
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    • pp.347-355
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    • 2017
  • Methane and nitrous oxide are main greenhouse gases from agricultural system and their global warming potential are 25 and 258 times stronger than that of $CO_2$, respectively. In 2016, the emission was $21,290Gg\;tone\;CO_2-eq$. which was emitted from agriculture sector and about 3.1% of total GHG emission of Korea. Those guidelines that were published by IPCC have methodology for GHGs emission calculation as well as emission factor and so on. For recent 5 years, GHGs emissions in Korea have calculated by MRV which has been improved every year based on IPCC guidelines. Analysis as estimating method improvement showed that the methane emissions from rice cultivation were the lowest on 2012 methodology, and the highest on 2014 methodology. On the other hand, the emissions of agricultural soils were the lowest on 2015 methodology and the highest on 2012 methodology. Total emissions from agriculture sector were the lowest on 2015 methodology and the highest on 2012 methodology. Compared with 2016 methodology, the GHGs emitted as few as $-1,865Gg\;tone\;CO_2-eq$ and as many as $2,717Gg\;tone\;CO_2-eq$. GHGs emissions can vary greatly, depending on how to use the emission factor and activity data. Therefore, it need constantly a detailed analysis for methodology and GHGs emission in the future.

The Direction and Implication of Urban Development in the Age of Response Climate Change (기후변화 대응시대의 도시개발방향과 시사점)

  • Oh, Eun-Yeol
    • Journal of Industrial Convergence
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    • v.17 no.1
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    • pp.33-39
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    • 2019
  • The purpose of this study was to present the direction and implications of urban development in relation to climate risk factors and environment for practical implementation of urban development in response to climate change. The research method was carried out through a qualitative data survey and analysis. As a result of the study, the direction of urban development according to the climate risk factors emphasized the importance of preparing conditions for urban development by establishing a damage prevention system for natural disasters and analyzing the risk of natural disasters by conducting analysis of the impact and vulnerability of climate change in urban planning. The direction of urban development on the environmental side suggested the need for the promotion of public transport oriented development (TOD) in the form of urban planning to realize sustainable and practical urban development. Future research directions will need to be supplemented with more quantitative and empirical findings.

Estimation of Road Sections Vulnerable to Black Ice Using Road Surface Temperatures Obtained by a Mobile Road Weather Observation Vehicle (도로기상차량으로 관측한 노면온도자료를 이용한 도로살얼음 취약 구간 산정)

  • Park, Moon-Soo;Kang, Minsoo;Kim, Sang-Heon;Jung, Hyun-Chae;Jang, Seong-Been;You, Dong-Gill;Ryu, Seong-Hyen
    • Atmosphere
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    • v.31 no.5
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    • pp.525-537
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    • 2021
  • Black ices on road surfaces in winter tend to cause severe and terrible accidents. It is very difficult to detect black ice events in advance due to their localities as well as sensitivities to surface and upper meteorological variables. This study develops a methodology to detect the road sections vulnerable to black ice with the use of road surface temperature data obtained from a mobile road weather observation vehicle. The 7 experiments were conducted on the route from Nam-Wonju IC to Nam-Andong IC (132.5 km) on the Jungang Expressway during the period from December 2020 to February 2021. Firstly, temporal road surface temperature data were converted to the spatial data with a 50 m resolution. Then, the spatial road surface temperature was normalized with zero mean and one standard deviation using a simple normalization, a linear de-trend and normalization, and a low-pass filter and normalization. The resulting road thermal map was calculated in terms of road surface temperature differences. A road ice index was suggested using the normalized road temperatures and their horizontal differences. Road sections vulnerable to black ice were derived from road ice indices and verified with respect to road geometry and sky view, etc. It was found that black ice could occur not only over bridges, but also roads with a low sky view factor. These results are expected to be applicable to the alarm service for black ice to drivers.