• Title/Summary/Keyword: Climate changes

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Changes in the External Heat Environment of Building Evaporative Cooling Systems in Response to Climate Change (기후변화 대응 건축물 기화냉각시스템 적용에 따른 외부 열환경 변화 연구)

  • Yoon, Yong-Han;Kwon, Ki-Uk
    • Journal of Environmental Science International
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    • v.27 no.12
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    • pp.1261-1269
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    • 2018
  • The purpose of this study was to investigate changes in the external thermal environment, following the application of evaporative cooling systems in buildings, in response to climate change. In order to verify changes in the external thermal environment, a T-test was performed on the microclimate, Thermal Comfort Index (TCI), and building surface temperature. Differences in microclimate, following the application of the evaporative cooling system in the building, were significant in terms of temperature and relative humidity. In particular, temperature decreased by more than 7% when the evaporative cooling system was applied. According to the results of the Thermal Comfort Index analysis, the Wet-Bulb Globe Temperature (WBGT) was below the limit of outdoor activities, indicating that outdoor activities were possible. The Universal Thermal Climate Index (UTCI) values were within the very strong heat stress range when the evaporative cooling system was not applied, When the system was applied, the UTCI values were within the strong heat stress range, indicating that they were lowered by one level. The building surface temperature decreased by ~10% or more when the evaporative cooling system was applied, compared to when it was not applied. Finally, the outside surface temperature of the building decreased by ~12% or more when the system was applied, compared to when it was not applied. We conclude that the energy saving effect of the building was significant.

Flood Frequency Analysis with the consideration of the heterogeneous impacts from TC and non-TC rainfalls: application to daily flows in the Nam River Basin, South Korea

  • Alcantara, Angelika;Ahn, Kuk-Hyun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2020.06a
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    • pp.121-121
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    • 2020
  • Varying dominant processes, including Tropical Cyclone (TC) and non-TC rainfall events, have been known to drive the occurrence of precipitation in South Korea. With the changes in the pattern of the Earth's climate due to anthropogenic activities, nonstationarity or changes in the magnitude and frequency of these dominant processes have been separately observed for the past decades and are expected to continue in the coming years. These changes often cause unprecedented hydrologic events such as extreme flooding which pose a greater risk to the society. This study aims to take into account a more reliable future climate condition with two dominant processes. Diverse statistical models including the hidden markov chain, K-nearest neighbor algorithm, and quantile mappings are utilized to mimic future rainfall events based on the recorded historical data with the consideration of the varying effects of TC and non-TC events. The data generated is then utilized to the hydrologic model to conduct a flood frequency analysis. Results in this study emphasize the need to consider the nonstationarity of design rainfalls to fully grasp the degree of future flooding events when designing urban water infrastructures.

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Future Projection of Extreme Climate over the Korean Peninsula Using Multi-RCM in CORDEX-EA Phase 2 Project (CORDEX-EA Phase 2 다중 지역기후모델을 이용한 한반도 미래 극한 기후 전망)

  • Kim, Do-Hyun;Kim, Jin-Uk;Byun, Young-Hwa;Kim, Tae-Jun;Kim, Jin-Won;Kim, Yeon-Hee;Ahn, Joong-Bae;Cha, Dong-Hyun;Min, Seung-Ki;Chang, Eun-Chul
    • Atmosphere
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    • v.31 no.5
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    • pp.607-623
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    • 2021
  • This study presents projections of future extreme climate over the Korean Peninsula (KP), using bias-corrected data from multiple regional climate model (RCM) simulations in CORDEX-EA Phase 2 project. In order to confirm difference according to degree of greenhouse gas (GHG) emission, high GHG path of SSP5-8.5 and low GHG path of SSP1-2.6 scenario are used. Under SSP5-8.5 scenario, mean temperature and precipitation over KP are projected to increase by 6.38℃ and 20.56%, respectively, in 2081~2100 years compared to 1995~2014 years. Projected changes in extreme climate suggest that intensity indices of extreme temperatures would increase by 6.41℃ to 8.18℃ and precipitation by 24.75% to 33.74%, being bigger increase than their mean values. Both of frequency indices of the extreme climate and consecutive indices of extreme precipitation are also projected to increase. But the projected changes in extreme indices vary regionally. Under SSP1-2.6 scenario, the extreme climate indices would increase less than SSP5-8.5 scenario. In other words, temperature (precipitation) intensity indices would increase 2.63℃ to 3.12℃ (14.09% to 16.07%). And there is expected to be relationship between mean precipitation and warming, which mean precipitation would increase as warming with bigger relationship in northern KP (4.08% ℃-1) than southern KP (3.53% ℃-1) under SSP5-8.5 scenario. The projected relationship, however, is not significant for extreme precipitation. It seems because of complex characteristics of extreme precipitation from summer monsoon and typhoon over KP.

Predicting the suitable habitat distribution of Conyza sumatrensis under RCP scenarios (RCPs 기후변화 시나리오에 따른 큰망초(Conyza sumatrensis)의 적합 서식지 분포 예측)

  • Myung-Hyun Kim;Soon-Kun Choi;Jaepil Cho;Min-Kyeong Kim;Jinu Eo;So-Jin Yeob;Jeong Hwan Bang
    • Korean Journal of Environmental Biology
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    • v.40 no.1
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    • pp.1-10
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    • 2022
  • Global warming has a major impact on the Earth's precipitation and temperature fluctuations, and significantly affects the habitats and biodiversity of many species. Although the number of alien plants newly introduced in South Korea has recently increased due to the increasing frequency of international exchanges and climate change, studies on how climate change affects the distribution of these alien plants are lacking. This study predicts changes in the distribution of suitable habitats according to RCPs climate change scenarios using the current distribution of the invasive alien plant Conyza sumatrensis and bioclimatic variables. C. sumatrensis has a limited distribution in the southern part of South Korea. Isothermality (bio03), the max temperature of the warmest month (bio05), and the mean temperature of the driest quarter (bio09) were found to influence the distribution of C. sumatrensis. In the future, the suitable habitat for C. sumatrensis is projected to increase under RCP 4.5 and RCP 8.5 climate change scenarios. Changes in the distribution of alien plants can have a significant impact on the survival of native plants and cause ecosystem disturbance. Therefore, studies on changing distribution of invasive species according to climate change scenarios can provide useful information required to plan conservation strategies and restoration plans for various ecosystems.

A Study about the Impact of Atmospheric Environmental Changes by Urban Development on Human Health (도시개발에 따른 대기환경 변화가 건강에 미치는 영향연구)

  • Kim, Jea-Chul;Lee, Chong-Bum;Cheon, Tae-Hun;Jang, Yun-Jung
    • Journal of Environmental Impact Assessment
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    • v.19 no.1
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    • pp.15-28
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    • 2010
  • Because deterioration of air quality and urban heat island directly harm health of citizens, Health Impact Assessment (HIA) and Environmental Impact Assessment (EIA) for urban development projects needs to conduct analysis of their impacts objectively. This study aims to review appropriate methods for assessment of air quality used at each stage of urban development and to investigate prediction and assessment methods of urban heat island. In addition, by evaluating impacts of climate change following supposed urban construction performed in the central area of Korea on public health, it examines usefulness of HIA for urban construction. When urban heat island prediction and HIA method suggested in this study are applied to an imaginary city, they predict urban heat island properly and the impacts of climate changes on public health inside the city could be determined clearly by calculating life-climate index and bio-climate index related with thermal environment from the model.

The Impact of Abrupt Climate Change on the Marine Ecosystem in the East Sea

  • Shin, Im-Chul;Yi, Hi-Il;Chung, Hyo-Sang;Kwon, Won-Tae;Chun, Jong-Hwa;Oh, Hyun-Taek
    • The Korean Journal of Quaternary Research
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    • v.17 no.2
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    • pp.1-7
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    • 2003
  • Environmental changes caused by the abrupt climatic change are one of the important issues in the scientific community. In the East Sea, abrupt climatic shift, called Younger Dryas, is identified. The age of the Younger Dryas cold episode occurred at 11.2 ka. Overall, changes in circulation and bottom water conditions occurred during the Younger Dryas cold episode in the study area. Especially, climatic transition from meltwater spike to the Younger Dryas cold episode is characterized by significant shifts of oxygen isotope values, the coiling ratios of Neogloboquadrina pachyderma, and the planktonic foraminifers abundances. The impact of abrupt climate change on the ecosystem is very significant. In the East Sea, the calcium carbonate secreting organism(foraminifers) is replaced by silicon dioxide secreting organisms(diatom, radiolarian) after the abrupt and severe cold climatic event. Based on the Doctrine of Uniformitarianism, at least climate change for the next 100 years would be severely influence on the marine ecosystem.

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Outlook for consumption of subtropical vegetables and required cultivation area (아열대채소의 소비량과 필요재배면적 전망)

  • Lee, Hong-Jin;Kim, Sung-Yong;Kim, Yun-Sik;Jeon, Sang-Gon
    • Korean Journal of Agricultural Science
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    • v.40 no.4
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    • pp.425-434
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    • 2013
  • Nowadays, the korean peninsula has endured weather changes toward to the subtropical climate. Also demographical structure has changed into multi-cultural society in which many people from subtropical areas have immigrated into Korea. Therefore, consumption and production of subtropical vegetables become important. For the analysis, we choose eight important subtropical crops. EDM (Equilibrium Displacement Model) with many parameters and elasticities is used for the forecast of consumption and required cultivation area. The simulation focuses on the changes of the number of foreign workers and immigrated women in Korea to predict the quantity of consumption and required area in Korea. The results show that we need additional land area about 581~1,065 ha for the cropping subtropical vegetables in Korea. Finally, these required area can be provided by the cities and counties in coast area in Gyeongsangnam-Do, Jeonranam-Do and Jeju-Do. Climate change will be continued in the future. Together with climate change, the change of demographical structure into multi-culture may increase consumption and production of subtropical vegetables. Forecasting of increased consumption and required cultivation area for subtropical vegetables is significant.

A Geochemical Boundary in the East Sea (Sea of Japan): Implications for the Paleoclimatic Record

  • Han, Sang-Joon;Hyun, Sang-Min;Huh, Sik;Chun, Jong-Hwa
    • Ocean and Polar Research
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    • v.24 no.2
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    • pp.167-175
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    • 2002
  • Sediment from six piston cores from the East Sea (Sea of Japan) was analyzed for evidence of paleoceanographic changes and paleoclimatic variation. A distinct geochemical boundary is evident in major element concentrations and organic carbon content of most cores near the 10-ka horizon. This distinctive basal Holocene change is interpreted to be largely the result of changing sediment sources, an interpretation supported by TiO_2/Al_2O_3$ ratios. Organic carbon and carbonate contents also differ significantly between the Holocene and glacial intervals. The C/N ratio of organic matter is greater than 10 during the glacial period, but is less than 10 for the Holocene, suggesting that the influx of terrigenous organic matter was more volumetrically important than marine organic matter during glacial times. The chemical index of weathering (CIW) is higher for the Holocene than the glacial interval, and changes markedly at the basal Holocene geochemical boundary. Silt fractions are higher in the glacial interval, suggesting a strong effect of climate on silt particle transportation: terrigenous aluminosilicates and continental organic carbon transport were higher during glacial times than during the Holocene. Differences in sediment composition between the Holocene and glacial period are interpreted to have been climatically induced.

Spatial Changes in Work Capacity for Occupations Vulnerable to Heat Stress: Potential Regional Impacts From Global Climate Change

  • Kim, Donghyun;Lee, Junbeom
    • Safety and Health at Work
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    • v.11 no.1
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    • pp.1-9
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    • 2020
  • Background: As the impact of climate change intensifies, exposure to heat stress will grow, leading to a loss of work capacity for vulnerable occupations and affecting individual labor decisions. This study estimates the future work capacity under the Representative Concentration Pathways 8.5 scenario and discusses its regional impacts on the occupational structure in the Republic of Korea. Methods: The data utilized for this study constitute the local wet bulb globe temperature from the Korea Meteorological Administration and information from the Korean Working Condition Survey from the Occupational Safety and Health Research Institute of Korea. Using these data, we classify the occupations vulnerable to heat stress and estimate future changes in work capacity at the local scale, considering the occupational structure. We then identify the spatial cluster of diminishing work capacity using exploratory spatial data analysis. Results: Our findings indicate that 52 occupations are at risk of heat stress, including machine operators and elementary laborers working in the construction, welding, metal, and mining industries. Moreover, spatial clusters with diminished work capacity appear in southwest Korea. Conclusion: Although previous studies investigated the work capacity associated with heat stress in terms of climatic impact, this study quantifies the local impacts due to the global risk of climate change. The results suggest the need for mainstreaming an adaptation policy related to work capacity in regional development strategies.

Assessment of Future Climate Change Impact on DAM Inflow using SLURP Hydrologic Model and CA-Markov Technique

  • Kim, Seong-Joon;Lim, Hyuk-Jin;Park, Geun-Ae;Park, Min-Ji;Kwon, Hyung-Joong
    • Korean Journal of Remote Sensing
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    • v.24 no.1
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    • pp.25-33
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    • 2008
  • To investigate the hydrologic impacts of climate changes on dam inflow for Soyanggangdam watershed $(2694.4km^2)$ of northeastern South Korea, SLURP (Semi-distributed Land Use-based Runoff Process) model and the climate change results of CCCma CGCM2 based on SRES A2 and B2 were adopted. By the CA-Markov technique, future land use changes were estimated using the three land cover maps (1985, 1990, 2000) classified by Landsat TM satellite images. NDVI values for 2050 and 2100 land uses were estimated from the relationship of NDVI-Temperature linear regression derived from the observed data (1998-2002). Before the assessment, the SLURP model was calibrated and verified using 4 years (1998-2001) dam inflow data with the Nash-Sutcliffe efficiencies of 0.61 to 0.77. In case of A2 scenario, the dam inflows of 2050 and 2100 decreased 49.7 % and 25.0 % comparing with the dam inflow of 2000, and in case of B2 scenario, the dam inflows of 2050 and 2100 decreased 45.3 % and 53.0 %, respectively. The results showed that the impact of land use change covered 2.3 % to 4.9 % for the dam inflow change.