• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.22 no.6
• /
• pp.115-124
• /
• 2019

In a climate change environment where heat damage and drought occur during a rainy season such as in 2018, a vegetation-based LID system that enables disaster prevention as well as environment improvement is suggested in lieu of an installation-type LID system that is limited to the prevention of floods. However, the quantification of its performance as against construction cost is limited. This study aims to present an experiment environment and evaluation method on quantitative performance, which is required in order to disseminate the vegetation-based LID system. To this end, a 3^rd quartile huff time distribution mass curve was generated for 20-year frequency, 60-minute probable rainfall of 68mm/hr in Cheonan, and effluent was analyzed by recreating artificial rainfall. In order to assess the reliability of the rainfall event simulator, 10 repeat tests were conducted at one-minute intervals for 20 minutes with minimum rainfall intensity of 22.29mm/hr and the maximum rainfall intensity of 140.69mm/hr from the calculated probable rainfall. Effective rainfall as against influent flow was 21.83mm/hr (sd=0.17~1.36, n=20) on average at the minimum rainfall intensity and 142.27mm/hr (sd=1.02~3.25, n=20) on average at the maximum rainfall intensity. In artificial rainfall recreation experiments repeated for three times, the most frequent quartile was found to be the third quartile, which is around 40 minutes after beginning the experiment. The peak flow was observed 70 minutes after beginning the experiment in the experiment zone and after 50 minutes in the control zone. While the control zone recorded the maximum runoff intensity of 2.26mm/min(sd=0.25) 50 minutes after beginning the experiment, the experiment zone recorded the maximum runoff intensity of 0.77mm/min (sd=0.15) 70 minutes after beginning the experiment, which is 20 minutes later than the control zone. Also, the maximum runoff intensity of the experiment zone was 79.6% lower than that of the control zone, which confirmed that vegetation unit-type LID system had rainfall runoff reduction and delay effects. Based on the above findings, the reliability of a lab-level rainfall simulator for monitoring the vegetation-based LID system was reviewed, and maximum runoff intensity reduction and runoff time delay were confirmed. As a result, the study presented a performance evaluation method that can be applied to the pre-design of the vegetation-based LID system for rainfall events on a location before construction.

• Membrane Journal
• /
• v.28 no.2
• /
• pp.113-120
• /
• 2018

Global warming due to indiscriminate carbon dioxide emissions has a profound impact on human life by causing abnormal climate change and ecosystem destruction. As a way to reduce carbon dioxide emissions, in this study, we presented a polymeric membrane prepared by blending a self-crosslinkable P(GMA-g-PPG)-co-POEM (SP) copolymer and commercial polymer polyvinylpyrrolidone (PVP). As the content of PVP increased, it was observed that the gas permeance decreased and $CO_2/N_2$ selectivity increased. At 30 wt% PVP content, the $CO_2$ permeance of the membrane decreased from 72.9 GPU of pure SP polymer to 12.6 GPU, while $CO_2/N_2$ selectivity improved by 79% from 28.1 to 50.4. It results from the hydrogen bonding between the SP copolymer and PVP, leading to more compact structure of the polymer chains, which was confirmed by FT-IR, TGA, XRD and SEM analysis. Therefore, we suggest that the permeance and selectivity of the membranes can be easily adjusted as desired by controlling the PVP content in the SP/PVP polymer blend.

• Journal of Environmental Science International
• /
• v.18 no.6
• /
• pp.655-665
• /
• 2009

This study aims to identify the impacts of air quality in the Korean Peninsula according to the China's environmental policies in preparation of the Beijing 2008 Olympic Games. The measurement of emission variations in China, aircraft measurement, and modelling were carried out. The reduction measures in Beijing, China and its emission changes resulted in $30{\sim}65%$ in decrease out of the total emissions within the Beijing region, whereas when it comes to the whole nation of China, the reduction rate was about $4{\sim}9%$. Comparing the concentration of the air pollutants in Seoul and Ganghwa in August 2008 during around the period of Beijing Olympic Games with one in $2004{\sim}2007$ showed that the $SO_2$ concentrations in the past was above 5ppb, while the concentration in the 2008 olympic period was 4ppb and below. The NOx at the Seokmori site in Ganghwa tended to be lower in concentration in 2008 than in between $2004{\sim}2007$. As for $O_3$ and $PM_{2.5}$, the concentration tended to be rather low since August 11. The air current track that showed during the period of aircraft measurement presented to be flowed into Korea through the Northeast part of China and the coast of Bohai Bay, while the concentrations of $SO_2$. NOx, and $O_3$ over the west sea on August 20 and 24 were 0.54 (0.28ppb), 0.86 (1.84ppb), and 54.0 (41.5ppb) respectively, similar or lower than the ones measured in the past in the similar current patterns. The modelling result showed similar patterns to the data of aircraft measurement, in particular in $SO_2$. Overall, the reduction measures in Beijing, China affected directly and indirectly the air quality in the Korean peninsular, but the impact was not significant as it was momentary and limited to the intended area.

• Environmental and Resource Economics Review
• /
• v.21 no.4
• /
• pp.809-850
• /
• 2012

A linkage of emissions trading schemes among Korea, China and Japan demonstrates overall increase in gross domestic product (GDP). However, it also demonstrates reductions in household consumption, and the impact of integration could be very unbalanced between the countries. In particular, the reductions in domestic marginal costs are high in both Korea and Japan. Therefore, household consumptions in the two countries decrease despite increases in GDP because Korea and Japan will be purchasers of emissions rights. China, on the other hand, will experience the opposite. The unbalanced impacts on real household consumptions are intensified when emission credits are allocated via paid auctions instead of free allocation. This was demonstrated to be the case because the circumstances of three countries are intensified when using a paid emissions credit allocation scheme, and their differences could potentially hinder the cooperation between the three countries. Under the free allocation scheme, the emission trading schemes' unbalanced impacts on consumption could be mitigated, but unavoidable negative impacts of free allocation schemes are also serious. Based on the analysis results, Korea, China, and Japan will individually face complicated impacts if their carbon markets are integrated. Although the GDP of three countries will increase as a result of carbon market integration, the benefits of integration will surely be unbalanced, and the three countries will experience negative impacts in terms of actual consumption or employment. In particular, increases in income and consumption, reductions in employment, and energy dependence by credit purchasers (Japan and Korea) and production reduction and possibility of offshoring faced by revenue producing countries (China) could serve as a barrier to carbon market integration. To maximize the positive influences of carbon market integration while reducing the risks of negative side effects, the development and application of complimentary policy tools, such as import duties or discounts for emissions credits, are required.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.26 no.5
• /
• pp.506-513
• /
• 2020

Due to climate change, there is an increasing risk of complex (hybrid) disasters, comprising rising sea-levels, typhoons, and torrential rains. This study focuses on Marine City, Busan, a new residential city built on a former landfill site in Suyeong Bay, which recently suffered massive flood damage following a combination of typhoons, storm surges, and wave overtopping and run-up. Preparations for similar complex disasters in future will depend on risk impact assessment and prioritization to establish appropriate countermeasures. A framework was first developed for this study, followed by the collection of data on flood prediction and socioeconomic risk factors. Five socioeconomic risk factors were identified: (1) population density, (2) basement accommodation, (3) building density and design, (4) design of sidewalks, and (5) design of roads. For each factor, absolute criteria were determined with which to assess their level of risk, while expert surveys were consulted to weight each factor. The results were classified into four levels and the risk level was calculated according to the sea-level rise predictions for the year 2100 and a 100-year return period for storm surge and rainfall: Attention 43 %, Caution 24 %, Alert 21 %, and Danger 11 %. Finally, each level, indicated by a different color, was depicted on a complex disaster risk map.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.31 no.1D
• /
• pp.111-117
• /
• 2011

In the wake of increased concerns on reduction of greenhouse emission which started with United Nation's Framework Convention on Climate Change (UNFCCC) and Kyoto protocol, Korean government is making various efforts under the represented slogan "Low Carbon, Green Growth". Therefore, it is inevitable that construction industry also follow the Korea government's slogan and the international trend in environmental problems. This study identified several main construction materials and equipments of civil construction projects and suggested a environmental cost estimation method and related estimation standards (Public and private owners are distinguished). A case analysis of a real road construction project is also performed and characteristics according to the owner type is compared. This study analyzed the environmental impact to total construction cost variations. In the result, public owner required 11~16% of extra budget and private owner required 19~22% of extra costs. This study is limited in consideration of environmental factors and carbon trading prices.

• Atmosphere
• /
• v.26 no.3
• /
• pp.357-372
• /
• 2016

Northeast Asian regions have recently become the main source of anthropogenic and natural aerosols. Measurement of aerosols on the sea in these regions have been rarely conducted since the experimental campaigns such as ACE-ASIA (Asian Pacific Regional Aerosol Characterization Experiment) in 2001. Research vessel observations of aerosol mass and chemical composition were performed on the Yellow and south sea around the Korean peninsula. The ship measurements showed six representative cases such as aerosol event and non-event cases during the study periods. On non-event cases, the anthropogenic chemical and natural soil composition on the Yellow sea were greater than those on the south sea. On aerosol event cases such as haze, haze with dust, and dust, the measured mass concentrations of anthropogenic chemical and element compositions were clearly changed by the events. In particular, methanesulfonate ($MSA^-$, $CH_3SO_3^-$), a main component of natural oceanic aerosol important for sulfur circulation on Earth, was first observed by the vessel in Korea, and its concentration on the Yellow sea was three times that on the south sea during the study period. Sea salt concentration important to chemical composition on the sea is related to wind speed. Coefficients of determination ($R^2$) between wind speed and sea salt concentration were 0.68 in $PM_{10}$ and 0.82 in $PM_{2.5}$. Maximum wave height was not found to be correlated to the sea salt concentration. When sea-salt comes into contact with pollutants, the total sea-salt mass is reduced, i.e., a loss of $Cl^-$ concentration from NaCl, the main chemical composing sea salt, is estimated by reaction with $HNO_3$(gas) and $H_2SO_4$(gas). The $Cl^-$ concentration loss by $SO_4^{2-}$ and $NO_3^-$ more easily increased for $PM_{10}$ compared to $PM_{2.5}$. The results of this study will be applied to verifying a dust-haze forecasting model. In addition, continued vessel measurements of aerosol data will become important to research for climate change studies in the future.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.289-289
• /
• 2017

The climate change impact has facilitated double cropping system on maize production in Korea. The objectives of this study were to investigate the chemical composition changes according to the sowing dates on double cropping in 8 dent type, 2 intermediate type, and 4 semiflint type of Korean maize (Zea mays L.) hybrids and evaluate its antioxidant characteristics. Fourteen maize hybrids were sown on April 5 and July 5 of 2015. The average crude protein contents in dent and semiflint type maize sown on April 5 were higher than those sown on July 5 (p<0.05). There was no significant difference in average of total amino acid contents in all types of maize according to the sowing dates. Major amino acid in maize hybrids were glutamic acid followed by proline, alanine, and aspartic acid, which has no significant difference according to the sowing dates. The average crude fat contents in semiflint and intermediate type maize sown on April 5 were higher than those sown on July 5 (p<0.05). The average composition of saturated fatty acid in dent type maize sown on April 5 was higher than those sown on July 5. However, the average unsaturated fatty acid composition showed the opposite result (p<0.05). Fatty acids were mainly composed of linoleic acid (C18:2) and oleic acid (C18:1) in maize hybrids. The average oleic acid percentage of dent and semiflint type maize sown on April 5 were higher than those sown on July 5, while the average linoleic acid was lower. The average amylose content of all types of maize sown on April 5 was higher than those sown on July 5. On the other hands, the average carotenoid contents had the opposite result (p<0.05). There were no significant differences in total average of polyphenol contents and DPPH and ABTS radical scavenging activities in all types of maize based on the sowing date. Total polyphenol contents had positive correlation with DPPH (r=0.33, p<0.01) and ABTS (r=0.50, p<0.0001) radical scavenging activities. In conclusion, the kernel composition affects maize quality. These data are useful for maize breeding program and cultivation and food processing industry.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.8
• /
• pp.502-507
• /
• 2016

The transition from a carbon economy based on fossil fuels to a hydrogen economy is necessary to ensure energy security and to combat climate change. In order to pursue the transition to a hydrogen economy while achieving sustainable economic growth, a preliminary study into the establishment of the necessary infrastructure for the future hydrogen economy needs to be carried out. This study addresses the economic and environmental interactions in a dynamic computable general equilibrium (CGE) model focusing on the economic effects of the introduction of renewable energy into the Korean energy system. Firstly, the introduction of hydrogen results in an increase in the investment in hydrogen production and the reduction of the production cost, ultimately leading to GDP growth. Secondly, the mandatory introduction of renewable energy and associated government subsidies bring about a reduction in total demand. Additionally, the mandatory introduction of hydrogen energy into the power sector helps to reduce CO2 emissions through the transition from a carbon economy-based on fossil energy to a hydrogen economy. This means that hydrogen energy needs to come from non-fossil fuel sources in order for greenhouse gases to be effectively reduced. Therefore, it seems necessary for policy support to be strengthened substantially and for additional studies to be conducted into the production of hydrogen energy from renewable sources.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.9
• /
• pp.238-250
• /
• 2020

This study investigated the long-term measures to minimize flood damage in the event of flooding in urban areas. The relationship between urban spatial factors and the impact of flood damage was analyzed, focusing on non-structural measures. The urban spatial factors were categorized into three parts: open space, disaster prevention facilities, and urbanization sectors. Multiple regression analysis was used to investigate how urban spatial factors influence flood damage. As a result of the analysis, the crucial factors, such as the reduced green areas and parks included in the open space sectors, resulted in an increased flood damage potential. The posterior factors, such as the population density and GRDP included in the urbanization sector concurrently led to an increase in the flood damage potential. Therefore, to better adapt to climate change, it is necessary to establish urban spatial plans strategically, such as green areas and parks. Meanwhile, the population density and GRDP are also the main factors causing flood damage. Therefore, when used appropriately in terms of resilience, it will serve as adaptations and recovery.