• 대한건축학회논문집:계획계
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• 제35권6호
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• pp.27-37
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• 2019

This study focused on the possibility of reducing the cooling load through the change of micro climate in the outdoor space during summer season. This study proposes an efficient planning model by comparing the effects of urban heat island mitigation through wind path planning, outdoor space vegetation, and exterior material change by using the basic model of the street-oriented block housing proposed in the previous research by the same author. As a result, the most effective wind path planning strategy in the street-oriented block housing was the change of the air flow through the mass height adjustment. When the tall building masses were staggered and arranged in a balanced manner, the overall wind environment could be improved. The greater the height difference between low and high masses, the better the air flow was shown. It was also important to arrange the building masses so that the inlet of the main wind was open and to allow the external space to connect to the adjacent block to create a continuous flow. The change of outdoor space vegetation and flooring, and the formation of wind paths through the opening of lower part also showed the effect of heat island reduction. In addition, the change of PMV in summer was the biggest influence of shadow by tall building mass. Attention should be paid to the fact that high-albedo exterior materials are adversely affected by multiple reflections in dense street-oriented block housing. The use of albedo of the exterior material showed that it is necessary to pay attention to apply in the high density block housing. This is attributed to the rise of the temperature due to the absorption of energy into the low-albedo flooring, where the high-albedo exterior causes multiple reflections.

• 한국산림과학회지
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• 제109권4호
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• pp.521-531
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• 2020

이 연구의 목적은 임업과 목재산업이 전체 경제에 미치는 영향 그리고 산업의 연관관계를 분석하는 데 있다. 이를 위해 한국은행의 2015년 산업연관표를 이용하여 임업과 목재산업 중심으로 재분류하고 경제적 파급효과와 다른 산업에 미치는 영향을 분석하였다. 생산유발효과는 종이제품 생산업, 제재업, 영림업에서 상대적으로 높게 나타났고, 다른 목재산업의 생산유발효과는 크지 않았다. 부가가치유발효과는 영림과 원목생산에서 높게 나타났다. 그리고 목재산업에서 후방연쇄효과보다 전방연쇄효과가 높게 나타나 경제 전체를 유지하는 데 중요한 것으로 나타났다. 다른 산업에 미치는 파급효과를 분석한 결과를 보면 목재산업의 생산증가가 임업에 미치는 파급효과가 크지 않은 것으로 나타났다. 목재산업과 임업은 산림생태계관리와 기후변화 대응에서 중요한 역할을 하므로 이들의 연관성을 높이는 것은 산림정책에서 중요한 정책과제이다.

• Journal of Ecology and Environment
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• 제46권3호
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• pp.250-258
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• 2022

Background: To assess the carbon sequestration capacity and net ecosystem productivity (NEP) of Quercus glauca forests, we analyzed the net primary productivity (NPP), carbon storage, and carbon emission of soil in a Q. glauca forest on Jeju Island (South Korea) from 2016 to 2018. Results: The average carbon stock in the above- and below-ground plant biomass was 223.7 Mg C ha^-1, while the average amount of organic carbon fixed by photosynthesis was 9.8 Mg C ha^-1 yr^-1, and the average NPP was 9.6 Mg C ha^-1 yr^-1. Stems and branches contributed to the majority of the above- and below-ground standing biomass and NPP. The average heterotrophic carbon emission from the soil was 8.7 Mg C ha^-1 yr^-1, while the average NEP was 1.1 Mg C ha^-1 yr^-1. Although the carbon stock, carbon absorption, and soil respiration values were higher than those reported in other oak forests in the world, the NEP was similar or lower. Conclusions: These results indicator that Q. glauca forests perform the role of a large carbon sink through the CO₂ absorption in the plants in terms of carbon balance. And it is judged to be helpful as data for assessment of carbon storage and flux in the forests and mitigation of elevated CO₂ in the atmosphere.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.498-498
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• 2023

정부와 지자체는 기후변화로 인한 홍수 피해를 저감하고자 내수배제 용량 증대, 건전한 물환경 조성 등 다양한 방향의 정책들을 제시하고 있다. 각 지자체 별로 다양한 홍수 대응 정책들을 반영하고 있지만, 2022년 집중호우에 의한 도심지역 침수 피해 사례와 같이 기후변화로 인하여 증가된 홍수량에 대한 적절한 대비를 못하고 있다. 따라서 지자체는 현재의 홍수 대응 정책들과 더불어 추가적인 홍수 대응 정책을 시행하여야 하며, 지속가능한 개발을 고려한 유역의 건전한 물순환을 유지해야 한다. 본 연구에서는 토지피복 등 유역의 특성을 고려하여 실행 가능한 홍수 정책들의 대응 효과를 분석하고, 기후변화 시나리오를 반영한 미래 빈도분석 결과를 반영하여 최적의 홍수 대응 정책 대안을 제시하고자 한다. 연구에서 선정한 홍수 대응 정책은 우수관거 용량을 증대시키는 관거 교체 정책, 지속가능한 저영향개발 기법을 적용한 투수성 포장과 옥상녹화 정책을 선정하였다. 미래 강우 시나리오는 3개의 CMIP6 GCM모형(ACCESS-CM2, CanESM5, GFDL-ESM4)과 2개의 SSP-RCP 시나리오(SSP1-26, SSP5-85)를 사용하였다. 홍수 저감 효과는 도시유출해석모형인 SWMM 모형으로 분석하였다. 또한, 정책 이행에 발생하는 공사와 운영 비용을 산정하여 경제적 편익 분석을 실시하였다. 분석 결과, 투수성 포장과 우수관거 용량 확대 정책을 반영하는 정책 시나리오가 가장 경제적인 홍수 저감 효과를 가져오는 것으로 분석되었다. 본 연구의 정책별 경제적 비용과 홍수 저감 효과 분석은 기후변화에 대비한 도시유역의 홍수 대응 정책을 평가하고 우선순위를 선정하는데 있어 기여 할 수 있을 것으로 기대된다.

• 농촌계획
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• 제28권4호
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• pp.93-104
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• 2022

Agriculture is one of the most vulnerable sector to droughts, and drought damage on the agriculture sector could have effects on other sector. Droughts have different characteristics compared to other extreme events, which means more sophisticated methods considering the characteristics of droughts are required when measuring their damage. The purpose of this study is to analyze the damage of droughts based on limited computational general equilibrium model. To be specific, we constructed a CGE model focusing on the agriculture sector in Korea. Also, to limit changes in land use and labor, we limited them, and assume droughts only have effects on productivity of value-added. Lastly, we simulate drought effects on rice production in Korea based on several climate scenarios and GCM to identify the economic effects of droughts. The results show that 1) the cumulated damage of droughts during 2021~2040 is higher than other periods (2040~2061, 2081~2100), 2) the correlation between the damage of droughts and SSP scenarios is insignificant. This result implies the necessity of the effective drought risk management to prevent future droughts effects, irrespective of mitigation policies. 3) Due to increases in rice price, GDP of rice sector is increased. However, GDP of the other sector and consumer welfare are decreased. This result show that indirect effects of droughts would be more important when measuring drought effects on agriculture sector.

• 한국농공학회논문집
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• 제65권3호
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• pp.57-67
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• 2023

A flash drought is a rapid-onset drought that develops over a short period of time as weather and environmental factors change rapidly, unlike general droughts, due to meteorological abnormalities. Abnormally high evapotranspiration rates and rapid declines in soil moisture increase vegetation stress. In addition, crop yields may decrease due to flash droughts during crop growth and may damage agricultural and economic ecosystems. In this study, Flash Drought Intensity Index (FDII) based on soil moisture data from Gravity Recovery Climate Experiment (GRACE) was used to analyze flash drought. FDII, which is calculated using soil moisture percentile, is expressed by multiplying two factors: the rate of intensification and the drought severity. FDII was developed for domestic flash drought events from 2014 to 2018. The flash drought that occurred in 2018, Chungcheongbuk-do showed the highest FDII. FDII was higher in heat wave flash drought than in precipitation deficit flash drought. The results of this study show that FDII is reliable flash drought analysis tool and can be applied to quantitatively analyze the characteristics of flash drought in South Korea.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2019년도 정기학술대회 발표논문집
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• pp.134-134
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• 2019

Utilization of organic waste as a renewable energy source is promising for sustainability and mitigation of climate change. Pyrolysis converts organic waste to gas, oil, and biochar by incomplete biomass combustion. Biochar is widely used as a soil conditioner and adsorbent. Biochar adsorbs/desorbs metals and ions depending on the soil environment and condition to act as a nutrient buffer in soils. Biochar is also regarded as a carbon storage by fixation of organic carbon. Phosphorus (P) and nitrogen (N) are strictly controlled in many wastewater treatment plants because it causes eutrophication in water bodies. P and N is removed by biological and chemical methods in wastewater treatment plants and transferred to sludge for disposal. On the other hand, P is an irreplaceable essential element for all living organisms and its resource (phosphate rock) is estimated about 100 years of economical mining. Therefore, P and N recovery from waste and wastewater is a critical issue for sustainable human society. For the purpose, intensive researches have been carried out to remove and recover P and N from waste and wastewater. Previous studies have shown that biochars can adsorb and desorbed phosphates implying that biochars could be a complementary fertilizer. However, most of the conventional biochar have limited capacity to adsorb phosphates and nitrate. Recent studies have focused on biochar impregnated with metal salts to improve phosphates and nitrate adsorption by synthesizing biochars with novel structures and surface properties. Metal salts and metal oxides have been used for the surface modification of biochars. If P removal is the only concern, P adsorption kinetics and capacity are the only important factors. If both of P and N removal and the application of recovery are concerned, however, P and N desorption characteristics and bioavailability are also critical factors to be considered. Most of the researches on impregnated biochars have focused on P removal efficiency and kinetics. In this study, coffee waste is thermally treated to produce biochar and it was impregnated with Mg/Al to enhance phosphates and nitrate adsorption/desorption and P bioavailability to increase its value as a fertilizer. Kinetics of phosphates and nitrate adsorption/desorption and bioavailability analysis were carried out to estimate its potential as a P and N removal adsorbent in wasewater and a fertilizer in soil.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2021년도 추계학술대회
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• pp.132-133
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• 2021

In recent years, energy harvesting from natural sources and waste heat has been attracting more attention from researchers in response to ever-growing energy demands, high energy prices, and climate-change-mitigation purposes. It is also an important step towards future sustainable energy usages. In thermal dynamic cycles, expanders are playing as the most important equipment for waste heat recovery and energy harvesting as well. As a kind of expander, the bladeless turbine has a promising future and more widely using owning its advantages on relatively long life, good off-design performance, easy operation cleaning and maintenance, a simple structure, no blade corrosion, and low manufacturing costs. There are numerous studies about using the Tesla Turbine as a key technology for energy harvesting in a wide range of applications and conditions. They are presented to help identify technologies that have sufficient potential for applicating to our life and marine industrial engineering. This review paper, initially, presents an overview of current studies both theoretical and experimental of Tesla Turbine usage for waste heat recovery alongside its challenges and investigation on the effect of its configuration, working fluid selection as well. To conclude, future perspectives besides possible ways of transforming waste heat energy to electricity or work, which leads to circular energy, are discussed. The ambition of this paper is to act as a first-hand reference, through the well-defined possible directions, to the young researchers and senior scientists.

• 농업과학연구
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• 제50권4호
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• pp.967-976
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• 2023

Biochar is emerging as a promising substance for achieving carbon neutrality and climate change mitigation. It can absorb several nutrients via ion bonding on its surface functional groups, resulting in slow dissociation of the bonds. Biochar, like organic fertilizers, contributes to sustainable nutrient management. The purpose of this study was to investigate the effects of nutrient-coated biochar amendments on leafy vegetables production and soil fertility. The nutrient-coated biochar was produced by soaking rice husk biochar in a nutrient solution containing nitrogen (N), phosphorus, and potassium for 24 hours. Nutrient-coated biochar and organic fertilizers were applied to soil at a rate of 120 kg·N·ha^-1. The growth components of the leafy vegetables showed that nutrient-coated biochar led to the highest fresh weight (FW) of both lettuce and kale (i.e., 146.67 and 93.54 g·plant^-1 FW, respectively). As a result, nutrient-coated biochar amendments led to superior yield compared to the control treatment and organic fertilization. The elemental composition of leafy vegetables revealed that soil amended with nutrient-coated biochar resulted in higher nutrient contents, which was attributed to the high nutrient contents supplied by the rice husk biochar. Soil amendment with nutrient-coated biochar positively enhanced the soil fertility compared to amendment with organic fertilizer. Therefore, nutrient-coated biochar is a promising substance for enhancing agronomic performance of leafy vegetables and improving soil fertility.

• 한국환경복원기술학회지
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• 제27권1호
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• pp.45-54
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• 2024

This study developed a model to evaluate the co-benefits and trade-off effects between biodiversity and carbon storage capacity based on the implementation locations of nature-based solutions. The model aims to propose optimal implementation locations by using the conceptual idea of edge effects for carbon storage and connectivity for biodiversity. The co-benefits were considered by simultaneously taking into account two effects rather than a single effect. Trade-off effects were observed among optimal plans through a comparison of benefits. The NSGA-II multi-objective optimization algorithm was utilized, confirming the identification of Pareto-optimal solutions. The implementation patterns of Pareto-optimal solutions for green areas were examined. This study holds significance in proposing optimal locations by evaluating various co-benefits and trade-off effects of nature-based solutions. By advancing models based on this evaluation framework, it is anticipated that the assessment of co-benefits and trade-off effects among various benefits of nature-based solutions, such as climate change mitigation, enhancement of biodiversity, and provision of ecosystem services, can be accomplished.