タイ国チャオプラヤ川流域の水資源管理に及ぼす気候変動の影響

京都大学0048新制・課程博士博士(工学)甲第22760号工博第4759号新制||工||1744(附属図書館)京都大学大学院工学研究科都市環境工学専攻(主査)教授 清水 芳久, 教授 田中 宏明, 教授 米田 稔学位規則第4条第1項該当Doctor of Philosophy (Engineering)Kyoto UniversityDFA

Spatiotemporal impact of COVID-19 on Taiwan air quality in the absence of a lockdown: Influence of urban public transportation use and meteorological conditions

The unprecedented outbreak of COVID-19 significantly improved the atmospheric environment for lockdown-imposed regions; however, scant evidence exists on its impacts on regions without lockdown. A novel research framework is proposed to evaluate the long-term monthly spatiotemporal impact of COVID-19 on Taiwan air quality through different statistical analyses, including geostatistical analysis, change detection analysis and identification of nonattainment pollutant occurrence between the average mean air pollutant concentrations from 2018–2019 and 2020, considering both meteorological and public transportation impacts. Contrary to lockdown-imposed regions, insignificant or worsened air quality conditions were observed at the beginning of COVID-19, but a delayed improvement occurred after April in Taiwan. The annual mean concentrations of PM10, PM2.5, SO2, NO2, CO and O3 in 2020 were reduced by 24%, 18%, 15%, 9.6%, 7.4% and 1.3%, respectively (relative to 2018–2019), and the overall occurrence frequency of nonattainment air pollutants declined by over 30%. Backward stepwise regression models for each air pollutant were successfully constructed utilizing 12 meteorological parameters (R2 > 0.8 except for SO2) to simulate the meteorological normalized business-as-usual concentration. The hybrid single-particle Lagrangian integrated trajectory (HYSPLIT) model simulated the fate of air pollutants (e.g., local emissions or transboundary pollution) for anomalous months. The changes in different public transportation usage volumes (e.g., roadway, railway, air, and waterway) moderately reduced air pollution, particularly CO and NO2. Reduced public transportation use had a more significant impact than meteorology on air quality improvement in Taiwan, highlighting the importance of proper public transportation management for air pollution control and paving a new path for sustainable air quality management even in the absence of a lockdown

Bioethanol Production from Ceratophyllum demersum L. and Carbon Footprint Evaluation

The aim of this research was to find the suitable conditions for bio-ethanol production from Ceratophyllum demersum L., an abundant aquatic plant. The parameters affected to alcohol production were evaluated. Percentage of solid (10, 20, and 30% (w/v)), the amount of yeast (5, 10, and 15% (w/v)), pH value (4, 5, and 6) and temperature (30, 35, and 40°C) were carried out. The results elucidated that the conditions to produce the maximum bio-ethanol from Ceratophyllum demersum L. was applied with 10% (w/v) of solid, 10% (w/v) of yeast, controlled pH value of 6 and temperature of 30°C. The highest yield of bio-ethanol production was reached 2.92 g ethanol/L within 24 h. Moreover, the Carbon Footprint for ethanol production was calculated only from 2 steps of life cycle analysis which were the step of raw material acquisition from macro algae cultivation and manufacturing process from bio-ethanol production. Consequently, the carbon footprint for ethanol production from Ceratophyllum demersum L. was 77.88 kg CO2 equivalent.