KJCKorea
Journal Central

PM2.5, a type of fine particulate matter, poses serious health risks. Existing pollution management policies and research have generally focused on high-concentration areas. However, this approach has limitations as it does not adequately account for regional characteristics and varying levels of vulnerability, leading to an incomplete reflection of actual risks in specific areas. This study analyzed 229 administrative districts to develop a vulnerability index by comprehensively evaluating PM2.5 exposure, sensitivity, and adaptive capacity. Using data from 2019, the index was calculated through normalization and entropy weighting methods, and spatial patterns of PM2.5 vulnerability were examined through LISA and K-means clustering analysis. The findings reveal that the distribution of PM2.5-vulnerable areas shows distinct patterns within urban settings, which were classified into four distinct types, each characterized by different urban features. This suggests a need for region-specific dust reduction policies. This study contributes to a better understanding of the spatial patterns of PM2.5 vulnerability and aims to support the development of more effective policy approaches.

Greenhouse gas(GHG) emissions are a major cause of global warming and climate change, and are currently emerging as serious environmental problems worldwide. Among them, glass bottles do not decompose naturally, and a lot of resources and energy are input into the production and processing processes, so recycling of glass bottles is important in terms of resource conservation, minimizing environmental pollution, and reducing GHG. Therefore, this study created a material flow diagram of glass bottles using related statistical data such as domestic glass bottle production and processing volume. In addition, the US EPA WARM model, Prognos calculation method, and Christensen's calculation method were used to estimate the greenhouse gas reduction amount of glass bottles. As a result of the study, out of about 490,000 tons of waste glass bottles discharged as municipal waste, about 300,000 tons (61.2%) were recycled, and the rest were incinerated (22.1%) and landfilled (17.3%). As of 2022, it is estimated that approximately 73,399 tons CO2eq/yr will be reduced when applying the US EPA WARM model, approximately 52,847 tons CO2eq/yr when applying the Prgonos calculation method, and approximately 135,201 tons CO2eq/yr when applying the Christensen's calculation method. Further research is warranted that the methodology and GHG saving emission factors by reflecting glass recycling conditions and processes in Korea should be developed to reduce uncertainty of the results.

Domestic multipurpose dams are operated to secure reservoir capacity during the summer rainy season, supplying domestic water and maintaining environmental flow in downstream rivers during low-flow periods. This operational approach affects the water quality of downstream rivers. The aim of this study is to evaluate the impact of monthly planned discharge from Youngju Dam on the downstream tributaries, NaeseongCheon and the main stream of the Nakdong River. To achieve this, hydrodynamic and water quality modeling was conducted using the CE-QUAL-W2 model to simulate travel times and changes in water quality parameters. The Time Lagged Cross Correlation (TLCC) method was adapted to analyze the correlation between water quality at Youngju Dam and representative points in the downstream NaeseongCheon and Nakdong River, taking into account the travel time of the dam discharge. The analysis revealed a significant water quality correlation between the discharge from Youngju Dam and the NaeseongCheon monitoring point (Point 5), with correlation coefficients ranging from 0.382 to 0.777. However, the correlation coefficients for water quality between Youngju Dam and the main stream of the Nakdong River ranged from -0.528 to 0.317, indicating either a very weak or negative correlation. This suggests that there is no significant correlation between the water quality of Youngju Dam and the Nakdong River main stream. The findings indicate that the main objective of constructing Youngju Dam to improve the water quality of the Nakdong River main stream may not have substantial practical effectiveness. Therefore, it is essential to review the dam’s operational plans with a focus on improving the water quality of NaeseongCheon, which is directly affected by the dam, and to conduct further research in this area.