The extreme weather conditions negatively affect the traffic flow performance, and the change of traffic systems has significant impacts on the air pollutant emission. This study identifies the correlation between rainfall, traffic volume, travel speed and air pollution concentration (NO2 and PM10) in Seoul. We employed a path analysis using rainfall data from Korea Meteorological Administration and Seoul’s air quality and traffic monitoring data in July and August on 2014. It is found that the occurrence of rainfall decreases NO2 and PM10 concentration due to the higher washing effect, while rainfall increases NO2 and PM10 concentration via the changes in traffic volume and traffic speed. The analysis of the rainfall intensity reveals that the rainfall increases NO2 concentration due to the traffic volume increase and the traffic speed reduction if an hourly rainfall is more than 5mm. It is to note that the current model succeeds in identifying the relationship between weather conditions, traffic flow performance and air pollution in a unified and consistent framework, which can be used for better predicting the changes in air pollution concentration.

The Government had devised legislation of Special Act and drew up guidelines for improving air quality in Seoul Metropolitan area. In 2007 local government of Seoul, Incheon and Gyeonggi conducted the results of application policy by reduced air pollutants emission for the first time. Although there was reduction of air pollutant emission in each local government, it was ineffective as expected using air pollution monitoring database. Therefore we worked out a way to prepare modeling input data using the results of enforcement plan. And we simulated surface NO_2 and PM10 before and after decrease in air pollutants emission and examine reduction effects of air pollution according to enforcement regulation except other influence, by using MM5-SMOKE-CMAQ system. Each local government calculated the amount of emission reduction under application policy, and we developed to prepare input data so as to apply to SMOKE system using emission reduction of enforcement plan. Distribution factor of emission reduction were classified into detailed source and fuel codes using code mapping method in order to allocate the decreased emission. The code mapping method also included a way to allocate spatial distribution by CAPSS distribution. According to predicted result using the reduction of NOx emission, NO_2 concentration was decreased from 19.1 ppb to 18.0 ppb in Seoul. In Gyeonggi and Incheon NO_2 concentrations were down to 0.65 ppb and 0.68 ppb after application of enforcement plan. PM10 concentration was reduced from 18.2 ㎍/㎥ to 17.5 ㎍/㎥ in Seoul. In Gyeonggi PM10 concentration was down to 0.51 ㎍/㎥ and in Incheon PM10 concentration was decreased about 0.47 ㎍/㎥ which was the lower concentration than any other cities.

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 30~65% 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 4~9%. 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 2004~2007 showed that the SO2 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 2004~2007. As for O3 and PM2.5, 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 SO2, NOx, and O3 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 SO2. 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.

In order to study the degree of improved air quality as an outcome of the action plan of Atmospheric Environment Improvement in Gimhae, Gyeongnam Province, we investigated the status and trends of air pollutant before and after the plan. Nitrogen dioxide and ozone, both classified as hazardous substances, were closely monitored with particular attention. The level of sulfur dioxide, nitrogen dioxide, fine particles and ozone (but for carbon monoxide) was decreased after the plan was implemented. The number of days on which ozone exceeded the National Ambient Air Quality Standard has decreased, but the level was still often exceeded. The level of nitrogen dioxide did not surpass until the 2006 standard, but when the revised 2007 standard was implemented, it exceeded 80% of some standards. The yearly level of ozone has decreased since the plan was introduced. The concentration of nitrogen dioxide, however, has reduced in high order area while increased in low order area.

Gwangyang Bay is often severely confronted by photochemical pollutants due to its location and dense emissions. It is located in a basin on the south coast of the Korean peninsula and is crossed by a remarkable cluster of hills and mountains of a small horizontal scale that forms a channel. Clearly, the air flow field has a great influence on the dispersion of air pollutants. The characteristics of the wind flow patterns have an important effect on the dispersion of pollutants emitted. In these situations, the distribution of the ozone concentration is extremely complicated because of the superposition of circulations of the air flow fields, especially in complex coastal region. In this study, we examined the distribution of the high level ozone on Gwangyang Bay particularly during the episode day (for 5 years). Among these days, A high level ozone was induced by the development of a sea/land breeze local circulation system, as well as by an anabatic/catabatic flow from the mountains and valley with weakening of the synoptic wind. High level ozone distribution pattern(6 types) on Gwangyang bay is analyzed and the comparison of each pattern reveals substantial localized differences in intensity and distribution of ozone concentration from the site coherence and UPA analysis of ozone concentration. The observed VOC concentration had much difference in concentrations and daily variations between Jungdong and Samil.

The objective of this work is the air quality modeling according to the scenarios of emission on complex terrain. The prognostic meteorological fields and air quality field over complex areas of Seoul, Korea are generated by the PSU/NCAR mesoscale model (MM5) and the Third Generation Community Multi-scale Air Quality Modeling System (Models - 3/CMAQ), respectively. The emission source was driven from the Clean Air Policy Support System of the Korea National institute of Environmental Research (CAPSS), which is a 1 km x 1 km grid in South Korea during 2003. In comparison of air quality fields, the simulated averaged PM10, NO2, and O3 concentration on complex terrain in control case were decreased as compared with base case. Particularly PM10 revealed most substantial localized differences by (18 ～ 24 μg/m3). The reduction rate of PM10, NO2, and O3 is respectively 18.88, 13.34 and 4.17%.

Long-term passive diffusive samplers(PDS) have been used to measure NO2 and SO2 concentrations at 21 sampling sites in Daejeon, Korea during the period of January 2000 - December 2002. The spatial distributions of annual NO2 and SO2 concentrations were mapped. Average annual NO2 concentration over the sampling period was 28.5±12.5 ppb, ranging from 1.2 to 81.7 ppb. Average annual SO2 concentration over the sampling period was 7.7±4.8 ppb, ranging from 0.6 to 26.8 ppb. On average, NO2 concentration was approximately 5.8%(1.6 ppb) larger in 2002. SO2 concentration was decreased by 13%(1.1 ppb) during the sampling period. The seasonal variation of NO2 and SO2 concentration was observed with a tendency to be higher in fall and winter. NO2 and SO2 concentrations measured at different site types(patterns of land use) show significant difference. The observed difference in concentration was associated with difference in emissions of NO2 from motor vehicles and SO2 by non-traffic fuel consumption for heating.

With increasing population densities in cities, underground facilities and entertainment locations are proliferating at a rapid pace in efforts to maximize the use of land. The purpose of this study is to evaluate CO concentration level of subway stations having underground platforms in Busan Metropolitan City, from September to November 2000, over seven times. The places of inquiry include Yonsan-dong station, Somyon station, Busan station, Nampo-dong station and Dusil station. The samplings were conducted at three points of each station, i.e. gates, ticket gates, and platforms. The component of CO concentration is the main elements of indoor air quality evaluation. The total concentrations and average concentrations of CO were the higher at the Somyon station. The distribution of CO concentrations at each station, generally was higher at gate than ticket gates and platforms. The I/O ratios(I-platforms, O-gates) were expressed highly than 1 at the Yonsan-dong station, Busan station, Nampo-dong station and were lower than 1 at the others.

In this study, we investigated the site feasibility for the construction of the incineration facilities in Won Ju City. To assess the environmental impact of its construction, we examined the current status of air quality in the selected candidate sites and predicted the extent of air quality change upon its operation through modification of stack type. If the stack height is assumed to be 70 m, the concentrations of SO2 and dioxin in the surrounding area were predicted to increase by 0.05 ppb and 0.09 pg/㎥, respectively. The impact of its operation was assessed and compared among different sites. According to this analysis, more impact was expected from the residential area for the Dan-Gye site than from agricultural areas of the Kwan-Sul and Sa-Je site.

Air quality modeling about coastal urban region such as Pusan shoud be consider shipping source emmited from ships anchoraging and running. It has been proved at our previous studies that the ratios of air pollutants emission amount in coastal area to inland are 12.2% for NO2 and 11.7% for SO2 and the air quality of coastal urban area consierably counts on ships. Also the dispersion pattern of the air pollutants followed local circulation system in this region. Therefore this study has been developed air quality model which can describe the formation, transport, transformation and deposition processes of air pollutants considering shipping source. Currently, restriction for emission amount of ships does not exist, so our study will be useful to set the emission standard and for devising air quality policy in coastal urban region.

Two experiments were conducted to evaluate breathing zone air quality in Taegu, using automatic analyzers for four air quality standards(SO2, NO2, CO, and O3). First, air target compounds were measured for 8 to 12 hours in each of two commercial areas and five residential areas. Second, air target compounds were hourly measured for 24 hours in each of two commercial areas, two residential areas, and an industrial complex area. Based on the first experiment the breathing zone air was more polluted in the commercial area as compared to the residential area, while the second experiment showed that the breathing zone air was polluted rather in the residential area as compared to the commercial area. The second experiment also indicated that there was some variation of breathing zone air concentration with time and measuring sites. Diurnal variation of breathing zone air concentrations was consistent with previous studies which measured at building height. The highest breathing zone air concentration was shown in Seongseo industrial complex area. An unusual finding of this study was that SO2 concentration in the breathing zone air of Bisandong, a typical residential area of Taegu, was higher than that of other residential areas, even higher than that of Seongseo industrial complex area.

When we conduct environmental impact assessment, main contents consist of summary, project outline, environmental conditions, environmental impacts due to the project, mitigation devices, and alternative measures of harmful impact on environment. In this paper, to understand how they really conduct air quality impact assessment and prediction and examine their effectiveness, we considered the provisions and actual case of environmental impact assessment in Korea with that in Japan. As a result, we propose a method of improving air quality impact assessment and prediction, such as reflection of the result in environmental impact assessment, detailed assessment focused on relatively important environmental impact elements, field measurement investigation over four season and seven sucessive days, the uniformity of units, the proper model development to predict environmental concentration and a biennial environmental impact assessment for ex post management.