The urban expressway is widely used to avoid traffic jams in highly-populated urban areas. However, vehicle exhaust can be easily transported to the neighboring area including residential buildings. In this study, we investigated the transport and penetration of vehicle exhaust into the nearby high-story residential building. Black carbon (BC) and lung deposited surface area (LDSA) concentrations were monitored every 1 min using an aethalometer (AE51, Magee) and a nanoparticle aerosol monitor (AeroTrak 9000, TSI), respectively. For comparison, the measurement was carried out in both the living room and balcony of the apartment from January 18 to January 25, 2016. The CO2 concentration indicated the presence of residents in the living room and transport of vehicle exhaust from the roadway in the balcony. Its diurnal variation showed a significant difference between weekdays and the weekend, implying the different time activity of residents and traffic volume. BC and LDSA concentrations were 1.4±1.5 μg/m3 and 53.9±45.0 μm2/cm3 indoors, and 1.9±1.0 μg/m3, 76.2±34.5 μm2/cm3 outdoors, respectively. The indoor to outdoor concentration ratios range from 0.6 to 0.8, indicating the significant influence of outdoor vehicle exhaust. The highest concentrations of BC and LDSA were observed in the morning rush hours, except for those indoors during the weekend. In particular, the outdoor effect is significant during the morning rush hours. Indoor air quality management is urgently needed for residents living near the urban expressway.
The urban railway system is a convenient public transportation system, as it carries many people without increasing traffic congestion. However, air quality in urban railway environments is worse than ambient air quality due to the internal location of the source of air pollutants and the isolated space. In this paper, characteristics of particulate matter (PM) pollution in urban railway environments are described from the perspective of diurnal variation, chemical composition and source apportionment of PM. PM concentrations in concourse, platform, passenger cabin, and tunnel are summarized through an analysis of 34 journal articles published in Korea and overseas. This information will be helpful in developing effective policies to reduce PM pollution in urban railway environments.
The paper applies CFD numerical simulation technology, selects the typical urban commercial block as the research object, uses PM I 0 which are from automobile exhausted gas as the source of pollution, simulates the spatial density di stribution of the inhalable pa11icle, verifies the accuracy based on the monitoring data and reveals the diffusion rule of atmospheric pollutants in the three dimensional block space. The results show that there is a close relationship between the diffusion effect of the contaminated gas and three dimensional landscape pattern in blocks. At different height levels such as I 0 meters, 30 meters and 50 meters, the decreasing trend of the density of the pollutants and the uniformity of the spatial distribution are quite obvious. The height of the buildings along the streets, the space combination and the shape of the buildings themselves determine the inner smoothness of the streets. In the urban planning, one must fully consider the effect of three dimensional pattern on air pollution in blocks. From the aspects of urban ventilation, open space, height of the horizon line and disheartened space of the bottom, three dimensional landscape pattern of urban blocks should be optimized, which can effectively improve the current situation of severe atmospheric pollution.
지금까지 매미 울음에 영향을 미치는 환경요인에 관한 연구는 많지 않으며 특히 야간에 우는 매미에 대한 이해는 매우 부족한 상황이다. 따라서 본 연구는 도심지 열대야 및 빛 공해가 매미 울음에 영향을 미치는지 밝히는데 그 목적이 있다. 연구대상지는 서울시 서초구 아파트단지와 원주시 치악산국립공원이었다. 연구 대상종은 여름철 우점종 인 참매미와 말매미를 선정하였다. 매미 울음은 7~8월 사이에 아파트단지는 25일간, 치악산은 14일간, 매일 24시간 녹음하였다. 매미 울음에 영향을 미치는 환경요인은 기온, 강수량, 습도, 일조량을 선정하였다. 통계분석은 시간당 울음, 24시간 울음, 야간 울음(21:00~04:00)의 세 가지 항목과 기상요인과의 상관관계를 분석하였다. 분석 결과 첫 번째, 참매미는 아침 여명기에 울음을 시작하고 이른 아침에 울음의 피크를 이루며, 말매미는 오전과 오후에 울음의 피크를 형성하고 저녁 여명기에 울음을 멈추어 두 종간 울음 패턴의 차이가 있었다. 두 번째, 참매미는 말매미가 본격적으로 울기 시작하면 울음 빈도가 낮아져 종간 영향을 미칠 가능성이 높은 것으로 나타났다. 세 번째, 참매미와 말매미 울음과 기상요인과의 상관관계 분석결과, 두 종 모두 기온이 높을수록 많이 울고 비가 오는 날은 적게 우는 경향을 나타내었다. 네 번째, 야간으로 한정해 보았을 때, 말매미는 야간의 온도가 높을 때(24℃~30℃, 평균 27℃) 우는 데 반해, 참매미는 기상요인과는 상관관계를 나타내지 않았다. 그러나 참매미는 조명이 있는 지역에서만 야간에 울고 있어 빛공해가 원인으로 추정되었다.
Ozone precursor emissions and meteorological conditions have large impact on ozone concentrations. In this research, Data referring to an approximately 14-year period (1996~ 2009) are analyzed in order to estimate the trend of the daily maximum hourly value of ozone concentration at national capital region. A Kolmogorov-Zurbenko (KZ) filter is applied to remove the short-term component from the raw time series of ozone and meteorological variables. Meteorological effects are removed from filtered ozone series using multiple linear regression based on meteorological variables. The results show significant differences in local ozone concentrations. Especially, Ulsan area shows continuously increasing trend in ozone concentrations.
Recently, summer high temperature events caused by climate change and urban heat island phenomenon have become a serious social problem around the world. Urban areas have low albedo and huge heat storage, resulting in higher temperatures and longer lasting characteristics. To effectively consider the urban heat island measures, it is important to quantitatively grasp the impact of urban high temperatures on the society. Until now, the study of urban heat island phenomenon had been carried out focusing only on the effects of urban high temperature on human health (such as heat stroke and sleep disturbance). In this study, we focus on the effect of urban heat island phenomenon on air pollution. In particular, the relationship between high temperature phenomena in urban areas during summer and the concentration of photochemical oxidant is investigated. High concentrations of ozone during summer are confirmed to coincide with a day when the causative substances (NO2,VOCs) are high in urban areas during the early morning hours. Further, it is noted that the night urban heat island intensity is large.. Finally, although the concentration of other air pollutants has been decreasing in the long term, the concentration of photochemical oxidant gradually increases in Daegu.
This study was performed to analyze the effects of a water circulation green area plan on non-point source pollution in Gimhae South Korea. A quantitative analysis of Arc-GIS data was conducted by applying a watershed model based on Fortran to investigate the changes to direct runoff and pollution load. Results showed that prior to the implementation of the water circulation green area plan in Gimhae, direct runoff was 444.05 m3/year, total biological oxygen demand (BOD) pollution load was 21,696 kg/year, and total phosphorus (TP) pollution load was 1,743 kg/year. Implementation of the development plan was found to reduce direct runoff by 2.27%, BOD pollution load by 1.16% and TP pollution load by 0.19% annually. The reduction in direct runoff and non-point source pollution were attributed to improvements in the design of impermeable layers within the city.
The purpose of this study was to analyse the runoff characteristics of non-point pollution sources in an urban watershed and determine the effectiveness of newly installed riverwater treatment system to reduce water pollution caused by storm runoff in the urban watershed. The results of this study showed that the levels of BOD5 and suspended solid were highly influenced by first-flush effect and the pollutant load of those two parameters were also very high in the urban watershed. Meanwhile, the effectiveness of riverwater treatment system to reduce the levels of BOD5 and suspended solid was relatively high, but those to reduce the levels of T-N and T-P was low, which needs some additional unit treatment process such as filtration and coagulation. Nonetheless, the riverwater treatment system tested was relatively simple in installation and operation, effective in removing many water pollutants and, most importantly, does not require much space as other treatment systems, so it could be an attractive alternative option to reduce riverwater pollution caused by storm runoff in urban watersheds.
The relationship between urban spatial structures and GHG-AP integrated emissions was investigated by statistically analyzing those from 25 administrative districts of Seoul. Urban spatial structures, of which data were obtained from Seoul statistics yearbook, were classified into five categories of city development, residence, environment, traffic and economy. They were further classified into 10 components of local area, population, number of households, residential area, forest area, park area, registered vehicles, road area, number of businesses and total local taxes. GHG-AP integrated emissions were estimated based on IPCC(intergovernmental panel on climate change) 2006 guidelines, guideline for government greenhouse inventories, EPA AP-42(compilation of air pollutant emission factors) and preliminary studies. The result of statistical analysis indicated that GHG-AP integrated emissions were significantly correlated with urban spatial structures. The correlation analysis results showed that registered vehicles for GHG (r=0.803, p<0.01), forest area for AP (r=0.996, p<0.01), and park area for AP (r=0.889, p<0.01) were highly significant. From the factor analysis, three groups such as city and traffic categories, economy category and environment category were identified to be the governing factors controlling GHG-AP emissions. The multiple regression analysis also represented that the most influencing factors on GHG-AP emissions were categories of traffic and environment. 25 administrative districts of Seoul were clustered into six groups, of which each has similar characteristics of urban spatial structures and GHG-AP integrated emissions.
도시화의 급격한 변화로 인한 불투수층의 증가는 도시 내의 강우유출수를 아무런 처리 없이 직접 도시 내에 유출되어 홍수, 첨두유량 증가 등의 문제점을 야기 시킨다. 이러한 문제점을 해결하기 위하여 미국, 유럽, 우리나라 등 많은 국가에서 개발 전 자연이 가지고 있던 수문학적 기능을 최대한 유지하면서 개발 후 발생되는 비점오염물질을 효율적으로 관리하는 저영향 개발 기술을 도입하고 있다. 따라서 본 연구에서는 도시지역 물순환 관리 및 비점오염물질 저감에 기여하고자 저류와 침투가 가능한 식생체류지를 개발 및 평가하고자 수행되었다.
본 연구는 식생체류지의 물순환 및 비점오염물질 저감 능력을 평가하기 위하여 공주대학교 내 주차장에 설치된 식생체류지의 모니터링을 수행하였다. 모니터링한 수질시료는 수질오염공정시험법에 준하여 입자상물질, 유기물, 영양물질 및 중금속에 대한 분석을 수행하였다. 또한 첨두유량 발생시간 및 지체시간, 첨두유량 저감 및 물수지를 산정하여 물순환 효과를 분석하였다.
식생체류지 시설의 모니터링은 2013년 11월부터 현재까지 총 11회가 수행되었으며 모니터링 결과, 강우유출수의 발생시간은 식생체류지를 적용하기 전에 비하여 약 40min 지체되는 것으로 나타났다. 또한 첨두유량의 발생 시간은 시설 적용 전에 비하여 약 80min 이후에 발생하는 것으로 분석되었으며, 첨두유량은 약 0.3m3/min 저감되는 것으로 나타났다. 물수지 산정 결과, 시설 내 저류 및 침투되는 양은 90%로 높은 물순환 효과를 나타낸 것으로 분석 되었다. 비점오염물질 저감효율을 산정한 결과, 모든 오염물질에서 90% 이상으로 높은 저감효율을 나타내는 것으로 분석되었다. 이는 여재부에서 일어나는 오염물질 저감 기작이 효과적으로 작용되는 것으로 판단된다.
This study focuses on analyzing the inflow characteristic of contaminants of city water that flows into a main water system like a reservoir, and intends to provide basic data which can be efficiently reflected on water quality management policy and decision making of a reservoir. The conclusion obtained from the analysis of the inflow of a main water system by analyzing the inflow property of city water contaminants is as follows. In the case of Chungju-cheon stream which is the city water, pollution load from the basic outflow is low when it rains, and with high load of basic outflow during the dry season, due to the discharge of pollutants from the city, the quality of water becomes worse. In the case of Chungju-cheon stream, average BOD is 4.53mg/ℓ when it rains, and the contaminants increase and flow in about 7.8% compared to the average BOD during the average ‧ droughty season. The average SS concentration in water is 798.67mg/ℓ and increased 97.2% compared to the average ‧ droughty season.
To investigate air quality away from the coastal urban source region, we used a hybrid Eulerian-Lagrangian method which can describe the formation, transport, transformation and deposition processes in complex terrain. with inclusion of shipping sources that were considered to be important emission in the coastal urban region. The result of the Eulerian advection - diffusion prediction was quite similar to that of the Lagrangian particle diffusion prediction. It showed that pollutants emitted from piers can affect the part of inland, especially Dongrae and the coastal area. Those emitted from Sasang and Janglim industrial complexes can affect Hwamyeong and the coastal, respectively. During the daytime the concentration was low due to large deposition flux and terrain effect.