• Title/Summary/Keyword: Urban Monitoring

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Seasonal Variation of PM2.5 and Its Major Ionic Components in an Urban Monitoring Site

  • Ghosh, Samik;Shon, Zang-Ho;Kim, Ki-Hyun;Song, Sang-Keun;Jung, Kweon;Kim, Nam-Jin
    • Asian Journal of Atmospheric Environment
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    • v.6 no.1
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    • pp.23-32
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    • 2012
  • The ionic composition of $PM_{2.5}$ samples was investigated by their datasets of cationic ($Na^+$, $NH_4^+$, $K^+$, $Mg^{2+}$, and $Ca^{2+}$) and anionic components ($Cl^-$, $NO_3^-$, and $SO_4^{2-}$) along with relevant environmental parameters collected from an urban monitoring site in Korea at hourly intervals in 2010. The mean (and SD) annual concentration of $PM_{2.5}$ was computed as 25.3 ${\mu}g\;m^{-3}$ with the wintertime maximum. In addition, sum concentrations (neq $m^{-3}$) of five cationic species (291) were slightly lower than 3 anionic species (308). Most cations exhibited the highest seasonal values in spring, while anions showed more diversified seasonal patterns. According to PCA, five major source categories were apparent with the relative dominance of secondary inorganic aerosols (SIA). The results of our study suggest consistently that the distribution of ionic constituents in an urban area is affected by the combined effects of both natural and anthropogenic processes.

KOMPSAT European Cooperation

  • Schiller C.;Triebnig G.;Kim Y.;Ahn S.;Moll B.;Kamp A. van der;Maass H.;Schwarz J.;Kressler F.
    • Proceedings of the KSRS Conference
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    • pp.154-157
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    • 2004
  • The KOMPSAT European Cooperation aims at enhancing existing and establishing new collaborations between KARI and various European institutions. The objective is to create mutual data and information exchange possibilities and to develop new data applications of available and future space based Earth Observation sensors. In this paper, the concept of a KOMPSAT regional application center, a joint development between KARI, ARCS and other European partners is presented. This includes the establishment of an additional KOMPSAT-2 downlink in Europe, and the developments of a state-of-the-art user service system for urban and environmental security monitoring.

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A Study on the Characteristics of Rural and Urban Surface Ozone Conentrations (청정지역과 도시지역의 오존농도 특성 연구)

  • 서명석;박경윤;이호근;장광미;강창희;허철구;김영준
    • Journal of Korean Society for Atmospheric Environment
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    • v.11 no.3
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    • pp.253-262
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    • 1995
  • A study has been performed on the characteristics of rural and urban surface ozone concentration for the period of March 1992 to February 1993. The monitoring station of rural ozone is located at Kosan, Cheju and other urban monitoring stations are located at Seoul, Pusan and Kwangju. Rural's and urban's ozone data exhibit a distinct features in many ways. First, annual mean of rural ozone concentration os very high(42 ppbv) but urban's are very low(10 .sim.15 ppbv). Second, rural ozone data shows a seasonal variation with it's maximum in spring, and minimum in summer, but urban's show a seasonal variation with it's maximum in spring, and minimum in winter. Third, diurnal variation of rural data is very small but that of urban's are very large. Fourth, urban's data are extremely low(< 3 ppbv) and have no seasonal variations.

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High Resolution InSAR Phase Simulation using DSM in Urban Areas (도심지역 DSM을 이용한 고해상도 InSAR 위상 시뮬레이션)

  • Yoon, Geun-Won;Kim, Sang-Wan;Lee, Yong-Woong;Lee, Dong-Cheon;Won, Joong-Sun
    • Korean Journal of Remote Sensing
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    • v.27 no.2
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    • pp.181-190
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    • 2011
  • Since the radar satellite missions such as TerraSAR-X and COSMO-SkyMed were launched in 2007, the spatial resolution of spaceborne SAR(Synthetic Aperture Radar) images reaches about 1 meter at spotlight mode. In 2011, the first Korean SAR satellite, KOMPSAT-5, will be launched, operating at X-band with the highest spatial resolution of 1 m as well. The improved spatial resolution of state-of-the-art SAR sensor suggests expanding InSAR(Interferometric SAR) analysis in urban monitoring. By the way, the shadow and layover phenomena are more prominent in urban areas due to building structure because of inherent side-looking geometry of SAR system. Up to date the most conventional algorithms do not consider the return signals at the frontage of building during InSAR phase and SAR intensity simulation. In this study the new algorithm introducing multi-scattering in layover region is proposed for phase and intensity simulation, which is utilized a precise LIDAR DSM(Digital Surface Model) in urban areas. The InSAR phases simulated by the proposed method are compared with TerraSAR-X spotlight data. As a result, both InSAR phases are well matched, even in layover areas. This study will be applied to urban monitoring using high resolution SAR data, in terms of change detection and displacement monitoring at the scale of building unit.

A Study on Implementaion of the GIS Based u-City urban Infrastructures (GIS기반 u-City 도시 인프라 구축에 관한 연구)

  • O, Jong-U;O, Seung-Hun
    • 한국디지털정책학회:학술대회논문집
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    • pp.379-386
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    • 2006
  • The purpose of this paper is to analyze the implementation of the GIS infrastructure systems for the u-City, GIS base u-City represents spatial information derived fields, such as geographical distribution of the urban boundaries, physical configuration of the urban locations and cultural characteristics of the urban history. These three aspects relate to urban infrastructure systems implementation, urban monitoring center implementation, and spatial database implementation. In terms of the GIS based u-Ci쇼 urban infrastructure implementation systems, the u-City depends on IT contents and spatial features. IT contents are strongly related to IT839 strategy due to the national agenda is "u-Korea". GIS should contribute to u-City construction through the spatial analyses methods. For these methods various GIS functions will guide to u-City's distribution, location, and characteristics of urbanization. The infrastructure consists of road and road facilities, underground facilities, related agencies facilities, dispatch systems, environmental systems, and urban planning. These six units of the urban infrastructures have spatial databases that consist of spatial configuration, such as dots, lines, and polygons in order to draw the spatial distribution of the u-City GIS based u-City urban infrastructure implementation systems should deal with It convergence to generate fusion affects.

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Photochemical Conversions of Reduced Sulfur Compounds to SO2 in Urban Air (도시의 환원 황 화합물의 이산화황으로의 광화학적 변환)

  • Shon, Zang-Ho;Kim, Ki-Hyun
    • Journal of Korean Society for Atmospheric Environment
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    • v.20 no.5
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    • pp.647-654
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    • 2004
  • This study examines the local oxidation chemistry of reduced sulfur compounds (RSC) in the urban air. The chemical conversion of RSC (such as DMS, $CS_2,\;H_2S,\;DMDS,\;and\;CH_3SH)\;to\;SO_2$ was modeled using a photochemical box model. For our model prediction of the RSC oxidation, measurements were carried out from an urban monitoring station in Seoul (37.6$^{\circ}$N, 127.0$^{\circ}$E), Korea for three separate time periods (Sep. 17~18; Oct 23; and Oct. 27~28, 2003). The results of our measurements indicated that DMS and $H_2S$ were the dominant RSC with their concentrations of 370${\pm}$140 and 110${\pm}$60 pptv, respectively. The conversion of DMDS to $SO_2$ can occur efficiently in comparison to other RSC, but it is not abundant enough to affect their cycles. The overall results of our study indicate that the photochemical conversion of the RSC can contribute ≶ 20% of the observed $SO_2$.

Case study of ozone photochemistry in the Seoul metropolitan area during the summer 2003 (2003년 여름동안 서울지역에서의 오존의 광화학적 특성에 대한 사례 연구)

  • Shon Zang-Ho
    • Journal of Environmental Science International
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    • v.14 no.8
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    • pp.749-760
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    • 2005
  • This study examines the local ozone photochemistry in the urban air. The photochemical formation and destruction of ozone was modeled using a photochemical box model. For the model prediction of ozone budget, measurements were carried out from an urban monitoring station in Seoul ($37.6^{\circ}N,\;127^{\circ}E$), Korea for intensive sampling time period (Jun. $1\~15$, 2003). Photochemical process is likely to play significant role in higher ozone concentrations during the sampling period. The results of model simulation indicated that photochemical ozone production pathway was the reaction of NO with $HO_2$ while ozone destruction was mainly controlled by a photochemical destruction pathway, a reaction of $H_2O$ with $O(^1D).$ The contribution of NMHCs to formation and destruction of ozone in the urban was significant. This was entirely different from remote marine environment. The rates of net photochemical ozone production ranged from 0.1 to 1.3 ppbv $h^{-1}$ during the study period.

An Assessment Study for the Urban Air Monitoring Network in Seoul (서울지역 도시대기측정망 평가 연구)

  • Ghim, Young Sung;Choi, Yongjoo;Park, Ji Soo;Kim, Chan Hyuk
    • Journal of Korean Society for Atmospheric Environment
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    • v.30 no.5
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    • pp.504-509
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    • 2014
  • Twenty-five stations of the urban monitoring network in Seoul were assessed with a focus on surveillance function of the exceedances of 8-hour ozone and 24-hour $PM_{10}$ standards. The two standards were selected because their attainment rates were particularly low. Two hierarchical cluster analyses were performed to group stations with similar atmospheric environments-one using daily highest 8-hour [$O_3+NO_2$], 8-hour $O_3$ concentrations plus corresponding 8-hour $NO_2$ concentrations considering the interconversion of $O_3$ and $NO_2$, and the other using 24-hour $PM_{10}$ concentrations. An index to measure higher concentration and exceedances of the standards was introduced. Within a cluster, sufficiently high score was assigned to the trends station or the station with higher index. Scores for $O_3+NO_2$ and $PM_{10}$ of a given station were added and ranked in the descending order to determine the relative importance.

A study on Land use Survey and Monitoring Forcused on the Subway Station Areas in Taejeon (도시철도 역세권의 공간이용 모니터링을 위한 기초연구)

  • Cho, Byung-Ho;Choi, Bong-Moon
    • The Journal of the Korea Contents Association
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    • v.11 no.2
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    • pp.457-465
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    • 2011
  • This research, which was started with a need for constant monitoring to find out urban societies and spacial effects by urban railway after the opening, was intended to empirically explore urban and social changes by the opening of Daejeon City metro line 1st which would greatly affect the spacial structure of the city. For this goal, we expected the effect of urban subway on the city with academic consideration and precedent study. Monitoring results of the subway station areas of Daejeon City metro line 1st showed the opening of urban railway had an influence on the flow of urban plan and urban space structure through population, land use, total-developing areas, and land price change. In other words, as urban railway opens the number of population and population activities centered on the subway station areas, and these movements led to the expansion of the commercial areas. Finally, they caused the average land prices to rise. Likewise, urban monitering is significantly useful comprehending the generally time-periodic changes of cities and even conceiving the present cities.

Changes in Demographic and Housing Characteristics of New Towns in Korea: Focused on Five New Towns in Seoul Metropolitan Area (우리나라 신도시의 인구 및 주거특성 변화: 분당, 일산 등 1기 신도시를 중심으로)

  • Yoon, Jeong-Joong;Kim, Eun-Mi
    • LHI Journal of Land, Housing, and Urban Affairs
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    • v.5 no.4
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    • pp.235-246
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    • 2014
  • In the late 1980s, 5 new towns such as Bundang, Ilsan, Pyeongchon, Sanborn, Jungdong were constructed to solve housing problems and to disperse functions concentrated within Seoul. As the city got matured, it began to appear the initial signs of urban problems such as aging of high rise-density apartment sites, traffic congestion, lack of parking spaces and aging of infrastructure. Therefore, in order to cope with urban problems, it is very important to apprehend the process of urban growth, its change and the feature of physical/human elements. So, the purpose of this thesis is to analyze the changes in housing and population characteristics for past 20 years by use of Census data from 1995 to 2010. First, the new town's goal of population and housing plan at the time of construction was analyzed how it was achieved, and it is close to the performance of the goal. And the trend of changes in the population and household characteristics was analyzed by every five year's data. As the result of analysis, it shows socio-demographic changes such as aged and elderly population growth, rapid increase in one generation's household and single person household, highly educated city, monthly rent household's increase and charter household's reduction. Results of this analysis can be utilized to aforethought management of new towns. But it is required more sustained and systematic urban monitoring and data analysis because the one-off analysis of the city's characteristics alone is difficult enough to grasp them.