• Title/Summary/Keyword: urban characterization

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VARIOGRAM-BASED URBAN CHARACTERIZATION USING HIGH RESOLUTION SATELLITE IMAGERY

  • Yoo, Hee-Young;Lee, Ki-Won;Kwon, Byung-Doo
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.413-416
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    • 2006
  • As even small features can be classified as high resolution imagery, urban remote sensing is regarded as one of the important application fields in time of wide use of the commercialized high resolution satellite imageries. In this study, we have analyzed the variogram properties of high resolution imagery, which was obtained in urban area through the simple modeling and applied to the real image. Based on the grasped variogram characteristics, we have tried to decomposed two high-resolution imagery such as IKONOS and QuickBird reducing window size until the unique variogram that urban feature has come out and then been indexed. Modeling results will be used as the fundamental data for variographic analysis in urban area using high resolution imagery later on. Index map also can be used for determining urban complexity or land-use classification, because the index is influenced by the feature size.

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Size Characterization of Urban Airborne Particles Using Sedimentation/Steric Field-Flow Fractionation (Sd/StFFF)

  • Lee, Jae-Yong;Lee, Seung-Ho;Min, Young-Hong;Hyun, Dae-Yeung
    • Bulletin of the Korean Chemical Society
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    • v.24 no.8
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    • pp.1172-1176
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    • 2003
  • This study aims to investigate the applicability of Sd/StFFF and to develop a method for size characterization of urban airborne particles, focusing primarily on particles larger than about 1 mm. It was found that the airborne concentration vary with time, although no particular seasonal trend was observed. When averaged over time, the airborne concentration was the lowest in the park areas with 99 ㎍/m³. The apartment, industrial, and central city area showed similar levels of the airborne concentrations with 166, 170, and 171 ㎍/m³, respectively. The housing area showed the highest airborne concentration with 201 μg/m³ among all tested areas. A power-programmed Sd/StFFF was used for size analysis of airborne particles with the initial field strength of 300 rpm, $t_a$ = 4, $t_i$ = -16, p = 8, and the flow rate of 7 mL/min. It was found that urban airborne samples were mostly populated by particles having diameters between about 5 to 20 ㎛, although all have broad size distributions ranging up to about 50 ㎛. Under the Sd/StFFF condition used in this study, no significant differences were found in size distributions among the airborne particles collected at different urban sites, and also among those collected at different times.

Characterization of Individual Atmospheric Aerosols Using Quantitative Energy Dispersive-Electron Probe X-ray Microanalysis: A Review

  • Kim, Hye-Kyeong;Ro, Chul-Un
    • Asian Journal of Atmospheric Environment
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    • v.4 no.3
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    • pp.115-140
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    • 2010
  • Great concerns about atmospheric aerosols are attributed to their multiple roles to atmospheric processes. For example, atmospheric aerosols influence global climate, directly by scattering or absorbing solar radiations and indirectly by serving as cloud condensation nuclei. They also have a significant impact on human health and visibility. Many of these effects depend on the size and composition of atmospheric aerosols, and thus detailed information on the physicochemical properties and the distribution of airborne particles is critical to accurately predict their impact on the Earth's climate as well as human health. A single particle analysis technique, named low-Z particle electron probe X-ray microanalysis (low-Z particle EPMA) that can determine the concentration of low-Z elements such as carbon, nitrogen and oxygen in a microscopic volume has been developed. The capability of quantitative analysis of low-Z elements in individual particle allows the characterization of especially important atmospheric particles such as sulfates, nitrates, ammonium, and carbonaceous particles. Furthermore, the diversity and the complicated heterogeneity of atmospheric particles in chemical compositions can be investigated in detail. In this review, the development and methodology of low-Z particle EPMA for the analysis of atmospheric aerosols are introduced. Also, its typical applications for the characterization of various atmospheric particles, i.e., on the chemical compositions, morphologies, the size segregated distributions, and the origins of Asian dust, urban aerosols, indoor aerosols in underground subway station, and Arctic aerosols, are illustrated.

Density Distributions of Metallic Compounds in Particulate Matters (粒子狀 物質中 金屬成分의 密度分布)

  • 허문영;김형춘;손동헌
    • Journal of Korean Society for Atmospheric Environment
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    • v.2 no.2
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    • pp.9-18
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    • 1986
  • For identification and apportionment of sources emitting particulate matters in environment, the multi-elemental characterization of size-density fractionated particulate matters was carried out. Eight types of samples were tested; soil, flyash released from burning of bunker-Coil, diesel oil, coal, and soft coal, urban road-way dust, urban dust fall, and airborne particulate matter. The fractions of particulate matters obtained by heavy liquid separation methos with a series of dichloromethane-bromoform were then analyzed using atomic absorption spectrophotometry for Ni, Cr, Cu, An, Fe, Al, and Mg. Each sample showed a different concentration profile as a function of density, and a number of useful conclusions concerning characterization of elemental distribution were obtained. From the density distributions of elements in soil, the maximum value was found for all elements in the density range of 2.2 $\sim 2.9g.cm^{-3}$, including the density of $SiO_2$. However, the distribution of metallic compounds with the density lower than $2.2g.cm^{-3}$ was prevalent in urban roadway dust, urban dust fall, and airborne particulate matter. And the density distribution curves of these urban dusts also have the higher distribution at the density of 2.2 - 2.9g.cm^{-3}$, including the density of wind-blown silica. This tendency generally was prevalent in the natural source elements, such as Al, Fe, Mn, and Mg. The maximum values were found in the density ranges of 1.3 $\sim 2.2g.cm^{-3}$ from the density distribution of elements in oil fired flyash. These distributions of anthropogenic source elements, such as Zn, Ni, Cu, and Cr were higher predominately than those of natural source elements. And the higher distribution was found in the density range of $2.2 \sim 2.9g.cm^{-3}$ from the density distribution of elements in coal and soft-coal fired flyash. These distributions showed similar patterns to soil. But anthropogenic source elements somewhat predominated at the density ranges of $1.3 \sim 2.2g.cm{-3} and 2.9g.cm^{-3}$ to soil. Therefore the higher distribution of anthropogenic source elements in the density ranges of $1.3 \sim 2.2g.cm^{-3} and 2.9g.cm^{-3}$ was considered as anthropogenic origin.

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CHARACTERIZATION OF NONPOINT SOURCES FROM URBAN RUNOFF

  • Park, Jae-Young;Jo, Young-Min;Oh, Jong-Min
    • Water Engineering Research
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    • v.1 no.1
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    • pp.39-48
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    • 2000
  • This work was completed in partial fulfillment of an on-going research ot descover the effective management of urban nonpoint sources. The current data was obtained from the area of Shingal, Kyunni-do. The investigation was are predominant soures of storm-runoff load and drainage. As a result of the investigation, the road was found to be most seriously contaminated and a significant potential source deteriorating the quality of streams and lakes in the vicinity of the town. Thus, in could be concluded that an effective and systematic cleaning technique must be developed as soon as possible and be frequently applied to the road.

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Source Characterization of Suspended Particulate Matter in Taegu Area, Using Principal Component Analysis Coupled with Multiple Regression (주성분/중회귀분석을 이용한 대구지역 대기중 부유분진의 발생원별 특성평가)

  • 백성옥;황승만
    • Journal of Korean Society for Atmospheric Environment
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    • v.8 no.3
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    • pp.179-190
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    • 1992
  • This study was carried out to characterize sources of atmospheric total suspended particulates (TSP) in urban and sub--urban areas of metropolitan taegu. The sources were tentatively identified by a multivariate technique, i.e. principal component analysis (PCA), and the source contributions to the atmospheric concentrations of TSP were further estimated by stepwise multiple regression analysis. A total of 5 sources was identified in the urban area of Taegu (soil dust resuspension, fuel combustion, secondary aerosol, traffic related aerosol, and refuge burning), while 4 sources were found to be significant in the sub--urban area as following: fuel combustion/secondary aerosol, soil dust resuspension, traffic related aerosol, and wood/agricultural burning. The largest contributor to the atmospheric TSP appeared to be the soil dust resuspension in both areas. The source apportionment of the extractable organic matter (EOM) was also carried out for the Taegu data. The EOM was determined with respect to the solvent polarity, i.e. cyclohexane (non-polar), dichloromethane (semi--polar), and acetone (polar). In addition, the source profiles for the TSP in Taegu area were estimated using a PCA-based algorithm, and the validity was evaluated tentatively by comparing the data in the literature.

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Characterization of Combined Sewer Overflows from a Small Urban Watershed and Determination of Optimum Detention Volume (소규모 도시유역 합류식 하수관거 월류수 특성화 및 최적 저류지 용량 결정)

  • Jo, Deokjun;Kim, Geonha
    • Journal of Korean Society on Water Environment
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    • v.22 no.2
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    • pp.314-320
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    • 2006
  • Diffuse pollution from an urban area contributes to the significant pollution loading to a receiving water body. In this paper, rainfall runoffs from an urban basin with combined sewer systems located in the city of Daejeon were monitored to measure the rainfall runoff discharge rates and pollutant concentrations. Strong first flush effects were observed for all monitored rainfall runoffs. The first flush effects were closely related to rainfall intensity, while suspended solids were closely related to pollutant constituents. The observed averaged Event Mean Concentrations (EMCs) of Combined Sewer Overflows (CSOs) were 536.1 mg SS/L, 467.7 mg CODcr/L, 142.7 mg BOD/L, 16.5 mg TN/L, and 13.5 mg TP/L. Storage volumes for containing the first flush to improve water quality of the receiving stream can be estimated based on suspended solid concentration. In this study, retainment of the first flush equivalent to 5mm of precipitation could reduce diffuse pollution loading induced by CSOs to a receiving water body by up to 80% of suspended solid loading.

A Study on the Spatial Characteristics Analysis of the Urban Public Space, applying a Pattern Language (패턴 언어를 적용한 공공공간의 공간적 특성 분석에 관한 연구)

  • Lee, Hoon-Gill;Lee, Joo-Hyung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.8
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    • pp.5608-5618
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    • 2015
  • This study conducted a spatial characterization of the public space using the pattern language of Christopher Alexander. It is the place which the city offers the human various experience. Urban public space has played an important role in flourishing public life through history. It has been a place for communication, cultural events, commercial exchange recreation, etc. among people in the city. But today, various behavior in public space and public life are declined. One of the reason in neglecting the user's need when urban space are planned and managed. This study examined the role and types of urban public space through literature survey and found the reason for its decline. For this public space spatial characteristics and indicators by FGI(Focus Group Interview) derived through. After those, case study was examined Jongro in Seoul and analyzed the spatial characteristics of the urban public space in a pattern language. Consequently, this study presents suitable a space structure direction of the public space and do for rather abundant a city space furtherance.

Characterization of the Butterfly Community of a Fragmented Urban Forest, Hongneung Forest (격리된 도시숲, 홍릉숲 나비군집의 특성)

  • Lee, Cheol Min;Kwon, Tae-Sung
    • Korean journal of applied entomology
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    • v.51 no.4
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    • pp.317-323
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    • 2012
  • Fragmented urban forests, as green islands within urban area, are the primary habitats for a vast number of different organisms inhabiting large cities. The areas of the urban forests are usually small, and hence, the proportion of the forest edge is relatively high. It is therefore expected that overall butterfly diversity may be lower than that of suburban or rural forests, and that those of grassland species, forest edge species, and generalist species with a wider niche breadth may be richer. Butterflies were surveyed weekly by the line transact method in order to characterize the butterfly community of the Hongneung Forest, a fragmented urban forest in Seoul. Butterfly richness of the study forest is much lower than those of main forests around or in Seoul. Grassland species, forest edge species, and generalist species were found to be richer, which was in agreement with the expected patterns of urban butterfly communities. Also, an endangered species, Spindasis takanonis, was observed in the Hongneung Forest, showing that urban forests play important roles for conservation of rare species.