• Title/Summary/Keyword: Urban environment

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Urban Thermo-profiles and Community Structure of Quercus mongolica Forests along an Urban-rural Land Use Gradient: Implications for Management and Restoration of Urban Ecosystems

  • Cho, Yong-Chan;Cho, Hyun-Je;Lee, Chang-Seok
    • Journal of Ecology and Environment
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    • v.32 no.3
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    • pp.167-176
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    • 2009
  • Land cover changes associated with urbanization have driven climate change and pollution, which alter properties of ecosystems at local, regional, and continental scales. Thus, the relationships among urban ecological variables such as community composition, structure, health, soil and functioning need to be better understood to restore and improve urban ecosystems. In this study, we discuss urban ecosystem management and research from a futuristic perspective based on analyses of vegetation structure, composition, and successional trends, as well as the chemical properties of soils and the distribution of heat along an urban-rural gradient. Urban thermo-profile analysis using satellite images showed an obvious mitigating effect of vegetation on the Seoul heat island. Community attributes of Quercus mongolica stands reflected the effects of urbanization, such as pronounced increases in disturbance-related and pollution-tolerant species, such as Styrax japonica and Sorbus alnifolia. Retrogressive successional trends were detected in urban sites relative to those in rural sites. Changes in the urban climate and biotic environment have the potential to significantly influence the practice and outcomes of ecological management, restoration and forecasting because of the associated changes in future bio-physical settings. Thus, for management (i.e., creation and restoration) of urban green spaces, forward-thinking perspectives supported by historical information are necessary.

Research on the Accessibility of Urban Green Space Based on Road Network- A Case Study of the Park Green Space in City Proper of Nanjing

  • Fan, Yong;Zhao, Ming-yuan;Ma, Lin;Zhao, Lan-yong
    • Journal of Forest and Environmental Science
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    • v.32 no.1
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    • pp.1-9
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    • 2016
  • Accessibility of urban green space, as an important index of evaluating the service level of urban green space, not only shows the resident's access to green space, but also reflects the environment quality of urban living. Since the quantity, area and space distribution of the patches in urban green space directly affect the function of urban green space and the quality of urban environment, the research on the accessibility of urban green space holds great significance to improve the service of urban green space and the living environment quality. Based on GIS software, this research uses the road network and the population distribution data of Nanjing's city proper to conduct quantitative analysis of the accessibility of park green space and the convenience for residents to travel under different forms of transportation. After the case analysis, the author tests the application of road network in studying the accessibility of urban park green space and proposes a GIS-based method to study the accessibility and the rational layout of urban green space.

Butyric Acid Fermentation of Sodium Hydroxide Pretreated Rice Straw with Undefined Mixed Culture

  • Ai, Binling;Li, Jianzheng;Chi, Xue;Meng, Jia;Liu, Chong;Shi, En
    • Journal of Microbiology and Biotechnology
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    • v.24 no.5
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    • pp.629-638
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    • 2014
  • This study describes an alternative mixed culture fermentation technology to anaerobically convert lignocellulosic biomass into butyric acid, a valuable product with wide application, without supplementary cellulolytic enzymes. Rice straw was soaked in 1% NaOH solution to increase digestibility. Among the tested pretreatment conditions, soaking rice straw at $50^{\circ}C$ for 72 h removed ~66% of the lignin, but retained ~84% of the cellulose and ~71% of the hemicellulose. By using an undefined cellulose-degrading butyrate-producing microbial community as butyric acid producer in batch fermentation, about 6 g/l of butyric acid was produced from the pretreated rice straw, which accounted for ~76% of the total volatile fatty acids. In the repeated-batch operation, the butyric acid production declined batch by batch, which was most possibly caused by the shift of microbial community structure monitored by denaturing gradient gel electrophoresis. In this study, batch operation was observed to be more suitable for butyric acid production.

Analysis of Radiative Characteristics at Urban Area by Observation in Summer Season (하절기 도시의 지역별 장.단파복사 특성 분석과 해석)

  • Jung, Im-Soo;Choi, Dong-Ho;Lee, Bu-Yong
    • Journal of the Korean Solar Energy Society
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    • v.31 no.3
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    • pp.133-144
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    • 2011
  • The objective of this study is to analyze the characteristic of radiation environment in the urban and rural through the field observation in the summer. The radiation balance was compared through the measurement of the shortwave radiation and long-wave radiation in the urban, sub-urban, and rural. The following conclusion could be obtained from this research. (1)In the results of observation including the rain-day, it was found that the short wave radiance in the urban is lower about 10% than the rural. (2)The upper part of atmosphere layers in the urban are aabsorb much short wave radiation energies compared with the rural relatively. It can increase the temperature of the upper part of atmosphere layers and the emittance of long wave radiation. (3)The ratio of the downward short wave radiation to the downward long wave radiation was 1.24 for the urban, 1.28 for sub-urban and 1.35 for rural. It can be estimated that the atmosphere condition of the rural is better than that of other areas. (4)The net radiation of the rural was lower that of the urban. It was found that the energy in and outflow of the rural is easier than that of the urban. (5)The temperature variation for the long-wave radiation change of the rural showed more sensitive than that of the urban. It was came from the radiation characteristics of the surrounding environment and can be used as the important index to evaluate the thermal environment characteristic of urban.

Analysis of the Relationship between Three-Dimensional Built Environment and Urban Surface Temperature (도시의 3차원 물리적 환경변수와 지표온도의 관계 분석)

  • Li, Yige;Lee, Sugie;Han, Jaewon
    • Journal of Korea Planning Association
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    • v.54 no.2
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    • pp.93-108
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    • 2019
  • This study examines the relationship between three-dimensional urban built environment and urban surface temperature using LANDSAT 8 satellite image data in Seoul city. The image was divided into 600m×600m grid units as an unit of analysis. Due to the high level of spatial dependency in surface temperature, this study uses spatial statistics to take into account spatial auto-correlation. The spatial error model shows the best goodness of fit. The analysis results show that the three-dimensional built environment and transport environment as well as natural environment have statistically significant associations with surface temperature. First, natural environment variables such as green space, streams and river, and average elevation show statistically significant negative association with surface temperature. Second, the building area shows a positive association with surface temperature. In addition, while sky view factor (SVF) has a positive association with surface temperature, surface roughness (SR) shows a negative association with it. Third, transportation related variables such as road density, railway density, and traffic volume show positive associations with surface temperature. Moreover, this study finds that SVF and SR have different effects on surface temperature in regard to the levels of total floor areas in built environment. The results indicate that interactions between floor area ratio (FAR) and three-dimensional built environmental variables such as SVF and SR should be considered to reduce urban surface temperature.

Development Guidelines of Environmental planning Indicators for Environmentally friendly Urban and Architectural Planning (친환경적 도시건축계획을 위한 환경계획지표개발의 방향)

  • Chang, Dong-Min
    • KIEAE Journal
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    • v.1 no.2
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    • pp.5-12
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    • 2001
  • Through the harmony of natural and artificial systems a city is composed of, the ecology-oriented urban planning seeks for qualitative improvements of a city on which our life is based. To enhance the ecology-oriented urban planning, the followings are suggested by a comparative analysis of Korea with Germany regarding the development process, the instruments, and the establishment of indicators for the planning. Firstly, though our national land development plan is closely connected with B-plan, it has little to do with the natural environment. Moreover, the natural environment plan of the Ministry of Environment is almost impossible to carry out in terms of urban construction work. For this reason, the instrument for dealing with the development and environment plan systems together as well as the completion of the current plan system is needed for the ecologically acceptable urban development in the long term. Secondly, in order to realize what is mentioned above in the concrete it seems to be desirable for the system and the instrument to be devised at the extent of B-plan. The regulations of the plan should have strong legal binding force and practicality as well. The element of ecology-oriented urban planning are (1) degree of independence and appropriate density, (2) conservation of natural elements such as soil, water, animals and plants etc., (3) energy saving in land use, (4) activation of B-plan and inducement of active participation of residents. Thirdly, it will be useful to develop various kinds of indicators for the environment plan provided in advance so that the ecology-oriented urban developments may be under control. It also should be taken into consideration that the indicators are supposed to be comprehensive, representative, and practical enough to make the most of at the early stage of drawing up a plan. The kinds of indicators which can be used in the ecology-oriented urban development include (1) soil, (2) water, (3) vegetation and plants, (4) animals, (5) climate, and (6) transportation.

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An Analysis on the Variation Trend of Urban Heat Island in Busan Area (2006-2010) (부산지역 도시 열섬의 변화경향 분석 (2006-2010))

  • Do, Woo-Gon;Jung, Woo-Sik
    • Journal of Environmental Science International
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    • v.21 no.8
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    • pp.953-963
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    • 2012
  • The annual variations of the urban heat island in Busan is investigated using surface temperature data measured at 3 automatic weather stations(AWSs) for the 5 years period, 2006 to 2010. Similar to previous studies, the intensity of the urban heat island is calculated using the temperature difference between downtown(Busanjin, Dongnae) and suburb(Gijang). The maximum hourly mean urban heat island are $1.4^{\circ}C$ at Busanjin site, 2300LST and $1.6^{\circ}C$ at Dongnae site, 2100LST. It occurs more often at Dongnae than Busanjin. Also the maximum hourly mean urban heat island appears in November at both sites. The urban heat island in Busan is stronger in the nighttime than in the daytime and decreases with increasing wind speed, but it is least developed in summer. Also it partly causes the increasement of nighttime PM10 concentration.

Exploring Potentials of GIS Application in Urban Planning and Design from Interdiscipline Viewpoint

  • Jin-yeu, TSOU;Yucai, XUE
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.795-797
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    • 2003
  • GIS can supply large quantitiy of useful information about spacial relationship, consequently there exists great potential of GIS support ing for decision making strategies related to urban design and environmental planning. In different discipline areas there exist different information representation methods and considerations having direct or indirect relationship with spacial information, how to use GIS as a tool for facilitating the work in other discipline field, there are two basic questions crucial to the success of these interdiscipline applications. The first one is interoperatability among GIS and other applications, the second is the paradigm difference between GIS and other domain field regarding problem solving. In this paper, we investigate the spatial information of the urban environment provided in the analyses of the urban visual sustain ability, urban daylighting environment and urban wind environment. We also discuss the challenges and opportunities for cross-disciplinary GIS application regarding the aspect of Information Collection, Information Generation, Information Analysis and Information Visualization.

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Numerical Simulation on the Effect of the Land Coverage Change on the Urban Heat Budget (토지피복 변화가 도시열수지에 미치는 영향에 관한 수치시뮬레이션)

  • Kim, Sang-Ok;Yeo, In-Ae;Ha, Kyung-Min;Yee, Jurng-Jae;Yoon, Seong-Hwan
    • 한국태양에너지학회:학술대회논문집
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    • 2009.04a
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    • pp.176-179
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    • 2009
  • In this study, Urban Climate Simulation was performed using 3-Dimensional Urban Canopy Model. The characteristics of urban thermal environment was analyzed by classifying land coverage and increasing natural land coverage ratio. The results are as follows. The characteristics of the land coverage on urban thermal environment formation can be summarized by the effects like higher temperature on the artificial coverage, and the contrary effects on the natural coverage. When the water coverage 100% was made up, maximum temperature was declined by $5.5^{\circ}C$, humidity by the 6.5g/kg, wind velocity by 0.6m/s, convective sensible heat by $400W/m^2$ and the evaporative latent heat was increased by $370W/m^2$ compared to when artificial coverage 100% was formed. These simulation results need to be constructed as DB which shows urban quantitative thermal characters by the urban physical structure. These can be quantitative base for suggesting combinations of the building and urban planning features at the point of the desirable urban thermal environment as well as analysing urban climate phenomenon.

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An Interpretation of Dualistic Relationships in an Urban Renewal Landscape Based on the Iching Theory - the Case of Gongpyeong District in Seoul - (괘상원리에 기초한 도심재개발 경관의 이원관계의 해석 - 서울 공평구역을 사례로 -)

  • 홍윤순
    • Journal of the Korean Institute of Landscape Architecture
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    • v.30 no.5
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    • pp.16-30
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    • 2002
  • This study tried to understand an ambiguous urban landscape through a relational context. Gongpyeong district, an urban renewal area in Seoul, was selected as the site of the case study because traditional and modern styles coexist in this district. The research method and processes are summarized as follows. First, the district, which has both a redeveloped environment and an inherent environment, was divided into Yin & Yang structures. Next, an effort was made to grasp the fundamental relational characteristics(external relationships) of each type through three aspects: physical environment, activities, and meaning. As a result, Yin characteristics were found in the redeveloped environment which has predominantly Yang characteristics. In many cases, advertising, which is a Yang element, was missing in the redeveloped area. On the other hand, in the inherent environment which has Yin characteristics in general, shabby appearances were evident in aspects beyond advertising, and Yang elements, were found from the viewpoint of the theory of place. On the basis of these results, new dualistic frameworks with respect to the functions were re-structured, and complementary characteristics (internal relationship) based on topological aspects were analyzed. Unlike the monotonous appearances found in large scale environments, a variety of spatial characteristics were found in the various small scale environments. This explains that the dualistic coexistence has made a contribution to the complementary attributes of urban landscape. This study has the following ramifications. Much research of urban landscapes that has used western methodology which employs analytic aspects. As a methodology of urban landscape research this study introduced Iching, which tries to understand phenomena in a relational context. In addition, this study expects that the profound understanding of urban environments and the detailed relationship through this framework will suggest a new approach to urban planning, design and management related to future urban environments.