• Title/Summary/Keyword: Urban changes

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Changes in nocturnal insect communities in forest-dominated landscape relevant to artificial light intensity

  • Lee, Hakbong;Cho, Yong-Chan;Jung, Sang-Woo;Kim, Yoon-Ho;Lee, Seung-Gyu
    • Journal of Ecology and Environment
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    • v.45 no.4
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    • pp.218-227
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    • 2021
  • Background: Artificial light at night has recently been identified as a major factor adversely affecting global insect diversity. Here, we compared the insect diversity in Gwangneung Forest Biosphere Reserve, specifically in the Korea National Arboretum (with no artificial light at night), with that of three nearby urban sites with a gradient of artificial light at night (five locations at each site). We analyzed the effects of the artificial night lighting index, mean annual temperature, and field light intensity (lux) at night on the insect community structure. Results: The urban sites generally exhibited higher species richness and abundance as well as clear indicator species compared with the control site. The size distribution of the collected insects markedly differed between the control and the three urban sites. The abundance of herbivorous and omnivorous insects increased and decreased, respectively, with the increase in light intensity. Species richness of herbivorous and omnivorous insects was likely correlated with the field light intensity at night and artificial night lighting index, respectively. Conclusions: This study demonstrates the association between nighttime environment and marked changes in insect community structure and revealed consequent transition of ecosystem services by changes in trophic group composition.

Effect of Bacterial Wilt on Fungal Community Composition in Rhizosphere Soil of Tobaccos in Tropical Yunnan

  • Zheng, Yuanxian;Wang, Jiming;Zhao, Wenlong;Cai, Xianjie;Xu, Yinlian;Chen, Xiaolong;Yang, Min;Huang, Feiyan;Yu, Lei;He, Yuansheng
    • The Plant Pathology Journal
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    • v.38 no.3
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    • pp.203-211
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    • 2022
  • Bacterial wilt, which is a major soil-borne disease with widespread occurrence, poses a severe danger in the field of tobacco production. However, there is very limited knowledge on bacterial wilt-induced microecological changes in the tobacco root system and on the interaction between Ralstonia solanacearum and fungal communities in the rhizosphere soil. Thus, in this study, changes in fungal communities in the rhizosphere soil of tobaccos with bacterial wilt were studied by 18S rRNA gene sequencing. The community composition of fungi in bacterial wilt-infected soil and healthy soil in two tobacco areas (Gengma and Boshang, Lincang City, Yunnan Province, China) was studied through the paired comparison method in July 2019. The results showed that there were significant differences in fungal community composition between the rhizosphere soil of diseased plants and healthy plants. The changes in the composition and diversity of fungal communities in the rhizosphere soil of tobaccos are vital characteristics of tobaccos with bacterial wilt, and the imbalance in the rhizosphere microecosystem of tobacco plants may further aggravate the disease.

A Study on the Urban Heat Simulation Model Incorporating the Climate Changes (기후변화가 반영된 도시 열환경 시뮬레이션 모델의 연구)

  • Kang, Jonghwa;Kim, Wansoo;Yun, Jeongim;Lee, Joosung;Kim, Seogcheol
    • Journal of Korean Society for Atmospheric Environment
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    • v.34 no.5
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    • pp.697-707
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    • 2018
  • A fast running model comprising the climate change effects is proposed for urban heat environment simulations so as to be used in urban heat island studies and/or the urban planning practices. By combining Hot City Model, a high resolution urban temperature prediction model utilizing the Lagrangian particle tracing technique, and the numerical weather simulation data which are constructed up to year of 2100 under the climate change scenarios, an efficient model is constructed for simulating the future urban heat environments. It is applicable to whole city as well as to a small block area of an urban region, with the computation time being relatively short, requiring the practically manageable amount of the computational resources. The heat environments of the entire metropolitan Seoul area in South Korea are investigated with the aid of the model for the present time and for the future. The results showed that the urban temperature gradually increase up to a significant level in the future. The possible effects of green roofs on the buildings are also studied, and we observe that green roofs don't lower the urban temperature efficiently while making the temperature fields become more homogeneous.

The Improvement Method for Air Pollution Level through Optimal Allocation of Urban Facilities( I ) (도시시설의 도로기능별 적정입지분석을 통한 대기오염 저감방안에 관한 연구( I ))

  • Kwon, Woo-Taeg;Kim, Hyung-Chul;Kim, Ki-Bum
    • Journal of environmental and Sanitary engineering
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    • v.18 no.3 s.49
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    • pp.11-20
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    • 2003
  • There are two ways of reducing air pollution. One is the approach of the pollutant source control and the other one is the traffic demand decreasing approach. This study is focusing on the approach of land use planning and optimal location of urban facilities because those are the basic cause to generate transportation demands. So, the purpose of this study would be to analyze the changes of NOx and CO distribution on environmental air by functional hierarchy of urban roads and to make evaluation model of 'Transportation-Land Use -Air Pollution'. It will contribute to improve the air pollution level at same actual traffic generation according to different location.

Analysis on Change Characteristics of Spatial Structure Related with Urban Planning : Using Spatial Statistical Method (도시계획과 연계한 공간구조의 변화 특성 분석 - 공간통계기법을 이용하여)

  • Seo, Kyung-Min;Kim, Ho-Yong;Lee, Sung-Ho;Kwon, Tae-Ho
    • Journal of the Korean Association of Geographic Information Studies
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    • v.17 no.2
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    • pp.1-14
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    • 2014
  • In this study, the change characteristics of urban spatial structure in Daegu were analyzed connecting with urban planning for efficient urban management. Urban development process from 1970 to 2010 in Daegu was analyzed utilizing Getis-Ord $G_i^*$ methodology, a spatial statistical method, and it was identified that Daegu was in the stage of disurbanization. However, as Daegu orients multi-nuclei city, it was difficult to explain the stage of urban development after disurbanization in 2000. Accordingly, to analyze detailed changes in spatial structure in multi-centric areas after 2000, population, land price and employment factor changes were analyzed using Bachi Measurement. According to analytical results, multi-centralization process has been continued in Daegu. Urban core area and Chilgok area showed spatial structure change into distribution process, Ansim area into concentration process, and Seongseo and Talseo area into concentration and distribution process. Therefore, urban planning considering the regional characteristics are needed for efficient urban management.

Analysis of the Impact on Changes in Residential Communities through Urban Regeneration with Art Programs - Focused on Cheong-ju Sajik 2-dong - (예술매개 도시재생 프로그램이 주거공동체 의식 변화에 미치는 영향력 분석 - 청주시 사직2동을 중심으로 -)

  • Choi, Min-Gyeong;Hwang, Hee-Yun;Kwon, Jeong-Ju
    • Journal of the Korean housing association
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    • v.23 no.4
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    • pp.69-76
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    • 2012
  • This study conducted an analysis of importance levels and also an AHP analysis based on the results of the monitoring (from Aug 2011 through Feb 2012) carried out in the Sajik 2-dong in the City of Cheong-ju. By quantitatively eliciting the effects that the urban regeneration projects that use art programs have on the changes in the perception of community housings and by analyzing the results of objective verification, this study was able to ascertain that local resident festivals had the greatest impacts on the change in the perception of community housings in the Sajik 2-dong in the City of Cheong-ju. This is deemed to be attributable to the fact that programs such as local resident festivals, in which various age groups participated, - amidst the unmitigated circumstance of Sajik 2-dong in the City of Cheong-ju (conflicts among the residents on account of redevelopment project) - exerted significant influences in the perceptional change of the community and in the resolution of conflicts.

Simulation of Changes in Nearby Thermal Environment According to Green Roof in Low-Rise Residential Area of Daegu (대구광역시 저층주거지역의 옥상녹화 조성에 따른 주변 열환경 변화 모의실험)

  • Kim, Dae-Wuk;Jung, Eung-Ho;Cha, Jae-Gyu
    • Journal of the Korean housing association
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    • v.24 no.3
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    • pp.45-53
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    • 2013
  • It is important to secure green spaces to solve the urban heat island phenomenon, which is among problems resulted by high-density developments in metropolitan areas. However, it is hard to secure such green spaces in established urban areas so Green Rooftop development approaches have recently been highlighted and introduced as a solution to the situation. The present study conducts a simulation on residential areas in urbanized regions to quantitatively evaluate the effects of green rooftop developments through a comparison of changes in the air temperatures before and after relevant development projects. According to the evaluation results, when the green roof top development is conducted in the available areas, the temperature is reduced by 0.14 degree. The extension of green project to the entire building showed the reduction of the temperature by 0.29 degree. Based on these results, it can be concluded that the green rooftop development is a practically solution for reducing the air temperature of urbanized areas.

A Study on the Aesthetic Preference for Rural Landscapes: urban and rural resident differences (도시 및 농촌거주자의 농촌경관선호도에 관한 연구)

  • 윤진옥;김유일;정기호
    • Journal of the Korean Institute of Landscape Architecture
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    • v.23 no.2
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    • pp.93-103
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    • 1995
  • The changes of rural landscape are currently spread everywhere and are rapidily being processed both in quality and in quantities of changes From such aspects, it is urgent to control the land scape change, and is required to know what is valued or preferred in rural landscape, This study was conducted to investigate preferences and differences of the responses between urban and rural residents to rural scenery. As a method, color-slide surrogates for rural landscape settings are shown to urban and rural residents, For a given 52 scenes of rural landscapes the respondents judged the familiarity, orality, and preference along a ten point scale. The following facts are found: 1) Refponses to certain types of landscape settings are influenced by the place of residence of the respondents. The urban residents highly rated natural components of the rural landscape. In contrast rural residents preferred the scenes with visible sign of development 2) The relations among the estimation of preference, familiarity and rurality in rural landscape were deeply correlated. When the rural lands(:ape is adequately ref resented as 'familiarity' or 'rurality' well the landscape is more preferred 3) It is found what is valued or preferred in rural landscape : Readjusted agricultural land, big tree, grassland hi dominated visually were preferred in rural landscape. The implication of this study is that successful planning of development or management in rural area will occur only when these different needs and values are acknowledged and accommodated.

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Citizens' Consciousness on Urban Changes in Large Cities in the 1990s(1) : A Comparative Study on Urban Social Sectors (1990년대 대도시의 변화에 관한 시민 의식 연구(1) : 사회 부문별 비교)

  • Choi, Byung-Doo;Lee, Kyung-Ja;Choi, Gum-Ae
    • Journal of the Korean association of regional geographers
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    • v.10 no.2
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    • pp.428-446
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    • 2004
  • This paper is to analyze citizens' consciousness on urban changes during the 1900s in the sectors of economy, politics and socio-culture of large cities in Korea, especially comparing them in Seoul, Daejeon, Daegu, and Kywangju. The items of questionnaire are drawn from theories on each sector of new urbanization of large city in Western countries, that is, that of post-Fordism, of urban governance, of post-modernism, and of sustainable city. Some major findings of this questionnaire analysis are as follows. First, on the change of large cities in general, citizens think that the sectors of spatial structure, and of socio-culture of the cities were changed more than those of urban economy and of urban politics. Secondly, in the sector of urban economy, citizens recognize that the obstructing factors of development, that is, the lack of regional capital and the absence of head-quarter of large firms, which seems to be resulted from uneven regional development in the previous periods were much more serious than others, while acknowledging the importance of high-tech industry. Thirdly, in the sector of urban politics, citizens think that the centralized structure of politics and of political parties was still problematic, while acknowledging the importance of entrepreneur mind of urban governor. Finally, in the sector of urban socio-culture, citizens emphasize the development of telecommunication, the popularization of private automobile and the increasing use of credit card, as three major factors which have exercised major impacts on the development of urban socio-culture.

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A Study on the Changes the Urban Space at Station Influenced Areas by the Open of Incheon Urban Railroad Line 1 (인천광역시 도시철도 1호선 개통에 따른 역세권 도시공간 변화 연구)

  • Ahn, Jung Geun;Park, Man Hee
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.1D
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    • pp.141-148
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    • 2011
  • City of Incheon opened rapid transit(urban railroad line 1) in 1999 in order to relieve traffic congestion on major arterials. This research analyzed urban space changes of each station influenced area by examining the changes of residents, industrial employees, and floor area ratios before and after the open of Incheon urban railroad line 1. Analysis of variance was applied to change of station influence area. This research found out that the types of central business and agricultural station influence area had been changed significantly after the open of urban railroad. However, the residential, semi-residential, and suburban type of station influence area had not been changed after the open of urban railroad. Thus, it is necessary to provide diverse facilities for inducing residents and employees to the station influence area of residential and semi-residential. Furthermore, the suburban type of station influence area which is difficult to develop naturally by the law of Green Belt is needed to develop station influence area simultaneously with the construction of a station building.