• Title/Summary/Keyword: the urban environment

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Status of particulate matter pollution in urban railway environments (도시철도 환경의 미세먼지 오염 현황)

  • Kim, Jong Bum;Lee, Seung-Bok;Bae, Gwi-Nam
    • Journal of odor and indoor environment
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    • v.17 no.4
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    • pp.303-314
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    • 2018
  • 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.

Analysis on the Types of Benefits of Gardens in Urban Areas: Comparison of Korea and Overseas Cases

  • Park, Jiwon;Jeong, Miae
    • Journal of People, Plants, and Environment
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    • v.23 no.6
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    • pp.667-681
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    • 2020
  • Background and objective: Recently, there has been an increasing need for relaxation and familiarity with nature in residential and living spaces faced daily by urban residents, leading to a growing social interest in urban gardens. The aim of this study was to determine how gardens in a city provide physical and social benefits, comparing cases in Korea and overseas. Methods: We used the keywords "garden" and "city" for Korea, and "urban," "garden," and "green" for overseas. We then determined the Korean and overseas research trends in urban gardens by analyzing 63 Korean and 90 overseas articles deemed suitable for this study. Results: As to the types of urban gardens, the most significant type was community gardens, both in Korea and overseas (30.2% and 48.6%, respectively), followed by rooftop gardens in Korea (22.2%) and kitchen gardens overseas (22.2%). Due to the narrow and complex urban structure in Korea, people focus on using rooftop, wall, and alley spaces, and tend to arrange container-type flexible gardens. Overseas there has been a focus on promoting health and reducing food inequality through allotment and kitchen gardens, and a tendency to use a larger area as a fixed form than Korea. In addition, it was found that gardens in urban areas had a positive effect on urban biodiversity. Conclusion: To sum up, gardens in Korea are close to living spaces, and gardens overseas influence the ecosystem with an emphasis on food production. Therefore, creating urban gardens is a method of urban regeneration with a high utility that goes beyond mere food production, both in Korea and overseas, providing comprehensive benefits for the environment (37.73%) and society (62.27%). As such, continuous research on this area of study is needed to create policy guidelines for Korea.

Numerical Study on the Air Cooling Effect due to Increased Albedo in Urban Area (알베도 증가에 따른 도시 기온 하강 효과에 관한 수치연구)

  • Lee, Hyun-Ju;Lee, Kwi-Ok;Lee, Soon-Hwan;Lee, Hwa-Woon
    • Journal of Korean Society for Atmospheric Environment
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    • v.24 no.4
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    • pp.383-392
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    • 2008
  • In order to clarify the influence of the change of urban surface albedo on mesoscale meteorological factors during the summertime, numerical experiments with various albedo of urban surface were carried out. Numerical model used in this study is PSU/NCAR MM5 V3.6. As a result of the numerical simulation intended of Busan assumed the increase of albedo of roofs, buildings, or roads, the increase of albedo can make decrease radiation effect of surface, so that it caused drops in ambient air temperature from $0.5^{\circ}C$ to $1^{\circ}C$ on the average, and the downtown of Busan formed along the trough presented a substantial drop in ambient air temperature about $1.5^{\circ}C$. Modeling studies suggest the increased surface albedo in urban area can reduce surface and air temperatures near the ground and affect related meteorological parameters such as winds and the depth of the mixed boundary layer.

Urban Sprawl prediction in 2030 using decision tree (의사결정나무를 활용한 2030년 도시 확장 예측)

  • Kim, Geun-Han;Choi, Hee-Sun;Kim, Dong-Beom;Jung, Yee-Rim;Jin, Dae-Yong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.23 no.6
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    • pp.125-135
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    • 2020
  • The uncontrolled urban expansion causes various social, economic problems and natural/environmental problems. Therefore, it is necessary to forecast urban expansion by identifying various factors related to urban expansion. This study aims to forecast it using a decision tree that is widely used in various areas. The study used geographic data such as the area of use, geographical data like elevation and slope, the environmental conservation value assessment map, and population density data for 2006 and 2018. It extracted the new urban expansion areas by comparing the residential, industrial, and commercial zones of the zoning in 2006 and 2018 and derived a decision tree using the 2006 data as independent variables. It is intended to forecast urban expansion in 2030 by applying the data for 2018 to the derived decision tree. The analysis result confirmed that the distance from the green area, the elevation, the grade of the environmental conservation value assessment map, and the distance from the industrial area were important factors in forecasting the urban area expansion. The AUC of 0.95051 showed excellent explanatory power in the ROC analysis performed to verify the accuracy. However, the forecast of the urban area expansion for 2018 using the decision tree was 15,459.98㎢, which was significantly different from the actual urban area of 4,144.93㎢ for 2018. Since many regions use decision tree to forecast urban expansion, they can be useful for identifying which factors affect urban expansion, although they are not suitable for forecasting the expansion of urban region in detail. Identifying such important factors for urban expansion is expected to provide information that can be used in future land, urban, and environmental planning.

Phytoremediation of Urban Air Pollution

  • Fang, Qin;Wang, Yun;Jin, Jie
    • Journal of Urban Science
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    • v.8 no.2
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    • pp.35-39
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    • 2019
  • With the rapid progress of society and economic growth, more and more factories are put into construction, although to a certain extent to promote the development of our country's economy, but the waste gas and waste water produce also harm the environment.Among them, air pollution causes great damage to the environment and harms human health.In order to protect people's safety and health, people began to look for some measures to control air pollution, one of the most effective way is to plant more green plants, using plants for air purification.

A Study of Vegetation and Soil Characteristic of Urban Forest in Daejeon City (대전시 도시숲의 식생 및 토양특성에 관한 연구)

  • Kim, Dong-Il;Park, Gwan-Soo;Kim, Gil-Nam;Kim, Hyoun-Sook;Lee, Hang-Goo;Park, Beom-Hwan;Lee, Sang-Jin;Kang, Kil-Nam
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.14 no.2
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    • pp.11-20
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    • 2011
  • This study was conducted to suggest appropriate methods for management of urban forest after investigating the present condition and problems of urban forests by analyzing vegetation and soil properties in urban forests in the Daejeon. On the basis of our research, Pinus rigida dominate Gyejoksan and Bomunsan. Pinus densiflora dominate Wolpyeong park and Quercus acutissima dominate Namsun park. On the basis of our result of analysis of soil chemical properties, all investigated areas have low pHs, available phosphates and exchangeable cations. They indicate that the soil of those areas have been acidifying progressively. Soil hardness measurements were conducted to know the conditions of trampled soils and the results of them show that soil hardness in Namsun park was higher than the others. This indicates that human interference affect the health of the urban forest.

Potentiality of urban forest roads as an environment for enhancing physical fitness (건강증진 환경 조성을 위한 도시근교 임도의 활용 가능성)

  • Jeon, Yong-Jun;Choi, Yeon-ho;Kim, Myeong-Jun;Lee, Joon-Woo;Park, Bum-Jin
    • Korean Journal of Agricultural Science
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    • v.38 no.1
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    • pp.109-113
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    • 2011
  • The purpose of this study was to examine the potentiality of urban forest roads as an environment for enhancing physical fitness. Six male university students participated in the study as subjects. The subjects walked on an urban forest road for 30 minutes. As a control experiment, they also walked on a national park trail for 30 minutes. Subjects' heart rates were monitored during the walks to calculate the ratio of the average time their heart rates were within the target range (from 60% to 80% of the maximal heart rate) for Enhancing Physical Fitness. After the walks, images of the spaces were analyzed using the semantic differential (SD) method. During the walk on the urban forest road, subjects' heart rates were within the target range 63.3% of the time, and lower than the target range 36.7% of the time. During the control experiment on the national park trail, subjects' heart rates were within the target range only 23.3% of the time, and higher than the target range 76.7% of the time. From the spatial perception evaluation using the SD method, subjects' comfortable and natural feelings when they were on the national park trail were significantly greater than when they were on the urban forest trail, but there were no differences in terms of other SD descriptors, such as friendliness and likeability. The results of our study indicate that the urban forest road provides a good environment for walking to enhance physical fitness. Although not as close to nature as national park trails, urban forest roads offer similar natural environments and have a high potentiality for serving as leisure spaces for urban residents who seek physical activities.

Type Drive Analysis of Urban Water Security Factors

  • Gong, Li;Wang, Hong;Jin, Chunling;Lu, Lili;Ma, Menghan
    • Journal of Information Processing Systems
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    • v.16 no.4
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    • pp.784-794
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    • 2020
  • In order to effectively evaluate the urban water security, the study investigates a novel system to assess factors that impact urban water security and builds an urban water poverty evaluation index system. Based on the contribution rates of Resource, Access, Capacity, Use, and Environment, the study adopts the Water Poverty Index (WPI) model to evaluate the water poverty levels of 14 cities in Gansu during 2011-2018 and uses the least variance method to evaluate water poverty space drive types. The case study results show that the water poverty space drive types of 14 cites fall into four categories. The first category is the dual factor dominant type driven by environment and resources, which includes Lanzhou, Qingyang, Jiuquan, and Jiayuguan. The second category is the three-factor dominant type driven by Access, Use, and Capability, which includes Longnan, Linxia, and Gannan. The third category is the four-factor dominant type driven by Resource, Access, Capability, and Environment, which includes Jinchang, Pingliang, Wuwei, Baiyin, and Zhangye. The fourth category is the five-factor dominant type, which includes Tianshui and Dingxi. The driven types impacting the urban water security factors reflected by the WPI and its model are clear and accurate. The divisions of the urban water security level supply a reliable theoretical and numerical basis for an urban water security early warning mechanism.

Hydrologic Cycle Simulation of Urban River for Rehabilitation of Water Environment (II) - Dorimcheon Basin - (물 환경 건전화를 위한 도시하천의 물 순환 모의 (II) - 도림천 유역 -)

  • Lee, Sang-Ho;Lee, Jung-Min
    • Journal of Korean Society on Water Environment
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    • v.22 no.5
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    • pp.815-823
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    • 2006
  • The hydrologic cycle in urban catchment has been changed due to the expansion of impervious area by rapid urban development. In this study, the SWMM 5 (Storm Water Management Model 5) model was used to simulate the hydrologic cycle of the Dorimcheon catchment which suffers from the distorted hydrologic cycle as a typical urban catchment. This study compare continuous simulation of urban runoff combining the channel and sewer system with that of channel only in the Dorimcheon catchment. Continuous simulations of urban runoff were performed for the upstream basin of Dorim bridge. The urban impervious regions were processed by the land use analysis from LANDSAT_TM images. It was performed from 1975 to 2000 for every five years. Surface, groundwater and wastewater runoffs were additionally included in the simulations one at a time. Such simulations made it possible to evaluate those components quantitatively. The result of continuous simulation of urban runoff combining the channel and sewer system is that peak flow and recession are well simulated. The analysis results of urbanization effect on runoff are as follows: the surface runoff in 2000 increases to 64% of the whole precipitation whereas the surface runoff in 1975 amounts to 46% of the precipitation; the groundwater runoff in 2000 amounts to 6% and shows 8% decrease during the period from 1975 to 2000.

The Analysis of User's Degree on Landscape Satisfaction Factors for Pedestrian Road -Case Study of Bun-Dang New Town- (보행자 전용도로의 이용자 경관만족 요인분석 -분당 신도시를 중심으로-)

  • Kim, Dae-Hyun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.4 no.2
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    • pp.1-10
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    • 2001
  • The purpose of this study was to investigate factors and variables which have significant effects on landscape satisfaction of urban pedestrian road in Bun-dang new town and to suggest basic information for urban pedestrian road design. These works consist of two phase. First, we tested the Hye-Cheon college students' degree of landscape satisfaction for 37 spots of urban pedestrian road and then selected 10 sports slide by the Sturges' formula. Second, we analysed factors and variables on landscape satisfaction of urban pedestrian road using the semantic differential scale method and then processed using descriptive analysis, factor analysis and multiple linear regression analysis. The major findings of this study can be summarized as follows; 1) The difference of landscape adjectives between the highest score of landscape satisfaction slide and the lowest score landscape satisfaction slide were diversity of vegetation, plenty of the shade of a tree, naturalness and cleanness. 2) Diversity of vegetation, width of road, freedom of danger and diversity of environment can be significant variables of major effects on landscape satisfaction of urban pedestrian road by using the multiple linear regression analysis. 3) Factors covering the landscape satisfaction of urban pedestrian road have been found to be Environment of urban pedestrian road and Constitution of urban pedestrian road. By using the Varimaxs' rotation factor analysis for the number of factors' cumulative percentage has been obtained as 64%. 4) Environment of urban pedestrian road and Constitution of urban pedestrian road can be significant factors of major effects on landscape satisfaction of urban pedestrian road by using the multiple linear regression analysis. In conclusion, the landscape satisfaction factors and variables of urban pedestrian road need to be considered in plan or design the urban pedestrian road.

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