• Title/Summary/Keyword: large urban region

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A Study of the Urban Heat Island in Seoul using Local Analysis System (지역규모 분석 모델을 이용한 서울 도시열섬 특성 연구)

  • Chun, Ji Min;Lee, Seon-Yong;Kim, Kyu Rang;Choi, Young-Jean
    • Journal of Korean Society for Atmospheric Environment
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    • v.30 no.2
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    • pp.119-127
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    • 2014
  • A very high resolution weather analysis system (VHRAS) of 50 m horizontal resolution is established based on LAPS. VHRAS utilizes the 3 hourly forecast data of the Unified Model (UM) of the Korea Meteorological Administration (KMA) with the horizontal resolution of 12 km as initial guess fields. The analysis system ingests the automatic weather station (AWS) data as input observations. The analysis system operates every hour for Seoul, Korea region in real time basis. It takes less than 10 minutes for one analysis cycle. The size of grid of the analysis domain is $800{\times}660$, respectively. The analysis results from December 2010 to February 2011 showed that the mean biases of temperature, maximum and minimum temperature were -0.07, 1.6, $0.2^{\circ}C$, respectively. The temperature in the central part of the city revealed relatively higher value than that of the surrounding mountainous areas, which showed a heat island feature. The heat island appears in zonal direction since the central city region is developed along a large river. Along the heat island, the eastern region was warmer than the western region. The warmer temperature in the western part of the heat island was caused by anthropogenic heat change in conjunction with the change of land use. This system will provide more reliable weather data and information in Seoul.

T-START: Time, Status and Region Aware Taxi Mobility Model for Metropolis

  • Wang, Haiquan;Lei, Shuo;Wu, Binglin;Li, Yilin;Du, Bowen
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.7
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    • pp.3018-3040
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    • 2018
  • The mobility model is one of the most important factors that impacts the evaluation of any transportation vehicular networking protocols via simulations. However, to obtain a realistic mobility model in the dynamic urban environment is a very challenging task. Several studies extract mobility models from large-scale real data sets (mostly taxi GPS data) in recent years, but they do not consider the statuses of taxi, which is an important factor affected taxi's mobility. In this paper, we discover three simple observations related to the taxi statuses via mining of real taxi trajectories: (1) the behavior of taxi will be influenced by the statuses, (2) the macroscopic movement is related with different geographic features in corresponding status, and (3) the taxi load/drop events are varied with time period. Based on these three observations, a novel taxi mobility model (T-START) is proposed with respect to taxi statuses, geographic region and time period. The simulation results illustrate that proposed mobility model has a good approximation with reality in trajectory samples and distribution of nodes in four typical time periods.

Analysis of Streetscape Image using Landscape Adjectives in Rural Town - Focused on 10 Rural Towns near Gwangju Metropolitan City - (경관형용사를 이용한 면소재지 중심가로 이미지 분석 - 광주광역시에 인접한 10개 면소재지 중심가로를 대상으로 -)

  • Kim, Young Tae;Cho, Tong Buhm
    • Journal of Korean Society of Rural Planning
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    • v.28 no.3
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    • pp.25-33
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    • 2022
  • Due to the standardized urban development since the industrial era, many urban spaces have experienced non-placeness. Recently, although interest in urban landscape, history, and cultural elements has been increasing, landscape management and control measures are being implemented mainly in large cities due to the low status of rural areas in the country. From this point of view, this study tried to lay the foundation for basic research in related fields by classifying the characteristics and types of streetscapes located near large cities, and to suggest directions that should be considered when managing streetscapes in the future. As a result of the analysis of landscape adjectives, the village felt secluded due to the low density compared to the city street overall, but it did not have a unique image of the region. Three factors were derived through factor analysis, and preference was affected in the order of aesthetic, regularity, and uniqueness. In addition, the research site was classified into three types through cluster analysis, and it was confirmed that the differences by type were due to aesthetics and naturalness. On the other hand, the uniqueness is generally low in all regions, so it seems that fundamental countermeasures are needed.

The Effect of Building Morphology on Sea Breeze Penetration over the Kanto Plain - Analysis of Mean Kinetic Energy Balance of Moving Control Volume along Sea Breeze -

  • Sato, Taiki;Ooka, Ryozo;Murakami, Shuzo
    • International Journal of High-Rise Buildings
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    • v.1 no.2
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    • pp.73-80
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    • 2012
  • In order to use sea breezes to counter the heat island phenomena, i.e. to promote urban ventilation, it is necessary to clarify the effect of building morphology and height on large-scale wind fields. In this study, the sea breeze in the vicinity of the Kanto Plain in Japan is simulated using a mesoscale meteorological model incorporating an urban canopy model, and the inland penetration of sea breezes is accurately reproduced. Additionally, a mean kinetic energy balance within a domain (Control Volume; CV) moving along the sea breeze is analysed. From the results, it is clarified that the sea breeze is interrupted by the resistance and turbulence caused by buildings at the centre of Tokyo. The interruption effect is increased in accordance with the height of these buildings. On the other hand, adverse pressure gradients interrupt in the internal region.

A Study on the Current Status and Challenge of Core Project in Urban Regeneration -Focused on the Type of Central Commercial District- (도시재생사업에서 핵심사업의 추진 현황과 과제 -중심시가지형 사업 추진 사례를 중심으로-)

  • Kim, Young-Hwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.2
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    • pp.819-828
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    • 2021
  • In urban regeneration projects, the core projects define the characteristics of the project site and contribute to the highest project cost and drive the project forward. The purpose of this study was to identify the current status and characteristics of the project as a priming project for urban regeneration and to seek desirable alternatives in the future project process. For this purpose, the case of urban regeneration projects in the Chungcheong region was targeted. The results showed that the core projects for each case consisted mainly of projects to develop physical facilities on a relatively large scale. Securing large-scale complex base space and constructing public parking lots are planned as key projects. In addition, based on the cost composition of the priming project, the core project accounted for approximately 80 % of the total project, and the project cost between linked projects does not appear to be relatively well linked in both public and private investment sectors. These findings are expected to help promote substantial urban regeneration projects and enhance efficiency by using them as basic data for urban regeneration projects in the future.

The Role and Directions of Korean Urban Development Cooperation: A Review of Colombian Planning Systems and Case Studies of Urban Development Projects (콜롬비아 도시계획 제도와 도시개발사업 사례 분석을 중심으로 살펴본 한국 도시개발 협력 역할과 과제)

  • Choi, Junyoung
    • Land and Housing Review
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    • v.12 no.4
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    • pp.15-30
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    • 2021
  • Korean urban development cooperation is gradually expanding into Latin America and the Caribbean (LAC) region, but strategies to encourage domestic market players to participate are insufficient. This paper investigated the Colombian urban planning system, urban development projects, and Korean projects in Colombia, which leads to implications for international cooperation in LAC. This research, first, compares the national and regional urban planning systems of Colombian major cities, Bogotá and Medellín. Second, case studies are carried out with a land readjustment project, a Macro project for large-scale public rental housing supply, and urban development cooperation between Korea and Colombia. By doing so, the role and the directions for Korean urban development cooperation with LAC such as Colombia are discussed and proposed. The findings suggest, first, aid projects through Official Development Assistance (ODA) should establish urban networks in recipient countries. Second, it is necessary to understand the financing structure for urban development cooperation projects that are different from infrastructure projects. Third, the successful case of urban development cooperation should be demonstrated by making the development period and size optimal and manageable.

Analyzing the Cooling Effect of Urban Green Areas by Using the Multiple Observation Network in the Seonjeongneung Region of Seoul, Korea (최근 2년간 서울 선정릉 지역의 복합센서 관측망을 활용한 녹지 냉각효과 분석)

  • Kim, Geun-Hoi;Lee, Young-Gon;Lee, Dae-Geun;Kim, Baek-Jo
    • Journal of Environmental Science International
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    • v.25 no.11
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    • pp.1475-1484
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    • 2016
  • To analyze the cooling effect of urban green areas, we conducted micrometeorological measurements in these areas and their surroundings in Seoul, Korea. From the average hourly temperature measurements through each month for the last two years (March 2013 to February 2015), we found that the maximum temperature difference between urban and green areas was about $2.9^{\circ}C$ at 16:00 LST in summer, and the minimum was about $1.7^{\circ}C$ at 22:00 LST in winter. In summer, the temperature difference was the largest during the day, rather than at night, due mainly to shading by the tree canopy. The specific humidity difference between the two areas was about $1.5g\;kg^{-1}$ in summer, and this decreased in the winter. The specific humidity difference between urban and green areas in summer is relatively large during the day, due to the higher evapotranspiration level of biologically active plants.

Analysis and Comparison of Labor Market Stability by Business Categories in Urban and Rural Areas : Industrial Group, Employment Size, and Survival Duration (도시 및 농촌지역 사업체 유형별 노동시장 안정성 비교분석: 산업군, 종사자규모 및 존속기간별 유형을 중심으로)

  • Lee, Jemyung
    • Journal of Korean Society of Rural Planning
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    • v.23 no.1
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    • pp.97-112
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    • 2017
  • Stability of labor market in rural areas was analyzed in this paper with categories of industrial group, employment scale, surviving period, and founder group. The stability of each classified labor market was compared with each other to figure out the stable business class and the unstable class in rural areas. The results of rural areas were compared with those of urban areas. The stability was analyzed with average and coefficient of variation (C.V.) of annual total employees' change rates. It was revealed that labor market of 'primary industry', including agriculture, is unstable. Especially, labor market of 'mid-size' and 'primary industry' businesses founded as 'incorporated company' in rural areas is vulnerable. While labor market of 'large-size' is proved to be unstable, it is confirmed that 'small-size' or 'mid-size', and 'over-ten-year survived' businesses have positive contribution to the stable labor market in rural and urban areas. The results show that the stability of labor market is different in each category of business and in each region of rural or urban area. It is expected that the results can be utilized for the regional development policies, of labor and industry part.

A Study of the Characteristics of Input Boundary Conditions for the Prediction of Urban Air Flow based on Fluid Dynamics (유체 역학 기반 도시 기류장 예측을 위한 입력 경계 바람장 특성 연구)

  • Lee, Tae-Jin;Lee, Soon-Hwan;Lee, Hwawoon
    • Journal of Environmental Science International
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    • v.25 no.7
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    • pp.1017-1028
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    • 2016
  • Wind information is one of the major inputs for the prediction of urban air flow using computational fluid dynamic (CFD) models. Therefore, the numerical characteristics of the wind data formed at their mother domains should be clarified to predict the urban air flow more precisely. In this study, the formation characteristics of the wind data in the Seoul region were used as the inlet wind information for a CFD based simulation and were analyzed using numerical weather prediction models for weather research and forecasting (WRF). Because air flow over the central part of the Korean peninsula is often controlled not only by synoptic scale westerly winds but also by the westerly sea breeze induced from the Yellow Sea, the westerly wind often dominates the entire Seoul region. Although simulations of wind speed and air temperature gave results that were slightly high and low, respectively, their temporal variation patterns agreed well with the observations. In the analysis of the vertical cross section, the variation of wind speed along the western boundary of Seoul is simpler in a large domain with the highest horizontal resolution as compared to a small domain with the same resolution. A strong convergence of the sea breeze due to precise topography leads to the simplification of the wind pattern. The same tendency was shown in the average vertical profiles of the wind speed. The difference in the simulated wind pattern of two different domains is greater during the night than in the daytime because of atmospheric stability and topographically induced mesoscale forcing.

Characteristics of Changes in Air and Road Temperatures Induced by Environmental Conditions in the Urban Region of Seoul Through an Intensive Observing Period (IOP) of Heatwaves in the Summer of 2023 (2023년 여름철 폭염 집중관측을 통한 서울 도심환경 조건에 따른 기온 및 노면 온도의 변화 특성)

  • Sung-Joon Na;Sang-Dae Han;Je-Won Kim;Moon-Su Park;Baek-Jo Kim
    • Journal of Environmental Science International
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    • v.33 no.1
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    • pp.75-85
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    • 2024
  • An intensive observing period (IOP) of heatwaves in the urban region of Seoul in the summer of 2023 was carried out to understand the changes in air temperature and road temperature induced by environmental conditions. The temperature observed at eight points with different urban environmental conditions was compared with the temperature by the KMA/AWS to analyze the characteristics of change in air temperature by height and the change in road temperature according to environmental conditions and road sprinkler. The comparison of the average temperature observed in different urban environmental conditions with the temperature observed at KMA/AWS showed that the air temperature in asphalt and open space sites was 0.7 to 2.3℃ higher and that the one in bus stops was 0.9 to 2.3℃ higher. In terms of temperature deviations depending on residential type, the temperature in highly populated areas was about 0.1 to 0.8℃ higher than that of apartment complexes. In addition, regardless of the size of a park, the temperature in the park was lower than the temperature in dense housing areas and apartment complexes. In asphalt and residential areas, the road temperature was higher than the temperature at a height of 150 cm, Conversely, road temperature was lower than air temperature in a shaded shelter and large park. In addition, after spraying a surface road, the road temperature immediately dropped by about 3 to 4℃; however, after about 20 minutes, it rose again to the previous road temperature. This change in road temperature appeared only for the temperature of 30 cm height.