• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2000.11a
• /
• pp.203-204
• /
• 2000

도시협곡 내에서 형성되는 전형적인 유동장은 협곡내부에서 형성되는 회전류(vortex)이다(Berkowicz, 1998). Oke(1988)에 따르면 단면비가 큰 경우 (W/H＞2.5), 도시 협곡내 유동장은 isolated roughness flow, 단면비가 중간인 경우(1.538

• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.8
• /
• pp.852-858
• /
• 2005

Modeling techniques for air quality are useful tools in air quality management. Especially, the air quality in urban area is significantly influenced by local surroundings such as buildings and traffic. When considering the air quality in a street canyon, which is usually filmed by a series of consecutive buildings and a street, currently available air dispersion model have a number of limitations to predict the air quality properly. In this study, it is aimed to propose an empirical model for the air quality in urban street canyons. A series of wind tunnel tests, followed by statistical analysis, were conducted. In conclusion, it is found that a wide street canyon and a perpendicular external wind to the street canyon are beneficial to achieve an enhanced air quality in street canyon environment. The model prediction using the proposed model also shows reliable correlations to the wind tunnel test results.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2003.05b
• /
• pp.165-166
• /
• 2003

도심 도로변의 대기질은 주변의 고층 건물로 인한 거리 협곡으로 인하여 도시의 대기질에서 가장 빈번하게 기준을 초과하는 지역이다. 대부분의 대도시에서 고층 빌딩으로 구성된 도심 거리 협곡(urban street canyon)의 자동차에서 배출되는 대기오염물질은 운전자, 보행자, 도로변 작업자, 자동차 승객 등의 건강에 직접적으로 영향을 미칠 수 있다. 자동차 대기오염물질은 지표면에서 발생되기 때문에 거리 협곡은 배출원 인근의 대기오염물질 확산에 중요한 영향을 준다. 우선적으로, 거리 협곡은 협곡 상공에서 수직적인 혼합을 유도하게 된다. 둘째로, 거리 협곡의 형성은 협곡의 지형적 또는 물리적 경계 내의 오염물질을 정체시키게 되어, 협곡 상공으로 공기가 자유롭게 이동하여 오염물질을 수송하는 것을 지체시키는 경향이 있다. (중략)

• Korean Journal of Remote Sensing
• /
• v.30 no.6
• /
• pp.755-767
• /
• 2014

In this study, detailed air flow characteristics in an urban areas were analyzed using GIS data and a Computational Fluid Dynamics (CFD) model. For this, a building construction algorithm optimized for Geographic Information System (GIS) data with a vector format (Los Angeles region imagery acquisition consortium 2 geographic information system, LARIAC2 GIS) was used. In the LARIAC2 GIS data, building vertices were expressed as latitude and longitude. Using the model buildings constructed by the algorithm as the surface boundary data in the CFD model, we performed numerical simulations for two building-congested areas in Los Angeles using inflow information provided by California Air Resources Board. Comparing with the inflow, there was a marked difference in wind speed and direction within the target areas, which was mainly caused by the secondarily induced local circulations such as street-canyon vortices, horse-shoe vortices, and recirculation zones. In street canyons parallel to the inflow direction, wind speed increased due to a channeling effect and, in street canyons perpendicular to the inflow direction, vertically well developed vortices were induced. In front of a building, a horse-shoe vortex was developed near the surface and, behind a building, a recirculation zone was developed. Near the surface in the areas where the secondarily induced local circulations, wind speed remarkably increased. Overall, wind direction little (largely) changed at the areas where wind speed largely increased (decreased).

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 1997.04a
• /
• pp.89-90
• /
• 1997

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2004.11a
• /
• pp.80-81
• /
• 2004

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2006.10a
• /
• pp.97-98
• /
• 2006

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 1998.10a
• /
• pp.201-202
• /
• 1998

• Journal of the Korean Institute of Landscape Architecture
• /
• v.52 no.2
• /
• pp.21-38
• /
• 2024

This study aims to establish an efficient street green area to improve the urban thermal environment and enhance pedestrian thermal comfort. Specifically, This study identified parameters applicable to green space planning and design, analyzed thermal environment mitigation mechanisms for each parameter, and, based on these findings, proposed methods for tree species selection and planting in green space planning and design. To achieve this, 61 papers were selected through a four-stage process from both domestic and foreign sources. The selected papers were analyzed, and the following main results were derived: In open street canyons with high stress levels due to low aspect ratios and high sky view factors(SVF), broadleaf trees with wide crown widths, low trunk heights, high leaf area index(LAI), and high crown heights were found effective in reducing heat, thereby increasing the amount and quality of shade. In contrast, in deep and narrow street canyons with relatively low heat stress due to high aspect ratios and low SVF, broad-leaved trees with narrow crown widths, high trunks, low crown heights, and low LAI were effective in reducing heat by enhancing ventilation. This study can serve as fundamental data for establishing standards for street green spaces to improve the thermal environment of street canyons and enhance thermal comfort of pedestrians. Additionally, it can be valuable when selecting the location and prioritizing street green spaces. Moreover, it is anticipated to be a foundational resource for creating guidelines for green space planning and design in response to climate change.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.40 no.1
• /
• pp.12-22
• /
• 2012

In Seoul, skyscrapers are built in commercial zones known as residential-commercial complexes, which cause such environmental problems as urban heat islands(UHI) and air pollution. To investigate air temperature differences in areas near skyscrapers at Gangnam-gu, Seoul, South Korea, fixed air temperature observation and traverse observations were performed from March 16, 2008 to March 15, 2009. The annual mean air temperature at Tower Palace(TPL) was higher than that at Sookmyung Girls' High School(SMG) by $0.7^{\circ}C$, although the distance between the two observation positions is only 200m. The number of tropical nights at TPL was 13, while that at SMG was 5. The higher air temperature at TPL was due to a significantly lower sky view factor(SVF), which prevented long-wave radiation from emitting into the sky. The highest air temperature increases near TPL occurred on summer nights because of the high-electricity consumption value of $70.22Wh/m^2$ for the TPL block in August due to air conditioning for cooling. It is concluded that the warm air pocket centered on TPL.