scholarly journals The Effect of Sky View Factor on Air temperature in High-rise Urban Residential Environments

2019 ◽  
Vol 6 (2) ◽  
pp. 42-51
Author(s):  
Golnar Baghaeipoor ◽  
◽  
Nazanin Nasrollahi ◽  
Atmosphere ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 353 ◽  
Author(s):  
Sytse Koopmans ◽  
Reinder Ronda ◽  
Gert-Jan Steeneveld ◽  
Albert Holtslag ◽  
Albert Klein Tank

In the Netherlands, there will be an urgent need for additional housing by the year 2040, which mainly has to be realized within the existing built environment rather than in the spatial extension of cities. In this data-driven study, we investigated the effects of different urban planning strategies on heat stress for the current climate and future climate scenarios (year 2050) for the urban agglomeration of The Hague. Heat stress is here expressed as the number of days exceeding minimum temperatures of 20 °C in a year. Thereto, we applied a diagnostic equation to determine the daily maximum urban heat island based on routine meteorological observations and straightforward urban morphological properties including the sky-view factor and the vegetation fraction. Moreover, we utilized the Royal Netherlands Meteorological Institute’s (KNMI) climate scenarios to transform present-day meteorological hourly time series into the future time series. The urban planning strategies differ in replacing low- and mid-rise buildings with high-rise buildings (which reduces the sky-view factor), and constructing buildings on green areas (which reduces the vegetation fraction). We found that, in most cases, the vegetation fraction is a more critical parameter than the sky-view factor to minimize the extra heat stress incurred when densifying the neighbourhood. This means that an urban planning strategy consisting of high-rise buildings and preserved green areas is often the best solution. Still, climate change will have a larger impact on heat stress for the year 2050 than the imposed urban densification.


Author(s):  
Wei Feng ◽  
Wei Ding ◽  
Yingdi Yin ◽  
Qixian Lin ◽  
Meng Zheng ◽  
...  

Rapid urbanization has caused environmental problems such as the urban heat island and air pollution, which are unfavorable to residents. Urban traditional blocks are facing the dual challenges of restoration and protection. This paper proposes adaptive transformation strategies for improving the microclimate of traditional areas. We selected Baxian’an Block in Xi’an city, simulated the air temperature and wind speed during summer and winter using ENVI-met, and studied the correlationship between morphological parameters (average building height, building density, enclosure degree, height fall, aspect ratio, and sky view factor) and air temperature and wind speed ratio. The case study revealed that the wind speed ratio of Baxian’an is relatively different in summer, reaching a maximum of 0.61, meaning that the ventilation capacity is significantly affected by the architectural form of the block. Finally, suggestions for the optimal design of the block’s form are provided: the building density should be less than 50%, the average building height should be more than 50 m, the enclosure degree should be less than 0.2, the height fall should be more than 41.7 m, and the sky view factor should be less than 0.5. This study can provide data and support for improving the planning and design standards of traditional residential areas.


2018 ◽  
Vol 40 ◽  
pp. 26
Author(s):  
Angela Fatima da Rocha ◽  
Ernany Paranaguá da Silva ◽  
Carlo Ralph de Musis ◽  
Marta Cristina de Albuquerque Nogueira

This article aims to analyse the sky view factor (SVF) in one of the hottest cities of the Brazilian Cerrado, and its correlation with thermal comfort in two urban sections with different characteristics, as well as the physiological equivalent temperature (PET) and predicted mean vote (PMV) indices, complemented by a characterisation in the frequency field for a 12-month cut-off in the same year of relative air temperature and humidity. The study area was located in the central region of Cuiabá, Mato Grosso, due to the presence of regions with high urbanisation indices and small parks; one section composed of afforested area and second section composed of varied buildings. To obtain the SVF, the Google Street View image database was used, from which fisheye images were reconstructed and the SVF was determined using  RayMan  software. The PET and PMV indices were determined for the morning, afternoon, and evening, with comfort in the morning and discomfort in the afternoon and evening. Traditional Morlet wavelets were plotted for time series of relative air temperature and humidity for the year 2015, which qualitatively demonstrated some of the dynamics of these micrometeorological variables for tropical Cerrado climate.


2021 ◽  
Author(s):  
Zian Wang ◽  
Guoan Tang ◽  
Guonian Lü ◽  
Cheng Ye ◽  
Fangzhuo Zhou ◽  
...  

2020 ◽  
Vol 76 (1) ◽  
pp. 44-52
Author(s):  
Shuh MATSUDA ◽  
Hisashi YOSHIKOSHI ◽  
Tomoyo SUZUKI ◽  
Yuuki OHTA ◽  
Ayaka CHIBA ◽  
...  

2015 ◽  
Vol 74 ◽  
pp. 279-286 ◽  
Author(s):  
J. Ramírez-Faz ◽  
R. López-Luque ◽  
F.J. Casares
Keyword(s):  

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