scholarly journals The Ventilation Efficiency of Urban Built Intensity and Ventilation Path Identification: A Case Study of Wuhan

2021 ◽  
Vol 18 (21) ◽  
pp. 11684
Author(s):  
Jie Yin ◽  
Qingming Zhan ◽  
Muhammad Tayyab ◽  
Aqeela Zahra
Keyword(s):  
Wind Speed ◽  
Built Environment ◽  
Area Ratio ◽  
Speed Ratio ◽  
Building Density ◽  
Building Height ◽  
Floor Area ◽  
Intensity Index ◽  
Floor Area Ratio ◽  
Ventilation Efficiency

Urban ventilation is being hampered by rough surfaces in dense urban areas, and the microclimate and air quality of the urban built environment are not ideal. Identifying urban ventilation paths is helpful to save energy, reduce emissions, and improve the urban ecological environment. Wuhan is the capital city of Hubei, and it has a high urban built intensity and hot summers. Taking Wuhan city, with a size of 35 km ×50 km, as an example, the built environment was divided into grids of 100 m × 100 m and included the building density, floor area ratio, and average building height. The ventilation mechanism of the urban built intensity index has previously been explained. The decrease in building density is not the sole factor causing an increase in wind speed; the enclosure and width of the ventilation path and the height of the front building are also influential. Twelve urban built units were selected for CFD numerical simulation. The ventilation efficiency of each grid was evaluated by calculating the wind speed ratio, maximum wind speed, average wind speed, and area ratio of strong wind. The relationship between the urban built intensity index and ventilation efficiency index was established using the factor analysis method and the Pearson correlation coefficient; building density and average building height are the most critical indexes of ventilation potential. In addition, the layout of the building also has an important impact on ventilation. A suitable built environment is that in which the building density is less than 30%, the average building height is greater than 15 m, and the floor area ratio is greater than 1.5. The urban built intensity map was weighted to identify urban ventilation paths. The paper provides a quantitative reference for scientific planning and design of the urban spatial form to improve ventilation.

scholarly journals Optimization Strategy of Traditional Block Form Based on Field Investigation—A Case Study of Xi’an Baxian’an, China

2021 ◽  
Vol 18 (20) ◽  
pp. 10895
Author(s):  
Wei Feng ◽  
Wei Ding ◽  
Yingdi Yin ◽  
Qixian Lin ◽  
Meng Zheng ◽  
...  
Keyword(s):  
Wind Speed ◽  
Air Temperature ◽  
Speed Ratio ◽  
View Factor ◽  
Rapid Urbanization ◽  
Architectural Form ◽  
Building Density ◽  
Building Height ◽  
Sky View Factor

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.

scholarly journals Fusion of Remote Sensing and Internet Data to Calculate Urban Floor Area Ratio

2019 ◽  
Vol 11 (12) ◽  
pp. 3382
Author(s):  
Xiaoyong Zhang ◽  
Zhengchao Chen ◽  
Yuemin Yue ◽  
Xiangkun Qi ◽  
Charlie H. Zhang
Keyword(s):  
Remote Sensing ◽  
Three Dimensional ◽  
Remote Sensing Data ◽  
Quantitative Relationship ◽  
Area Ratio ◽  
Building Density ◽  
Sensing Data ◽  
Floor Area ◽  
Floor Area Ratio ◽  
Map Data

The floor area ratio is a comprehensive index that plays an important role in urban planning and sustainable development. Remote sensing data are widely used in floor area ratio calculations because they can produce both two-dimensional planar and three-dimensional stereo information on buildings. However, remote sensing is not adequate for calculating the number of floors in a building. In this paper, a simple and practical pixel-level model is established through defining a quantitative relationship among the floor area ratio, building density, and average number of floors (ANF). The floor area ratios are calculated by combining remote sensing data with publicly available Internet data. It incorporates supplemental map data and street-level views from Internet maps to confirm building types and the number of floors, thereby enabling more-accurate floor area ratio calculations. The proposed method is tested in the Tiantongyuan neighborhood, Changping District, Beijing, and the results show that it can accurately approximate the number of floors in buildings. Inaccuracies in the value of the floor area ratio were found to be primarily due to the uncertainties in building density calculations. After performing systematic error correction, the building density (BD) and floor area ratio were each calculated with the relative accuracy exceeding 90%. Moreover, the experiments verified that the fusion of internet map data with remote sensing data has innate advantages for floor area ratio calculations.

Research on 3D Simulation of Regulatory Plan with GIS and Modeling Incubator

2013 ◽  
Vol 336-338 ◽  
pp. 1412-1415
Author(s):  
Cheng Wu Wang ◽  
Zhi Hao Mao ◽  
Jia Qi Lei
Keyword(s):  
City Planning ◽  
Area Ratio ◽  
3D Simulation ◽  
Gis Technology ◽  
Floor Area ◽  
Floor Area Ratio ◽  
Virtual City ◽  
Regulatory Plan ◽  
Aided Design

GIS technology has been applied in city planning management and virtual city. It still hasnt got more substantive achievements on aided design of regulatory plan. The notion of Modeling-Incubator has been advanced and integrated with GIS, which is the key resolution and method to 3D simulation of regulatory plan indexes, such as building coverage, floor area ratio, building interval etc. This resolution will be applied in regulatory plan assessment.

Estimating Floor Area Ratio of Urban Buildings Based on the QuickBird Image

2012 ◽  
Vol 450-451 ◽  
pp. 614-617
Author(s):  
Yi Zhou Wu ◽  
Bo Li
Keyword(s):  
Scientific Basis ◽  
Area Ratio ◽  
Administrative District ◽  
Policy Makers ◽  
Floor Area ◽  
Floor Area Ratio ◽  
Urban Economic Development ◽  
Urban Buildings ◽  
Object Based ◽  
Pca Transform

Floor area ratio (FAR) is fundamentally important for urban economic development and for urban design, planning and management. This paper tried to enhance the texture information of the QuickBird image by using HIS and PCA transform methods in Yiwu city as a case study. An object-based method was proposed to process the enhanced QuickBird image for the shadow of buildings and building object areas, and the building heights were accurately calculated based on the shadow of buildings. The building object areas and heights were integrated with an administrative district map in Yiwu city to estimate FAR. Tests with this above method demonstrated excellent accuracy in terms of FAR estimation. The high spatial resolution images have great potential in quickly and accurately estimating FAR, providing a scientific basis to policy makers and urban planners.

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