scholarly journals Experimental Analysis of the Influence of Urban Morphological Indices on the Urban Thermal Environment of Zhengzhou, China

Atmosphere ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1058
Author(s):  
Xuefan Zhou ◽  
Hong Chen

Summer extreme high-temperatures occur frequently in large cities; urban spatial form is the primary factor affecting the urban thermal environment. Thus, planning and arranging urban spaces is a key approach to regulating urban microclimates. Studies into how urban spatial forms influence the formation of urban microclimates have been carried out for multiple cities in warm and hot regions; however, few studies of this kind have been carried out for cities in cold regions. In this study, we analyze Zhengzhou, a city located in a cold region of China, using summer 2017 measurement data to determine why high temperatures develop in cold areas. We investigated how temperature and humidity vary during the morning, at noon, and in the evening given different land use properties (commercial and residential) and different spatial forms (building height, building density, green coverage rate, and plot ratio); we then studied the correlation between urban spatial form and the urban thermal environment. Our research results indicate that the commercial district’s thermal microclimate was related to PR and BH in the afternoon and GCR in the morning and at night. In the residential district, the key urban morphology factors related to its thermal microclimates were BD, PR, and GCR during almost the whole day.

2020 ◽  
Vol 12 (18) ◽  
pp. 7663
Author(s):  
Sihong Du ◽  
Yanxia Li ◽  
Chao Wang ◽  
Zhichao Tian ◽  
Yongdong Lu ◽  
...  

The problem of the urban thermal environment is becoming increasingly noticeable in the process of modern urban development. The temperature patterns in central business districts can be more complicated due to the heterogeneous urban spaces and diverse building forms, which need more cross-scale research. This study investigated the correlation between air temperature and urban morphology in a heterogeneous urban district in northeastern China. The thermal environment of the studied district in the summertime was simulated by ENVI-met. A total of 12 morphological indicators were selected to describe the geometric features of the studied district. Curve estimation was employed to quantify the correlation between air temperature and morphological indicators. The results indicate different effects of the morphological indicators of the air temperature on different scales. On a mesoscale, the compactness (Com), building footprint ratio (BFR), enclosure degree (ED) and total height to total floor area ratio (HA) had a significant correlation with the air temperature. On a microscale, only the BFR and ED had relatively steady correlations with the air temperature. The correlation between air temperature and morphological indicators could be influenced by the heterogeneity of the urban morphology, including the diversity of the heights and footprints of buildings and the irregularity of building horizontal arrangement.


2021 ◽  
pp. 108224
Author(s):  
Xuan Chen ◽  
Jiachuan Yang ◽  
Rui Zhu ◽  
Man Sing Wong ◽  
Chao Ren

2017 ◽  
Vol 122 ◽  
pp. 967-972 ◽  
Author(s):  
Takashi Inoue ◽  
Taizo Shimo ◽  
Masayuki Ichinose ◽  
Kozo Takase ◽  
Tsutomu Nagahama

Atmosphere ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 402 ◽  
Author(s):  
Xiaoxue Wang ◽  
Yuguo Li ◽  
Xinyan Yang ◽  
Pak Chan ◽  
Janet Nichol ◽  
...  

The street thermal environment is important for thermal comfort, urban climate and pollutant dispersion. A 24-h vehicle traverse study was conducted over the Kowloon Peninsula of Hong Kong in summer, with each measurement period consisting of 2–3 full days. The data covered a total of 158 loops in 198 h along the route on sunny days. The measured data were averaged by three methods (direct average, FFT filter and interpolated by the piecewise cubic Hermite interpolation). The average street air temperatures were found to be 1–3 °C higher than those recorded at nearby fixed weather stations. The street warming phenomenon observed in the study has substantial implications as usually urban heat island (UHI) intensity is estimated from measurement at fixed weather stations, and therefore the UHI intensity in the built areas of the city may have been underestimated. This significant difference is of interest for studies on outdoor air temperature, thermal comfort, urban environment and pollutant dispersion. The differences were simulated by an improved one-dimensional temperature model (ZERO-CAT) using different urban morphology parameters. The model can correct the underestimation of street air temperature. Further sensitivity studies show that the building arrangement in the daytime and nighttime plays different roles for air temperature in the street. City designers can choose different parameters based on their purpose.


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