Article
Environmental Sciences
Mikhail Varentsov, Daniel Fenner, Fred Meier, Timofey Samsonov, Matthias Demuzere
Summary: This study investigates the contributions of local-scale and mesoscale driving factors to the nocturnal canopy layer UHI in the Moscow megacity, based on air temperature observations from reference and crowdsourced citizen weather stations. The spatial patterns of the UHI are shown to be shaped by both local-scale and mesoscale factors, highlighting the importance of considering both scales in urban climate studies for megacities. Additionally, there is a need to extend the LCZ concept to incorporate mesoscale settings of the urban environment.
FRONTIERS IN ENVIRONMENTAL SCIENCE
(2021)
Article
Construction & Building Technology
Guang Chen, Yiqi Chen, Xiao Tan, Lihua Zhao, Yunnan Cai, Li Li
Summary: The urban heat island (UHI) effect has significant implications on urban development, human health, and climate change. Local climate zones (LCZs) provide a systematic classification method for studying the UHI effect. This study analyzed the UHI effect in six LCZs in Guangzhou and found variations in UHI characteristics under different weather conditions. The study provides important insights for understanding and mitigating the UHI in LCZs.
BUILDING AND ENVIRONMENT
(2023)
Article
Geography
Tianxing He, Rui Zhou, Qun Ma, Chunlin Li, Dan Liu, Xuening Fang, Yina Hu, Jun Gao
Summary: Urban heat island (UHI) is a critical issue in the context of global environmental change and regional sustainability. This study used satellite images to quantify the effects of urban development intensity (UDI) on surface UHI intensity (SUHII) in 20 cities across 5 building climate zones of China and analyzed their potential influence mechanisms. The results showed significant spatial heterogeneity of SUHII and a stronger effect of UDI on SUHII in northern cities. Building density was identified as the most critical predictor of SUHII.
Article
Construction & Building Technology
Guang Chen, Hao He, Yiqi Chen, Lihua Zhao, Yunnan Cai, Yuan Ma
Summary: This study proposes a diagnostic equation for measuring urban heat island intensity based on meteorological data and urban characteristics. It found that the original equation underestimates the intensity in certain urban areas, so a revised equation is introduced, which shows higher accuracy.
BUILDING AND ENVIRONMENT
(2023)
Article
Environmental Sciences
Weishou Tian, Yuanjian Yang, Linlin Wang, Lian Zong, Yanhao Zhang, Duanyang Liu
Summary: This study quantifies and explains the spatial and temporal variations of canopy urban heat island intensity (CUHII) in the megacity of Nanjing, China. It also examines the association between CUHII and heat waves (HWs) and identifies the potential drivers. The results show a significant diurnal variation in CUHII, with a valley during the day and a peak at night. CUHII is stronger during HW periods, especially during the day, which contributes to higher HW intensity. The interannual variability of CUHII is mainly influenced by anthropogenic heat emissions and air pollution, while the spatial patterns are shaped by local climate zones and urban ventilation.
Article
Construction & Building Technology
Yingsheng Zheng, Chao Ren, Yuan Shi, Steve H. L. Yim, Derrick Y. F. Lai, Yong Xu, Can Fang, Wenjie Li
Summary: In this study, night-time mobile measurements were employed to monitor the variation of urban heat island in Hong Kong. The results revealed that sky view factor, street length, and pervious surface fraction were the most explanatory variables of local UHI intensity. The findings suggest that an optimal design of urban morphology is crucial for mitigating heat island effect and climate adaptation.
BUILDING AND ENVIRONMENT
(2023)
Article
Environmental Sciences
Yongjuan Guan, Jinling Quan, Ting Ma, Shisong Cao, Chengdong Xu, Jiali Guo
Summary: This study provides insights into the diurnal characteristics and driving mechanisms of surface urban heat islands (SUHIs) across different local climate zones (LCZs) in Beijing. The researchers identified six prevalent diurnal SUHII patterns and explored the impacts of various factors on the spatial differentiations of SUHIs. The findings enhance our understanding of the continuous dynamics of SUHIs in response to environmental conditions.
Article
Construction & Building Technology
Yang Xiang, Qingya Cen, Chucai Peng, Chunbo Huang, Changguang Wu, Mingjun Teng, Zhixiang Zhou
Summary: This study used source-sink theory and local climate zone (LCZ) analysis to identify key areas for urban heat island (UHI) mitigation. The results showed that open high-rise and open mid-rise buildings are the main heat source landscapes, while low plants and water are the main heat sink landscapes. Based on these findings, it is recommended to split the heat source landscapes, increase the area of smaller heat sink landscapes, and renew the LCZs with lower UHI intensity.
BUILDING AND ENVIRONMENT
(2023)
Article
Meteorology & Atmospheric Sciences
Tian Liang, Jianjun He, Liang Chen, Zhangyu Yao, Lei Zhang, Huizheng Che, Sunling Gong
Summary: The study simulated the urban heat island effect in Beijing using the WRF model coupled with the SLUCM model, and found that simulations using MODIS land use data were closer to observations than those using LCZ data. Sensitivity analysis of urban canopy parameters provided priority parameters for model improvement.
ATMOSPHERIC RESEARCH
(2021)
Article
Construction & Building Technology
Gizem Akkose, Cagla Meral Akgul, Ipek Gursel Dino
Summary: This study investigates the impact of CC&UHI on educational building performance and demonstrates the effectiveness of passive retrofit scenarios targeting CC&UHI mitigation and adaptation.
JOURNAL OF BUILDING ENGINEERING
(2021)
Article
Remote Sensing
Wenzhi Zhang, Hongyuan Huo, Xiaowei Geng, Ping Zhou, Li Guo, Zhao-Liang Li
Summary: This study aims to simulate and quantitatively analyze the urban canopy heat island effect at the block scale in Beijing. The results show that the canopy heat island effect weakens outward from the city center, mainly due to the dense distribution of compact local climate zones in the center of Beijing. The intensity of the canopy heat island effect is significantly stronger in built-up areas compared to natural-covered areas.
INTERNATIONAL JOURNAL OF REMOTE SENSING
(2023)
Article
Construction & Building Technology
Ran Wang, James Voogt, Chao Ren, Edward Ng
Summary: The study investigates the spatial-temporal characteristics of surface urban heat island intensity (SUHII) and extent (SUHIE) across diverse climate zones in large Chinese cities. The results show that SUHII varies across seasons, times, and background climate, with higher values during summer days and lower values during winter days. SUHIE exhibits a similar temporal pattern and shows an increasing trend. The study provides evidence-based planning recommendations to mitigate urban heat and create a comfortable built environment.
BUILDING AND ENVIRONMENT
(2022)
Article
Environmental Sciences
Nada Badaro-Saliba, Jocelyne Adjizian-Gerard, Rita Zaarour, Georges Najjar
Summary: Thermal remote sensing is widely used for studying Urban Heat Island, with the Local Climate Zone scheme established as the standard for assessing UHI intensity. Research shows that urban structure has a significant impact on spatial variability of surface temperature after removing topography effects, with different urban variables affecting temperature to varying degrees.
Article
Construction & Building Technology
Pan Dong, Sida Jiang, Wenfeng Zhan, Chunli Wang, Shiqi Miao, Huilin Du, Jiufeng Li, Shasha Wang, Lu Jiang
Summary: Investigated the diurnally continuous dynamics of surface urban heat island intensities (SUHIIs) of various local climate zones (LCZs) in Nanjing, China, and discovered some patterns.
BUILDING AND ENVIRONMENT
(2022)
Article
Construction & Building Technology
Dionysia Kolokotsa, Katerina Lilli, Kostas Gobakis, Angeliki Mavrigiannaki, Shamila Haddad, Samira Garshasbi, Hamed Reza Heshmat Mohajer, Riccardo Paolini, Konstantina Vasilakopoulou, Carlos Bartesaghi, Deo Prasad, Mattheos Santamouris
Summary: Urban and building typologies have a significant impact on the urban heat island intensity. This study analyzed the effect of various factors, such as building height, street width, aspect ratio, built area ratio, orientation, and dimensions of open spaces, on the distribution of ambient and surface temperature in open spaces. The study found that a higher aspect ratio of the precinct leads to lower cooling potential, and a higher built area ratio decreases the cooling contribution of mitigation measures.
Article
Construction & Building Technology
Fan Liu, Hua Qian, Zhiwen Luo, Xiaohong Zheng
Summary: Exhaled jets from an infected person can be locked at a certain height in rooms with thermal stratification, increasing the risk of disease transmission. The study analyzes the dynamic characteristics of human speech droplets in different thermal environments and finds that thermal stratification has varying effects on droplet residues based on size. These findings have implications for developing effective engineering methods to limit the spread of infectious diseases.
Article
Environmental Sciences
Fan Liu, Zhiwen Luo, Yuguo Li, Xiaohong Zheng, Chongyang Zhang, Hua Qian
Summary: The study found that the universal 2-meter physical distancing rule based on droplet physics is not always applicable in realistic indoor settings and could potentially increase disease transmission risks. In thermally stratified environments, the infection risk may exhibit multiple peaks beyond 2 meters. Therefore, it is suggested to combine various strategies such as wearing masks, reducing exposure time, and controlling indoor thermal stratification in disease prevention.
ENVIRONMENT INTERNATIONAL
(2021)
Article
Environmental Sciences
Vasilis Kazakos, Jonathon Taylor, Zhiwen Luo
Summary: During the COVID-19 lockdown in the Greater London Area, population exposure to NO2 significantly decreased by 52.3% +/- 6.1%, while exposure to PM2.5 showed a smaller reduction of 15.7% +/- 4.1%. Changes in population activity had the strongest influence on exposure levels during morning rush hours, leading to a significant decrease in exposure at 08:00 am. Additionally, the impacts of air pollution exposure varied across different socioeconomic status groups, with a disproportionate positive effect on economically deprived communities in the city.
ENVIRONMENTAL RESEARCH
(2021)
Article
Environmental Sciences
Xia Yang, Hongyu Yang, Cuiyun Ou, Zhiwen Luo, Jian Hang
Summary: This study investigates the evaporation and transport of virus-laden droplets in an open outdoor environment through CFD simulations. Results show that background wind speed and social distance play important roles in droplet dispersion and exposure. A high outdoor wind speed does not necessarily lead to a smaller exposure risk, and proper distancing and positioning are suggested for people outdoors.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Meteorology & Atmospheric Sciences
Said Munir, Zhiwen Luo, Tim Dixon
Summary: This study compared three main approaches to evaluate the impact of COVID-19 lockdown on urban air quality, finding that the parallel and machine learning approaches resulted in higher reductions, while the sequential approach performed poorly and is not recommended. The study highlights the importance of considering different factors like monitoring site environment and data type in interpreting results related to pollutant concentrations.
ATMOSPHERIC RESEARCH
(2021)
Article
Construction & Building Technology
Xiaoxiong Xie, Zhiwen Luo, Sue Grimmond, Ting Sun, William Morrison
Summary: This study proposes a "spin-up" approach to update the external surface temperature of surrounding buildings, aiming to improve the accuracy of evaluating the energy and thermal performance of buildings. The experimental results show that neglecting the influence of the surroundings on buildings in dense urban areas can cause significant biases in critical indicators, especially in lower latitudes.
BUILDING AND ENVIRONMENT
(2022)
Article
Construction & Building Technology
Qiqi Luo, Cuiyun Ou, Jian Hang, Zhiwen Luo, Hongyu Yang, Xia Yang, Xuelin Zhang, Yuguo Li, Xiaodan Fan
Summary: This study investigates the influencing mechanism of crowded and poorly ventilated buses on infection risks of respiratory diseases. Experimental and CFD simulation results show that the initial droplet diameters, air change rates, and relative humidity have integrated effects on pathogen-laden droplet dispersion and infection risks. Large droplets are mainly affected by gravity, while the dispersion of 5 μm droplets is influenced by ventilation.
BUILDING AND ENVIRONMENT
(2022)
Article
Environmental Sciences
Qingman Li, Jie Liang, Qun Wang, Yuntong Chen, Hongyu Yang, Hong Ling, Zhiwen Luo, Jian Hang
Summary: Rapid urbanisation and rising vehicular emissions contribute to urban air pollution and residents' exposure to outdoor pollutants which can infiltrate indoors. This study used CFD simulations to investigate the effects of building configurations and tree planting on airflows, pollutant dispersion, and personal exposure in urban micro-environments. The results provide helpful scientific references for public health and sustainable urban planning.
INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH
(2022)
Article
Construction & Building Technology
Xiaowei Lyu, Zhiwen Luo, Li Shao, Hazim Awbi, Samuele Lo Piano
Summary: CO2-based infection risk monitoring is essential during the COVID-19 pandemic. However, existing CO2 monitoring thresholds are not suitable for spaces with changing occupancy. This study proposes a new calculation framework for deriving safe excess CO2 thresholds, Ct, in various spaces and analyzes the uncertainties involved. Ct varies significantly based on specific space factors, and accurate emissions data is crucial in determining Ct.
BUILDING AND ENVIRONMENT
(2023)
Article
Construction & Building Technology
Xiaoxiong Xie, Zhiwen Luo, Sue Grimmond, Lewis Blunn
Summary: Wind pressure coefficients (Cp) play a critical role in building energy simulations. Different categories exist based on the height of free stream wind speed: Cpr (reference height) and Cpl (local opening height). However, the influences of vertical wind profile and surrounding buildings on Cp data are often overlooked in building energy simulations.
BUILDING AND ENVIRONMENT
(2023)
Article
Construction & Building Technology
Yiqing Liu, Zhiwen Luo, Sue Grimmond
Summary: This study investigates the influences of building envelope design parameters on anthropogenic heat fluxes from buildings (QF,B) in Beijing. The results show that the most important building parameters affecting QF,B are U-value and thermal mass. Decreasing U-value can significantly reduce QF,B in winter, while increasing thermal mass can shift the diurnal pattern of QF,B in autumn and spring. Therefore, appropriate building envelope designs and natural ventilation should be considered to achieve both energy-saving and improved outdoor thermal environment.
BUILDING AND ENVIRONMENT
(2023)
Article
Construction & Building Technology
Xiaoxiong Xie, Zhiwen Luo, Sue Grimmond, Ting Sun
Summary: This study combines SUEWS and EnergyPlus to predict natural ventilation potential (NVP) and cooling energy saving in urban neighborhoods in five Chinese cities. The findings show that the differences in NVP and cooling energy saving between urban and rural areas are climate- and season-dependent, with single-sided ventilation being as effective as cross ventilation in dense urban areas. Considering local or neighborhood-scale climate is important when evaluating NVP.
BUILDING AND ENVIRONMENT
(2023)
Article
Environmental Sciences
Yiqing Liu, Zhiwen Luo, Sue Grimmond
Summary: Buildings are a significant source of anthropogenic heat emissions, which have implications for energy use and human health in cities. This study re-evaluates the definition of anthropogenic heat flux from buildings and proposes a new approach to quantify the differences between building energy consumption and heat emission. The research findings demonstrate the importance of storage heat fluxes in buildings and their relationship with human activities.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2022)
