Toward cooler cities by larger homogeneous functional clusters
8 affiliations
- 1Department of Geography, Ghent University, Ghent 9000, Belgium
- 2Medical Research Council Centre for Global Infectious Disease Analysis, Department of Infectious Disease, School of Public Health, Imperial College London, London W12 0BZ, United Kingdom
- 3Guangdong Key Laboratory for Urbanization and Geo-Simulation, School of Geography and Planning, Sun Yat-sen University, Guangzhou 510275, China
- 4SILC Business School, Shanghai University, Shanghai 201800, China
- 5Department of Land Economy, University of Cambridge, Cambridge CB2 1RX, United Kingdom
- 6State Key Laboratory of Remote Sensing and Digital Earth, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100094, China
- 7University of Chinese Academy of Sciences, Beijing 101408, China
- 8Division of Arts and Sciences, New York University Shanghai, Shanghai 200124, China
Abstract
Urban heat island (UHI) intensifies heat-related risks and environmental degradation in cities worldwide, yet existing mitigation strategies have largely overlooked how the spatial scale of homogeneous functional building clusters influences local climate. This scale may matter because buildings with similar functions often share similar morphology, activity schedules, and anthropogenic heat-release patterns, allowing their spatial contiguity to shape ventilation and heat accumulation. Here, we introduce the Urban Homogeneous Scale (UHS)—an indicator that measures the spatial scale of contiguous, functionally similar building clusters—and analyze 233,844 observations across 101 global cities to assess its potential for mitigating surface UHI. We find that larger UHS is associated with lower surface UHI: every 100-meter increase in UHS corresponds to 4.5% decrease in daytime UHI. This daytime cooling effect is particularly more pronounced in inland, humid, and high-income regions. In low-income regions, larger building area and higher building volume more strongly weaken UHS cooling capacity than in wealthier regions, revealing a socioeconomic inequality in UHS’s mitigation benefits. Our findings identify the spatial scale of building clusters as a essential dimension of urban form associated with urban heat burden, and suggest that considering UHS alongside targeted controls on built environmental characteristics may inform future heat-mitigation planning.
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BibTeX
@article{zhang2026toward,
title = {{Toward cooler cities by larger homogeneous functional clusters}},
author = {Xucai Zhang and Xiaobing Wei and Xiaoping Liu and Honghong Wei and Yue Zheng and Hongkai Gu and Yangzi Che and Yeran Sun and Ming Luo and Weilin Liao and Haosheng Huang and Kangning Huang},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
year = {2026},
month = oct,
doi = {10.1073/pnas.2617717123},
url = {https://doi.org/10.1073/pnas.2617717123},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - JOUR
TI - Toward cooler cities by larger homogeneous functional clusters
AU - Xucai Zhang
AU - Xiaobing Wei
AU - Xiaoping Liu
AU - Honghong Wei
AU - Yue Zheng
AU - Hongkai Gu
AU - Yangzi Che
AU - Yeran Sun
AU - Ming Luo
AU - Weilin Liao
AU - Haosheng Huang
AU - Kangning Huang
PY - 2026
DA - 2026/10/19
JO - Proceedings of the National Academy of Sciences of the United States of America
DO - 10.1073/pnas.2617717123
UR - https://doi.org/10.1073/pnas.2617717123
AB - Urban heat island (UHI) intensifies heat-related risks and environmental degradation in cities worldwide, yet existing mitigation strategies have largely overlooked how the spatial scale of homogeneous functional building clusters influences local climate. This scale may matter because buildings with similar functions often share similar morphology, activity schedules, and anthropogenic heat-release patterns, allowing their spatial contiguity to shape ventilation and heat accumulation. Here, we introduce the Urban Homogeneous Scale (UHS)—an indicator that measures the spatial scale of contiguous, functionally similar building clusters—and analyze 233,844 observations across 101 global cities to assess its potential for mitigating surface UHI. We find that larger UHS is associated with lower surface UHI: every 100-meter increase in UHS corresponds to 4.5% decrease in daytime UHI. This daytime cooling effect is particularly more pronounced in inland, humid, and high-income regions. In low-income regions, larger building area and higher building volume more strongly weaken UHS cooling capacity than in wealthier regions, revealing a socioeconomic inequality in UHS’s mitigation benefits. Our findings identify the spatial scale of building clusters as a essential dimension of urban form associated with urban heat burden, and suggest that considering UHS alongside targeted controls on built environmental characteristics may inform future heat-mitigation planning.
SN - 0027-8424
SN - 1091-6490
ER -