The relationship between urban form and heat island intensity along the urban development gradients

Ze Liang; Shuyao Wu; Yueyao Wang; Feili Wei; Jiao Huang; Jiashu Shen; Shuangcheng Li

doi:10.1016/j.scitotenv.2019.135011

The relationship between urban form and heat island intensity along the urban development gradients

Sci Total Environ. 2020 Mar 15:708:135011. doi: 10.1016/j.scitotenv.2019.135011. Epub 2019 Nov 4.

Authors

Ze Liang¹, Shuyao Wu¹, Yueyao Wang¹, Feili Wei¹, Jiao Huang¹, Jiashu Shen¹, Shuangcheng Li²

Affiliations

¹ College of Urban and Environmental Sciences, Peking University, Beijing 100871, China; Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing 100871, China.
² College of Urban and Environmental Sciences, Peking University, Beijing 100871, China; Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing 100871, China. Electronic address: scli@urban.pku.edu.cn.

PMID: 31806300
DOI: 10.1016/j.scitotenv.2019.135011

Abstract

There is an increasing demand for urban form optimization to mitigate urban heat island (UHI) effect under the background of global climate change and urbanization. However, there is still a lack of understanding about how the relationship between urban form and UHI intensity changes under diverse urbanization contexts. This study aims to show the change patterns of the relationship between urban form and UHI intensity along the urban development gradient based upon the investigation of a total of 150 urban areas in the Jing-Jin-Ji region in China in 2000, 2005, 2010 and 2015. We defined a comprehensive urban development index taking into account the size of urban area, population density and night light intensity to classify the different levels of urban development. A multi-model comparison was carried out to validate the results. We found that the increase in urban continuity, sprawling, scale and density all enhanced UHI effect at the regional scale. However, the relationship between urban form indicators and UHI intensity demonstrated two opposite patterns along the urban development gradient: population density, geometric complexity and continuity, and general vegetation index of a city were found to be increasingly influential, while night light intensity, geometric elongation and forest coverage presented declining influence. Finally, the study obtained an ascending contribution rate curve for urban geometry indicators, a convex curve for urban size indicators and a declining curve for urban vegetation. These changes along the urban development gradient may be closely related to the changes of the microclimate in cities due to land use, social and economic activities in different urban development stages. The findings can contribute to more appropriate and effective urban planning in countries and regions undergoing rapid urbanization as a valuable reference.

Keywords: Change pattern; Contribution rate curve; Gradient; Urban development; Urban form; Urban heat island.