Influence of Urbanization Factors on Surface Urban Heat Island Intensity: A Comparison of Countries at Different Developmental Phases

Yaoping Cui,Xinliang Xu,Yaochen Qin,Jinwei Dong

doi:10.3390/su8080706

Abstract

Urbanization is a global problem with demographic trends. The urban heat island plays a dominant role in local climate systems. Despite existing efforts to understand the impacts of multiple urbanization factors on the urban heat island globally, very little is known about the attribution of urban heat island magnitude to urbanization in different locations or developmental phases. In this study, based on global land surface temperature data, urban spatial domain data, gross domestic product (GDP), and population data, we analyzed the influence of multiple urbanization factors on global surface urban heat island intensity (SUHII). We also tentatively compared the abovementioned factors between different regions across the globe, especially between China and the USA, the largest countries that are experiencing or have experienced rapid urbanization in recent decades. The results showed that global SUHII had remarkable spatial heterogeneity due to the geographical and socioeconomic variation between cities. There was a significant correlation between SUHII and population as well as GDP in global cities. Moreover, this study suggested that the impacts of population on SUHII might be stronger in the early stages of urbanization, and the GDP factor would become a critical factor at a certain development level. The urban area also had non-ignorable impacts on SUHII, while the correlation between SUHII and urban shape was relatively weak. All these may imply that the best approach to slow down SUHII is to find other solutions, e.g., optimize the spatial configuration of urban internal landscapes, when the urbanization reaches a high level.

Highlights

Urbanization has an important impact on the environment
The results of the study demonstrated that land surface temperature (LST) within urban vegetation was affected by the temperature of the surrounding built-up areas, and suburban areas were cooler than the core of the urbanized region [7]
In almost every aspect, accelerating urbanization will lead to a profound impact on local and regional climate, and the urban heat island effect is one of the most well-known phenomena caused by urbanization [8,9]

Summary

Introduction

Urbanization has an important impact on the environment. cities cover a tiny fraction of the world’s surface, urban areas are the nexus of human activity, with more than 50% of the global population and 7%–90% of economic activity [1]. As the core area of human activity, cities affect regional land use and land cover change (LUCC) and affect global climate change [5]. Cities and their surrounding regions tend to experience intensive LUCC due to faster urban sprawl, more population, and intense human activities. The results of the study demonstrated that land surface temperature (LST) within urban vegetation was affected by the temperature of the surrounding built-up areas, and suburban areas were cooler than the core of the urbanized region [7]. In almost every aspect, accelerating urbanization will lead to a profound impact on local and regional climate, and the urban heat island (or surface UHI) effect is one of the most well-known phenomena caused by urbanization [8,9]

Objectives

Findings

Discussion

Conclusion