Influence of Urban Scale and Urban Expansion on the Urban Heat Island Effect in Metropolitan Areas: Case Study of Beijing–Tianjin–Hebei Urban Agglomeration

Mingxing Chen,Maogui Hu,Yaliu Zhou,Yuan Zhou

doi:10.3390/rs12213491

Abstract

Global large-scale urbanization has a deep impact on climate change and has brought great challenges to sustainable development, especially in urban agglomerations. At present, there is still a lack of research on the quantitative assessment of the relationship between urban scale and urban expansion and the degree of the urban heat island (UHI) effect, as well as a discussion on mitigation and adaptation of the UHI effect from the perspective of planning. This paper analyzes the regional urbanization process, average surface temperature variation characteristics, surface urban heat island (SUHI), which reflects the intensity of UHI, and the relationship between urban expansion, urban scale, and the UHI in the Beijing–Tianjin–Hebei (BTH) urban agglomeration using multi-source analysis of data from 2000, 2005, 2010, and 2015. The results show that the UHI effect in the study area was significant. The average surface temperature of central areas was the highest, and decreased from central areas to suburbs in the order of central areas > expanding areas > rural residential areas. From the perspective of spatial distribution, in Beijing, the southern part of the study area, the junction of Tianjin, Langfang, and Cangzhou are areas with intense SUHI. The scale and pace of expansion of urban land in Beijing were more than in other cities, the influencing range of SUHI in Beijing increased obviously, and the SUHI of central areas was most intense. The results indicate that due to the larger urban scale of the BTH urban agglomeration, it will face a greater UHI effect. The UHI effect was also more significant in areas of dense distribution in cities within the urban agglomeration. Based on results and existing research, planning suggestions are proposed for central areas with regard to expanding urban areas and suburbs to alleviate the urban heat island effect and improve the resilience of cities to climate change.

Highlights

With the rapid development of urbanization, more serious ecological and environmental problems will occur
With combined land-use and surface temperature data, we analyzed the spatiotemporal characteristics of urban land expansion and the heat island effect in the BTH urban agglomeration
surface urban heat island (SUHI) in Beijing was the largest, and the temperature differences decreased with the extension outward from the center

Summary

Introduction

With the rapid development of urbanization, more serious ecological and environmental problems will occur. By 2030, more than 1.2 million km of land is projected to convert to new urban areas, which is nearly twice of urban areas in 2000, and the half of expansion will be concentrated in Asia [2]. Cities account for less than 2% of the Earth’s surface, intense activities result in 78% of the world’s energy consumed by cities and more than 60% of greenhouse gas emissions produced from them [6]. This has intensified the trend of global warming, and the degree and frequency of extreme high-temperature weather [7]. It is of great scientific significance to study the impact of urban expansion on the UHI effect to improve the adaptability and resilience of cities to climate change

Methods

Results

Conclusion