Multi-scale spatiotemporal patterns of urban climate effects and their driving factors across China

Abstract

Urbanization significantly impacts the local climate, leading to the urban climate effect. This study analyzed urban climate phenomena like urban heat islands (UHI), urban wet islands (UWI), urban dry islands (UDI), and urban wind-blocking (UW) in China. The research across 17 provinces showed consistent patterns of UHI, UWI, and UDI, with more pronounced effects in northern regions. The effects were stronger in central districts compared to suburban fringes, especially evident in spring and winter. Urban layout and location played significant roles in these effects, along with vegetation and air temperature influencing UWI and UDI. While urban wind speeds had minor differences between cities, they varied significantly within cities due to building density. Urban-suburban air temperature differences followed a distinct ‘U' curve, peaking at night, while urban-suburban relative humidity ratios showed an inverted ‘U' pattern. These findings underscore significant microclimatic differences between urban and suburban regions in China, shaped by factors like buildings, vegetation, and city climate. This study's insights are crucial for urban and regional planning to foster sustainable and healthy urban environments.