Characterizing Temporal Dynamics of Urban Heat Island in a Rapidly Expanding City: A 39 Years Study in Zhengzhou, China

Abstract

Extreme heat wave weather phenomena have erupted worldwide in recent years. The urban heat island (UHI) effect has exacerbated urban heat waves with serious consequences for urban energy and residents’ health. Therefore, a better understanding of the dynamics of the UHI effect and the influencing factors is needed in the context of carbon neutrality and global warming. This study used long-term observation and statistical data to investigate the urban heat island intensity (UHII) over the past 39 years (1981–2019) and to analyze the temporal changes of the UHI effect and the relationship between the UHI effect and indicators of rapid urbanization in Zhengzhou, China. The results showed that Zhengzhou is warming 2.2-times faster than the global land warming trend of about +0.9 °C from 1981 to 2019. There is a clear phase characteristic of the heat island effect in Zhengzhou, and it offers a rapid upward trend after 2000 and a positive correlation with the urbanization process; it was found that the social and economic conditions of urban expansion in Zhengzhou have a significant relationship with UHII. We also found that the denser the urban built-up area, the more obvious the heat island effect. Compared with other countries, the influence of national policies on urban development is an indirect factor influencing the change of UHI specifically for Chinese cities. This research could provide a reference for understanding the temporal dynamics of UHI in an expanding large city for sustainable urban planning and mitigating urban warming and environmental problems.

Quantitative analysis and optimization of urban park cold island in Wuhan’s main urban area from the perspective of residents’ demand: based on Landsat-8 remote sensing images

“…Meanwhile, the buildings in this area should have a point layout to reserve more green space for urban parks [27]. Furthermore, the road green belt perpendicular to the Yangtze River shoreline should be planned in a manner that could import the cold island effect of the Yangtze River with the flow of wind [28]. The aim is to alleviate the heat island problem in this area and provide residents with sufficient access to parks.…”

An Analysis of the Spatial and Temporal Evolution of the Urban Heat Island in the City of Zhengzhou Using MODIS Data

“…To obtain the value of the UHI intensity (UHI I), the average surface temperature in urban areas (T urban ) is subtracted from the average surface temperature in suburban areas (T rural ), as shown in the following equation [32,35]:…”

“…The heat island area initially increased by 138.72 km 2 between 2006 and 2014. In order to examine the intensity of the UHI in Zhengzhou, China, over a 39-year period (1981-2019), H Li et al conducted a study that used long-term observation and statistical data on annual, seasonal, daytime, and nighttime bases [32]. The associations between UHI and signs of rapid urbanization, as well as the temporal variations in the UHI effect, were also examined in this study.…”