Co-occurrence of urban heat and the COVID-19: Impacts, drivers, methods, and implications for the post-pandemic era

Abstract

Cities, the main place of human settlements, are under various mega challenges such as climate change, population increase, economic growth, urbanization, and pandemic diseases, and such challenges are mostly interlinked. Urban heat, due to heatwaves and heat islands, is the combined effect of climate change and urbanization. The COVID-19 is found to be a critical intervention of urban heat. However, the interrelationship between COVID-19 and urban heat has not been fully understood, constraining urban planning and design actions for improving the resilience to the dual impacts of heat and the pandemic. To close this research gap, this paper conducted a review on the co-occurrence of urban heat and the COVID-19 pandemic for a better understanding of their synergies, conflicts or trade-offs. The research involves a systematic review of urban temperature anomalies, variations in air pollutant concentrations, unbalanced energy development, and thermal health risks during the pandemic lockdown. In addition, this paper further explored data sources and analytical methods adopted to screen and identify the interventions of COVID-19 to urban heat. Overall, this paper is of significance for understanding the impact of COVID-19 on urban heat and provides a reference for coping with urban heat and the pandemic simultaneously. The world is witnessing the co-existence of heat and the pandemic, even in the post-pandemic era. This study can enlighten city managers, planners, the public, and researchers to collaborate for constructing a robust and resilient urban system for dealing with more than one challenges.

Keywords: City manager; Co-occurrence; Pandemic; Urban governance; Urban heat.

Fig. 1

The framework for urban heat concept, changes, considerations and recommendations.

Fig. 2

Distribution of academic research related to urban heat and COVID-19 in countries worldwide.

Fig. 3

Depicting the thematic classifications and percentages in the reviewed COVID-19 and urban heat literatures.

Fig. 4

Assessment indicators for analyzing temperature-related anomalies during the COVID-19 pandemic.

Fig. 5

Distribution of cities as the study context of urban temperature anomalies during the COVID-19. (Cai et al., 2021; Taoufik et al., 2021; Nanda et al., 2021; Nakajima et al., 2021) Parida et al., 2021; Nanda et al., 2021; Potter et al., 2021; Maithani et al., 2020; Wai et al., 2022; Das et al., 2021; Lele et al., 2021; Chakraborty et al., 2021; Sai et al., 2021; Shikwambana et al., 2021; Roshan et al., 2021; El Kenawy et al., 2021; Agni et al., 2021; Roshan et al., 2022; Liu et al., 2022b).

Fig. 6

Trends in urban heat input during the COVID-19 pandemic lockdown.

Fig. 7

The AOD variations in lockdown period in 2020 compared to 2019. (Pal et al., 2022; Ali et al., 2021; Ghasempour et al., 2021; Alqasemi et al., 2021; Miller et al., 2021; Chakraborty et al., 2021; Syed et al., 2021).

Fig. 8

The ozone variations in lockdown period in 2020 compared to 2019. (Pal et al., 2022; Keshtkar et al., 2022; Vuong et al., 2020; Hidalgo Garcia et al., 2022; Syed et al., 2021; Perillo et al., 2022; Fan et al., 2021; Li et al., 2021).

Fig. 9

Comparison of the main research methods on the urban heat before and after the COVID-19 intervention.

Fig. 10

The influence path of urban development and COVID-19 legacy on urban heat in the post-pandemic era.

Fig. 11

Suggestions for urban heat and health action plan in the post-epidemic era.

Appendix 1

Flowchart for screening relevant literature on heat and outbreak research.