Assessing Urban Risk to Extreme Heat in China

Yanyu Li,Yuhui Guo,Mingyue Qi,Xiaojun Huang,Dianyuan Zheng

doi:10.3390/su12072750

Yanyu Li, Yuhui Guo + Show 3 more

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https://doi.org/10.3390/su12072750

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Abstract

Many cities are experiencing persistent risk in China due to frequent extreme weather events. Some extreme weather events, such as extreme heat hazard, have seriously threatened human health and socio-economic development in cities. There is an urgent need to measure the degree of extreme heat risk and identify cites with the highest levels of extreme heat risk. In this study, we presented a risk assessment framework of extreme heat and considered risk as a combination of hazard, exposure, and vulnerability. Based on these three dimensions, we selected relevant variables from historical meteorological data (1960–2016) and socioeconomic statistics in 2016, establishing an indicator system of extreme heat risk evaluation. Finally, we developed an extreme heat risk index to quantify the levels of extreme heat risk of 296 prefecture-level cities in China and revealed the spatial pattern of extreme heat risk in China in 2016 and their dominant factors. The results show that (1) cities with high levels of extreme heat hazard are mainly located in the south of China, especially in the southeast of China; (2) the spatial distribution of the extreme heat risk index shows obvious agglomeration characteristics; (3) the spatial distribution of the extreme heat risk is still mostly controlled by natural geographical conditions such as climate and topography; (4) among the four types of hazard-dominated, exposure-dominated, vulnerability-dominated, and low risk cities, the number of vulnerability-dominated cities is the largest. The results of this study can provide support for the risk management of extreme heat disasters and the formation of targeted countermeasures in China.

Highlights

In recent years, global climate change has led to a conspicuous increase in the frequency and intensity of extreme weather events, which has posed a serious threat to human well-being [1]
The results show that the spatial distribution of the urban vulnerability index is relatively scattered (Figure 6b)
We establish the Risk Assessment Framework of Extreme Heat based on the risk analysis of IPCC to understand the extreme heat risk as a comprehensive function of hazard, exposure, and vulnerability and develop an extreme heat risk index to measure the risk of extreme heat risk in 296 prefecture-level cities in China

Summary

Introduction

Global climate change has led to a conspicuous increase in the frequency and intensity of extreme weather events, which has posed a serious threat to human well-being [1]. According to the Global Risk Report for four consecutive years from 2017 to 2020, extreme weather events have become the most prominent risk facing the human society [2]. Studies show a total economic loss of 27.49 billion CNY for Nanjing in 2013 due to the heat wave [7] and 167 excess deaths in Shanghai’s Pudong New Area [8]. Relevant research reports indicate that global extreme heat events will occur more frequently and for longer durations, and the risk to human society will be more serious in the future [9]. How to mitigate the risk of extreme heat, adapt to future climate change, and establish a climate-safe society have become major realistic challenges facing humanity today

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