Spatial and Temporal Variation Characteristics of Heatwaves in Recent Decades over China

Abstract

Global warming and rapid socioeconomic development increased the risk of regional and global disasters. Particularly in China, annual heatwaves (HWs) caused many fatalities and substantial property damage, with an increasing trend. Therefore, it is of great scientific value and practical importance to analyze the spatiotemporal changes of HW in China for the sustainable development of regional socioeconomic and disaster risk management. In this study, based on gridded maximum temperature product and specific humidity dataset, an HW evaluation algorithm, considering the impact of humidity on the human body and the characteristics of HW in China, was employed to generate daily HW state at light, moderate, and severe levels for the period 1979–2018. Consequently, the regional differences at three HW levels were revealed, and the changing trend of HW onset, termination, and duration in each subregion was analyzed. The results show that in the three levels, the frequency and duration of HW in China had a significant increasing trend, generally characterized by the advancement of HW onset and the postponement of HW termination. The HW influence at light, moderate and severe levels decreased gradually, with the light level occurring the earliest and terminating the latest. Among the seven subregions, the largest HW frequency happened to be mainly in XJ (Xinjiang), SC (Southern China), and NC (Northern China), while the variations of HW onset and termination had noticeable regional differences at the three levels. The findings presented in this study can provide the essential scientific and technological support for national and regional disaster prevention mitigation and adaptation to extreme climate events.

Increasing heatwave with associated population and GDP exposure in North China

“…However, the increasing North China heatwaves during the past few years have caused significant impacts (Zhang et al, 2020b). In 2018, North China suffered an unusual summer heat event with maximum temperature anomalies exceeding 6°C, inflicting drought on about 65 million acres of farmland and water shortages for more than 4.6 million people (Li et al, 2020a; Liu et al, 2021). Furthermore, the annual heat‐related mortality from heatwaves in each province of North China was beyond 500 in 2019 (Cai et al, 2021).…”

Heat and cold waves in mainland Spain: Origins, characteristics, and trends

“…Gridded datasets offer a continuous representation of climatic variables that, depending on the spatial and temporal resolution as well as the number of observations used to create them, provide reliable and representative climatic information of any spatial domain (Serrano-Notivoli and Tejedor, 2021). The use of gridded temperatures for HWs/CWs analyses has been barely explored except for global or large-region purposes (e.g., Perkins et al, 2012;Lavaysse et al, 2019;Liu et al, 2021) or at finer scales (e.g., Spinioni et al, 2015) and yet, grids can provide a real advantage if they were built on a strong basis due to: 1) the information of all the observations (not only the longest data series) is considered; 2) the value at each grid-box includes the local temperature from the nearby station and also a regional variation from nearby observatories that are used to calculate the temperature estimate; 3) the urban effect is partly removed since data is not exclusive from cities but it is modelled from a collection of adjacent observations. While these premises could reduce the values of the absolute extremes in comparison with the observations, it is, in fact, insignificant because a reliable grid using all the available information offers a similar frequency distribution in the estimates than in the observations.…”

Historic evolution of population exposure to heatwaves in Xinjiang Uygur Autonomous Region, China

“…Also, the number of patients with airway diseases and cerebrovascular diseases due to heatwaves increased significantly. According to the study of Liu et al 21 , with the intensification of global warming, heatwave affected areas will expand, and more severe heatwaves are likely to occur in the future. LHW may occur in regions that have not previously experienced heatwaves, whereas the original LHW may be transformed to MHW or even SHW.…”

“…Heatwaves in the Xinjiang Uygur Autonomous Region have increased significantly over the last few decades 21 , 22 , being expected to occur more continually and intensely in the future 23 . Previous studies in Xinjiang identifies heatwaves by daily maximum.…”