Responses of extreme high temperatures to urbanization in the Beijing–Tianjin–Hebei urban agglomeration in the context of a changing climate

Abstract

Extreme high-temperature event is one of the most urgent climate issues faced by coordinated development of the Beijing-Tianjin-Hebei region (BTH) in the future due to global warming and urbanization. Based on the homogenized daily temperatures from 174 meteorological observation stations, six extreme hot events were detected. The results revealed the spatiotemporal change characteristics of the extreme high temperature in the BTH. The acquired evidence showed the maximum daily minimum temperature (TNx), high-temperature days (SU35), hot night days (TR25), and heatwave spell durations (HWDI) have significantly increased, while the daily temperature range (DTR) has significantly decreased (p < 0.01) during 1961-2018. The SU35, TR25 and HWDI in 2010s were 68%, 2.8 times and 2.1 times higher than that in 1980s, respectively. Moreover, since 1961, the high-temperature season in the BTH has been getting longer at a rate of 7.4d/10a. The study also revealed the contribution of urbanization on high-temperature indices depends on city size and location in the BTH. The magnitudes of the indices change in the downtown area of Beijing, Tianjin and Shijiazhuang ranked top in the 13 cities of the BTH, which are closely related to the urban development. The mean contribution of urbanization on maximum daily maximum temperature (TXx), TNx, SU35 and TR25 was 68%, 45% and 27% in Beijing, Tianjin and Shijiazhuang, respectively. The socio-economic driving factors have an important impact on the change rates of the extreme high-temperature indices, which means that controlling population, city size and reducing energy consumption could effectively alleviate the urban heat island (UHI) effect and slow down the high-temperature events in the BTH. In the future, it is vital to further study and investigate the mechanism of the extreme high-temperature changes through numerical simulations and to research their impact and response in this region.

Urbanization Amplified Compound Hot Extremes Over the Three Major Urban Agglomerations in China

“…It may be associated with the larger proportion of impervious surface area and the enhanced WPSH (Chen et al., 2020). A relatively small increase in the BTH is possibly due to the cooling caused by intense haze pollution and expanding irrigation (Wang, Chen, et al., 2021; Wang, Ren, et al., 2021; Wu et al., 2018). As to the intensity of CHEs, it was the strongest with the most significant increase in the YRD, followed by the PRD and the BTH.…”

“…Trenberth and Fasullo (2012) pointed out that the CHE in 2010 led to widespread wildfires in Russian, inducing devastating losses of human life and economy. It is projected that the frequency of CHEs will increase by two to five times in the 2090s compared to the 2010s in China (Wang, Chen, et al., 2021; Wang, Ren, et al., 2021). By the mid‐21st century, 50% of land area of the BTH, YRD, and PRD will experience CHEs unprecedented in history (Wang et al., 2020).…”

“…The limited nighttime relief of excessive heat produced by UHI may cause sustained heat stress during the day and night (Liao et al., 2021; Ren & Zhou, 2014). Thus, the increased HEs in daytime and nighttime resulted in frequent compound hot extremes (CHEs, defined as both daytime and nighttime extreme hot event occurring on the same day) in these agglomerations (An & Zuo, 2021; Chen & Zhai, 2017; Shi et al., 2021; Wang, Chen, et al., 2021; Wang, Ren, et al., 2021; Wu et al., 2021). Compared with individual events, CHEs amplify adverse effects from both daytime and nighttime extremes, leading to more profound impacts on human society and ecosystems (Chen & Zhai, 2017; Grumm, 2011; Zscheischler et al., 2020).…”

Editorial: Atmospheric processes and applications in urban, coastal and mountainous terrain

“…The authors highlight that past land cover changes (from 1878 to 2012) had a significant effect on urban temperatures, while weaker variations are estimated for the future since the growth of the urban area is expected to be less significant. On the other hand, the effects of ongoing climate change on urban conditions are evaluated by Wang et al (2021), who analyse data from 174 meteorological stations in the Beijing‐Tianjin‐Hebei region (China) to evaluate trends in six ETCCDI indices. The authors highlight increasing trends for most of the indices, also showing the significant contribution of urbanisation.…”

Land Use Dynamic Changes in an Arid Inland River Basin Based on Multi-Scenario Simulation

“…In the process of socioeconomic development, different regions have a variety of land use needs as well as unique land use structure characteristics [71,72]. Wang et al argued that regional planning policies can influence the degree of urbanization [73], whereas Gong et al reported that while the implementation of land use policies is beneficial to ecosystem functioning, it may also exacerbate water scarcity [74]. Therefore, it is necessary to link socio-economic with sustainable development, and to optimize and adjust the regional land structure and rationalize the use of regional land resources.…”