1986—2022年山东省极端气温事件及人口暴露度时空变化研究

Spatiotemporal variations of extreme temperature events and population exposure in Shandong Province from 1986 to 2022

摘要

【目的】全球气候变化背景下，由极端天气导致的各类灾害呈多发频发重发态势。明晰极端气温事件及其人口暴露度变化，对于保障人民生命健康和经济社会发展具有重要现实意义。【方法】基于气温日观测资料，运用线性倾向估计、Mann-Kendall检验、滑动t检验和小波分析等方法分析了1986—2022年山东省极端气温事件的时空特征，并结合全国人口普查数据揭示了山东省县域单元极端气温人口暴露度格局变化。【结果】结果表明：(1)在时间序列上，山东省年均高温日数由5.93 d增至12.49 d,上升速率约为2.0 d/10 a(P<0.01),年均冰封日数则以0.1 d/10 a的速率呈略微下降趋势。(2)在空间格局上，山东省年均高温日数整体由东向西逐渐增多，年均冰封日数呈现出北高南低的分布特征。与1986—1995年相比，2013—2022年年均高温日数超过8 d的县域数量增加了227%,而年均冰封日数无明显空间变化。(3)1986—2022年期间，山东省极端高温人口暴露度不断增大，年均人口暴露度由四普时期的525百万人·d增加到七普时期的1257百万人·d,高值区位于鲁西南和鲁中地区；极端低温人口暴露度先增加后减少，高值区主要分布在鲁东半岛地区。【结论】山东省极端高温事件的发生频率和影响范围均呈显著上升趋势，叠加上人口数量变化，极端高温人口暴露度快速增加，而极端低温事件及其人口暴露度先增后减，整体变化幅度较小。

Abstract

[Objective] In the context of global climate change, various disasters caused by extreme weather have become more frequent, recurrent, and severe. Understanding the variations of extreme temperature events and their population exposure holds great practical value for protecting people's lives and health, as well as for promoting economic and social development. [Methods] Using daily temperature observations, the spatiotemporal characteristics of extreme temperature events in Shandong Province from 1986 to 2022 were analyzed by using method including linear trend estimation, Mann-Kendall test, sliding t-test, and wavelet analysis. Combined with the national census data, the variation patterns of population exposure to extreme temperature at the county level in Shandong Province were revealed. [Results] (1) Temporally, the annual average number of high-temperature days in Shandong Province increased from 5.93 d to 12.49 d, with an increasing rate of 2.0 d/10 a(P<0.01), while the annual average number of frozen days showed a slight downward trend at a rate of 0.1 d/10 a.(2) Spatially, the annual average number of high-temperature days in Shandong Province gradually increased from east to west, and the annual average number of frozen days showed a distribution pattern of being higher in the north and lower in the south. Compared with the period from 1986 to 1995, the number of counties with an annual average number of high-temperature days exceeding 8 d increased by 227% during the period from 2013 to 2022, while no significant spatial changes were observed in the annual average number of frozen days.(3) From 1986 to 2022, the population exposure to extreme high temperature in Shandong Province increased continuously, with the annual average population exposure rising from 5.25 million people·d during the Fourth National Population Census to 12.57 million people·d during the Seventh National Population Census. Areas with high values were located in the southwestern and central Shandong. The population exposure to extreme low temperature first increased and then decreased, with high-value areas mainly distributed in the eastern Shandong Peninsula. [Conclusion] Both the frequency and influence range of extreme high-temperature events in Shandong Province have shown significant upward trends. Combined with changes in population size, the exposure to extreme high temperature increases rapidly, while extreme low-temperature events and their population exposure first increase and then decrease, with relatively small overall variations.

关键词

极端气温 / 人口暴露度 / 时空变化 / Mann-Kendall检验 / 县域尺度 / 影响因素

Key words

extreme temperature / population exposure / spatiotemporal variation / Mann-Kendall test / county-level scale / influencing factors

基金资助

国家重点研发计划(2020YFA0608202)

山东省泰山学者青年专家计划(tsqn202103065)

日照市科技成果转化项目(2021CSDX002)