中国西北部での極端な降水の増加を確認(Extreme Precipitation Is on the Rise in Arid Northwest China, Study Finds)

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2025-04-11 中国科学院(CAS)

中国西北部での極端な降水の増加を確認(Extreme Precipitation Is on the Rise in Arid Northwest China, Study Finds)
Schematic diagram of main processes affecting extreme precipitation in arid Northwest China. (Image by XIEG)

中国科学院・新疆生態地理研究所のCHEN Yaning氏らの研究によると、地球温暖化の影響により、中国西北部の乾燥地域における極端降水現象(EPEs)の頻度、強度、持続時間が著しく増加しています。1961年から2022年までの気候データ(CN05.1)と複数の大気循環因子を用いて、6つの極端降水指標の傾向を分析した結果、無降水日数は年平均0.65日減少し、一方で大雨日数、年間降水量、最大日降水量はそれぞれ増加傾向にあります。また、EPEsの強化には、大西洋・インド洋・太平洋における海面温度異常が関与し、水蒸気の輸送を促進する大気循環の変化を引き起こしていることが判明しました。本研究は、地域の水資源管理や洪水警報、エコロジー政策の策定に重要な知見を提供します。

<関連情報>

1961-2022年の中国北西部乾燥地域における異常降水量の時間的・空間的変化とそれに関連する大規模気候メカニズム Temporal and spatial changes of extreme precipitation and its related large-scale climate mechanisms in the arid region of Northwest China during 1961–2022

Qixiang Liang, Yaning Chen, Weili Duan, Chuan Wang, Yupeng Li, JianYu Zhu, Ganchang He, Wei Wei, Mengqi Yuan
Journal of Hydrology  Available online: 24 March 2025
DOI:https://doi.org/10.1016/j.jhydrol.2025.133182

Highlights

  • Between 1961 and 2022, extreme precipitation events in the arid regions of Northwest China became more intense and frequent.
  • Sea surface temperature anomalies are the main drivers of EPEs in ANC.
  • The interaction of multiple climate factors has greater influence on extreme precipitation than that of a single factor.

Abstract

Extreme precipitation events (EPEs) have an important impact on the hydrological cycle and are the main factors that cause causing flood disasters. Based on the CN05.1 dataset and large-scale circulation factors, six EPE indices are selected to detect changes in extreme precipitation in the arid Northwest China (ANC) region from 1961 to 2022. The correlation between 13 climate factors and EPEs is investigated using the geographic detector model (GDM). The results indicate the following: (1) During the study period, the number of consecutive days without precipitation (CDD) in the extreme precipitation index decreased by 0.65 days per year, and the number of heavy precipitation days increased by 0.0099 days per year. Further, the proportion of annual heavy precipitation days, the mount of annual total precipitation, and the amount of annual maximum single-day precipitation increased by 0.067 %/a, 0.49 mm/a and 0.42 mm/a, respectively. The spatio-temporal intensity, duration and frequency of EPEs also showed an upward trend. (2) EPEs increased significantly in different sub-regions, rising the fastest in northern Xinjiang, followed by the Hexi Corridor, southern Xinjiang, and eastern Xinjiang. (3) Sea-surface temperature anomalies are the main factor leading to the increases in EPEs in ANC. Temperature anomalies in the Atlantic Ocean, Indian Ocean, and Pacific Oceans caused a series of circulation anomalies, increasing water vapor transport to and through China’s Northwest. This study contributes to a more comprehensive understanding of EPE changes in regional water resources and also provides a reference for regional water resources management and disaster prevention.

1702地球物理及び地球化学
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