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Arid Land Geography ›› 2025, Vol. 48 ›› Issue (7): 1153-1166.doi: 10.12118/j.issn.1000-6060.2024.461

• Climatology and Hydrology • Previous Articles     Next Articles

Spatiotemporal evolution characteristics of extreme precipitation events on the Loess Plateau from 1960 to 2023

ZHANG Xinhan1(), ZHAO Wenting1, JIAO Juying1,2(), MA Xiaowu1, YANG Bo2, LING Qi1   

  1. 1. College of Soil and Water Conservation Science and Engineering (Institute of Soil and Water Conservation), Northwest A & F University, Xianyang 712100, Shaanxi, China
    2. State Key Laboratory of Soil Erosion and Dryland Agriculture in the Loess Plateau, Institute of Water and Soil Conservation, Ministry of Water Resources, Chinese Academy of Sciences, Xianyang 712100, Shaanxi, China
  • Received:2024-08-03 Revised:2024-09-21 Online:2025-07-25 Published:2025-07-04
  • Contact: JIAO Juying E-mail:zxh_0630@163.com;jyjiao@ms.iswc.ac.cn

Abstract:

The Loess Plateau of China has been experiencing an increase in extreme climate events due to global warming. Understanding the spatiotemporal characteristics of extreme precipitation events in this region is crucial for disaster prevention. This study analyzes daily precipitation data from 111 meteorological stations across the Loess Plateau, spanning the years 1960 to 2023. Using detrended fluctuation analysis (DFA), we established thresholds for extreme precipitation events and examined their spatiotemporal characteristics through the Mann-Kendall test and other methods. The findings reveal the following. (1) Extreme precipitation thresholds at meteorological stations vary between 27.4 mm and 89.1 mm, with 54% of the stations exceeding a threshold of 50 mm. The average threshold values across different ecological regions range from 35.0 mm to 59.6 mm, exhibiting a gradient that is lower in the northwest and higher in the southeast. (2) The amount and intensity of extreme precipitation events increase from 10.6 mm·a-1 and 33.0 mm·d-1 in the northwest to 71.5 mm·a-1 and 133.0 mm·d-1 in the southeast, respectively. The frequency of their occurrence increases from 0.3 d·a-1 in the north to 0.8 d·a-1 in the south. The number of extreme precipitation days closely aligns with heavy rain days, particularly in the loess hilly gully B2 sub-region. (3) The loess tableland gully, earth-rocky mountainous, and river valley plain regions are identified as high-risk areas for extreme precipitation events and should be prioritized for disaster prevention and control. (4) Over the past 64 years, extreme precipitation events have shown distinct interannual variability, with an overall increase observed, particularly in July and August. (5) In the last decade, the loess tableland gully and loess hilly gully regions have seen increased precipitation amounts and frequencies of extreme events. By contrast, the declining trend of extreme precipitation events in the sandy land and irrigated agricultural regions has slowed, whereas both the earth-rocky mountainous and river valley plain regions experienced a sudden spike in extreme precipitation events in 2020. This study serves as a reference for disaster prevention and mitigation regarding extreme precipitation events across the different ecological regions of the Loess Plateau.

Key words: extreme precipitation threshold, extreme precipitation events, temporal and spatial changes, ecological regionalization, Loess Plateau