摘要
全球变暖趋势下,黄土高原极端气候事件频发,明确黄土高原极端降水事件的时空特征对区域灾害防范具有重要意义。基于1960—2023年黄土高原111个气象站点的日降水数据,通过去趋势波动分析(DFA)法确定极端降水阈值来识别极端降水事件,采用Mann-Kendall检验等方法分析黄土高原全区及生态分区的极端降水事件特征。结果表明:(1)黄土高原各气象站的极端降水阈值介于27.4~89.1 mm,有54%站点的阈值>50 mm,各生态分区的平均阈值介于35.0~59.6 mm之间,呈西北低、东南高的分布特征。(2)极端降水事件的降水量及强度分别从西北部的10.6 mm·a^(-1)3.0 mm·d^(-1)增至东南部的71.5 mm·a^(-1)、133.0 mm·d^(-1),其发生频率则从北部的0.3 d·a^(-1)增至南部的0.8 d·a^(-1)。极端降水日数更接近于暴雨日数,特别是在黄土丘陵沟壑区B2副区。(3)黄土高塬沟壑区、土石山区及河谷平原区是极端降水事件的高发区,应作为灾害防治重点区域。(4)近64 a的极端降水事件具有明显的年际波动特征,全区的极端降水事件增多,集中在7、8月。(5)近10 a来,黄土高塬沟壑区、黄土丘陵沟壑区的极端降水事件的降水量及频率有所增多;沙地和农灌区的极端降水事件下降趋势减缓,而土石山区及河谷平原区的极端降水事件在2020年发生突变且增多。研究结果为黄土高原各生态分区极端降水事件的防灾减灾提供了参考依据。
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 cru-cial 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 meteo-rological 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 precip-itation 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 re-garding extreme precipitation events across the different ecological regions of the Loess Plateau.
作者
张昕晗
赵文婷
焦菊英
马晓武
杨波
凌麒
ZHANG Xinhan;ZHAO Wenting;JIAO Juying;MA Xiaowu;YANG Bo;LING Qi(College of Soil and Water Conservation Science and Engineering(Institute of Soil and Water Conservation),Northwest A&F University,Xianyang 712100,Shaanxi,China;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)
出处
《干旱区地理》
北大核心
2025年第7期1153-1166,共14页
Arid Land Geography
基金
国家自然科学基金项目(U2243213,42077078)资助。
关键词
极端降水阈值
极端降水事件
时空变化
生态分区
黄土高原
extreme precipitation threshold
extreme precipitation events
temporal and spatial changes
ecolog-ical regionalization
Loess Plateau
作者简介
张昕晗(2000-),女,硕士研究生,主要从事流域水文方面的研究.E-mail:zxh_0630@163.com;通讯作者:焦菊英(1965-),女,博士,研究员,主要从事流域水文、侵蚀灾害方面的研究.E-mail:jyjiao@ms.iswc.ac.cn。
