1965—2019年中国夏季分钟降水空间分布与长期趋势分析

An analysis of minute summer precipitation in China during 1965—2019

  • 摘要: 短时强降水可引起洪涝等气象灾害,揭示其气候分布和长期变化特征对于防灾、减灾和气候变化应对等工作非常重要。利用较为完整的中国夏季1965—2004年的自记纸(2225站)以及2005—2019年的自动站(2435站)分钟降水数据,分析了中国大陆分钟降水的空间分布和长期变化特征。结果表明,中国夏季分钟降水频率基本呈现从北到南增加的特征,分钟降水强度在西北地区较小,东部平原地区较大。1 min、连续5 min最大一次降水量在内蒙古、华北最多,连续10 min以上的最大一次降水量和年平均最大降水量在华南沿海地区最多,上述指标的最小值都出现在南疆一带。1965—2004年以及2005—2019年,夏季分钟降水频率都存在增加趋势,是引起中国平均夏季降水量增加的主要原因;分钟降水强度则没有明显趋势性变化。1965—2019年数分钟到一日的最大降水量距平百分率都显著增加,其中连续半小时左右的最大降水量增加最快。总体来看,中国大陆每分钟的降水并未趋向于极端化,极端降水量的增加可主要归因于暴雨过程持续时间的增加。

     

    Abstract: Short-term heavy precipitation can cause floods and other meteorological disasters. Therefore, revealing its climatological distribution and long-term variation is very important for disaster prevention and mitigation and climate change response. Based on the minute precipitation data collected at 2225 self-recording stations from 1965 to 2004 and 2435 automatic weather stations from 2005 to 2019 in China, the characteristics of climatological distribution and variation of minute precipitation in mainland China are analyzed. Results show that the minute precipitation frequency basically increases from north to south, and the precipitation intensity is smaller in Northwest China and larger in the eastern plains. Maximum precipitation at one-minute and five consecutive minutes mostly occurs in the Inner Mongolia and North China. Maximum precipitation at 10 consecutive minutes and longer as well as annual average maximum precipitation that lasts over different periods mostly occur in the coastal areas of South China. Minimum precipitation indices all are found in southern Xinjiang region. From 1965 to 2004 and from 2005 to 2019, the minute rainfall frequency increased in summer, which is the main reason for the increased national average summer precipitation. Minute precipitation intensity had no obvious trend. Percentage anomalies of annual maximum precipitation in several minutes to one day all increased, among which continuous precipitation over the period of about half an hour increased fastest. Overall, minute precipitation did not tend to become extreme, and the increased extreme precipitation can be mainly attributed to the increase in the duration of heavy rain process.

     

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