摘要
基于2013—2022年国家站和区域站逐时降水观测资料,以99.5%分位值作为河南省暖季极端小时强降水阈值,对其发生频次、降水强度及极值等进行研究。结果表明:河南省暖季极端小时强降水阈值主要集中在30~50 mm, 50 mm以上落区位于豫北及豫中东地区。极端小时强降水强度表现为豫北豫东大、豫西小,高值区位于豫北太行山东麓及豫中东平原,发生频次西多东少,区域站比国家站更能反映极端小时强降水的极端性、离散性和局地性。年变化趋势上极端小时强降水频次增多,强度减弱,极值变化不明显。月变化上频次、强度和极值均呈单峰分布,国家站和区域站频次表现类似,峰值均在7月;而两者在强度和极值上差异较大,国家站峰值分别位于6月和7月,区域站峰值则位于7月和8月,且区域站极端小时降水强度和极值均大于国家站。极端小时强降水频次、强度与极值日变化均为典型双峰结构,峰值分别位于午后至傍晚和夜间至凌晨,其中7—8月极端小时强降水频次双峰型结构最为明显。
Based on the hourly precipitation data of national and regional stations from 2013 to 2022,the frequency,intensity and extreme value of extreme hourly heavy precipitation in Henan province during the warm season were studied by taking the 99.5%percentile as the threshold.The results show that the threshold of extreme hourly heavy precipitation in Henan province during the warm season is mainly concentrated in the range of 30~50 mm,while the threshold above 50 mm is mainly located in the northern and the middle eastern parts of Henan province.The intensity of extreme hourly precipitation is large in the east and north Henan province while small in the west,and the high value areas are mainly located in the eastern Taihang Mountain and the plains in east central Henan province.The frequency is more in the west and less in the east.Compared with national stations,regional stations can better show the extreme,discrete and localized nature of extreme hourly precipitation.In terms of annual variation trend,the frequency increases,the intensity decreases,while the change of extreme value is not obvious.In terms of monthly variation,the frequency,intensity and extreme value exhibit a single-peak distribution.National and regional stations are similar in frequency with peaks in July,while different in intensity and extreme value with peaks of national stations in June and July,with peaks of regional stations in July and August respectively.Moreover,the intensity and extreme value of regional stations are larger than those of national stations.The diurnal variation of frequency,intensity and extreme value shows a typical bimodal structure,with one peak located from afternoon to evening and another one located from night to early morning respectively,which is most obviously in July and August.
作者
武威
段中夏
谢琼娜
WU Wei;DUAN Zhongxia;XIE Qiongna(Luohe Meteorological Service,Luohe 462300,China;Xinxiang Meteorological Service,Xinxiang 453000,China)
出处
《气象与环境学报》
2024年第5期20-29,共10页
Journal of Meteorology and Environment
基金
河南省气象局面上项目(KM202242)资助。
关键词
暖季
极端小时强降水
阈值
频次
Warm season
Extreme hourly precipitation
Threshold
Frequency
