1953—2017年阜阳市短时强降水特征分析

Analysis on characteristics of short-time heavy rainfall from 1953 to 2017 in Fuyang

利用阜阳市6个国家站1953-2017年逐小时降水量数据,统计分析阜阳市短时强降水的年际、月际以及强度、空间分布变化特征。结果表明:(1)6站多年平均短时强降水频次为每站4次,以20mm/h的短时强降水发生频率为最多。(2)短时强降水月际分布中7月最多,其次8月,再次6月;4个等级的短时强降水中,除80mm/h的短时强降水8月最多外,其余3个等级均是7月最多。(3)短时强降水在逐时分布上显示为双峰型特征,峰值在早晨前后和傍晚前后,最大峰值早晨与傍晚相当。4个等级的短时强降水中,除80mm/h的短时强降水外,随着短时强降水强度的提升,其最大峰值由早晨向傍晚转移。(4)不同月份短时强降水的逐时分布显示,雨季夜雨(早晨)明显,6、7月为汛期雨季,9月为淮河秋雨。(5)短时强降水发生频率和极端雨强都呈现出上升的年代际变化特征,极端雨强上升趋势尤为明显。

Based on the hourly observed data from weather stations in Fuyang from 1953 to 2017,the short-time heavy rainfall were analyzed on the spatial,annual,monthly,temporal and strength change characteristics.The re?sults show that:(1)the average annual short-time heavy precipitation frequency in 6 stations is 4 times in each sta?tion,with the frequency of 20mm/h being the largest.(2)the monthly distribution of short-time heavy rainfall is the largest in July,followed by August and June.Among the four grades of short-time heavy precipitation,except the 80mm/h short-time heavy precipitation in August,the other three grades are the most in July.(3)short-time heavy rainfall shows a bimodal pattern in the hourly distribution,with the peak value around morning and evening.Among the 4 grades of short-time heavy precipitation,except the short-time heavy precipitation of 80mm/h,the maximum peak value of the short-time heavy precipitation changes from morning to evening with the increase of its intensity.(4)the hourly distribution of short-time heavy rainfall in different months shows that night rain is obvious in rainy season..(5)both the occurrence frequency of short-time heavy precipitation and extreme rain intensity show the characteristics of increasing decadal variation,especially the increasing trend of extreme rain intensity.