小时和日值降水数据对河南省暴雨日数和暴雨日变化特征的影响

The influence on rainstorm days and rainstorm diurnal variation of the hourly and daily precipitation dataset in Henan Province

利用1961—2018年河南省111个气象站逐日和逐小时降水数据,分析了暴雨日数的时空变化规律及暴雨日变化特征,并通过统计对比分析,评估了小时和日值降水数据对暴雨日数及暴雨日变化的影响。结果表明:(1)1961—2018年,河南省年平均暴雨日数变化呈显著上升趋势,速率为0.34 d·(10 a)^(-1);94.6%的气象站点年平均暴雨日数的气候倾向率为正,显著增加的站点数占总站数的73.0%;年平均暴雨日数为1.4 d,以7月最多,平均值为0.52 d,占年平均暴雨日数的37.1%。(2)1961—2018年,河南省暴雨总降水的日变化呈现单峰结构,主峰值出现在05时,为4.5 mm;暴雨日变化峰值呈波动下降趋势,速率为0.16 mm·(10 a)^(-1);日变化峰值大部分出现在00—08时,共42个年份,占79.3%;从空间分布看,各气象站点的暴雨日变化峰值大都出现在00—06时,占总站数的73.5%。(3)2014—2018年,河南省小时和日值降水数据吻合度为100%;吻合暴雨总降水的日变化的主峰值和次峰值出现在04时和17时,分别为4.3 mm和3.4 mm;日变化峰值出现在13—18时的气象站点最多,占总站数的33.9%。(4)小时和日值数据对暴雨日数及暴雨日变化造成了影响,主要表现在年平均暴雨日数及其变化趋势不一致和暴雨日变化的差异。

Based on the daily and hourly precipitation dataset of 111 meteorological stations in Henan Province from 1961 to 2018,the spatial and temporal variation characteristics of rainstorm days and the characteristics of the rainstorm diurnal variation were analyzed.Through statistical comparative analysis,the influences on rainstorm days and rainstorm diurnal variation of the hourly and daily precipitation dataset was evaluated.Results are as follows:(1)during 1961-2018,the annual mean rainstorm days in Henan Province shows a significant upward trend,with a rate of 0.34 d·(10 a)^(-1).94.6%of meteorological stations in the province have a positive climatic tendency for the annual mean rainstorm days,and the significantly increased number of stations accounted for 73.0%of the total number of stations.The mean rainstorm days per year is 1.4.July has the most rainstorm days,with a mean of 0.52 day,accounting for 37.1%of the annual mean rainstorm days.(2)During 1961-2018,the diurnal variation of the rainstorm total precipitation in Henan Province presents a single-peak structure,with the main peak value appearing at 05∶00 BST,which is 4.5 mm.The diurnal variation peak of rainstorm shows a fluctuating downward trend,with a rate of 0.16 mm·(10 a)^(-1).Most of the diurnal variation peaks occurs between 00∶00 BST and 08∶00 BST,which has 42 years,accounting for 79.3%of total years.From the perspective of spatial distribution,the diurnal variation peaks of rainstorm in meteorological stations occurs between 00∶00 BST and 06∶00 BST,accounting for 73.5%of the total meteorological stations.(3)During 2014-2018,the agreement of hourly and daily precipitation dataset in Henan Province is 100%.The main and secondary peak value of anastomotic rainstorm appears at 04∶00 BST and 17∶00 BST,4.3 mm and 3.4 mm respectively.Most of the peak of the diurnal variation occurs between 13∶00 BST and 18∶00 BST,accounting for 33.9%of the total stations.(4)The rainstorm days and rainstorm diurnal variation are affected by hourly and daily dataset.The main performance is the annual mean rainstorm days and its variation trend are not consistent and also the difference of the rainstorm diurnal variation.