1961～2018年河南省暴雨初终日和暴雨日数的时空变化规律分析

利用1961～2018年河南省111个气象站逐日降水资料,采用气候倾向率、相关分析和多元逐步回归等数理统计方法,分析了河南省暴雨初终日和暴雨日数的时空变化规律。结果表明:(1)河南省各站平均暴雨初日为5月19～7月16日,最早暴雨初日为1月28日～5月25日,均由南向北明显推迟,由西向东明显提前,由平原向山区明显推迟。(2)河南省各站平均暴雨终日为8月5日～8月30日,最晚暴雨终日为9月9日～11月29日,均由南向北明显日期提前,由西向东明显推迟,由平原向山区最晚暴雨终日明显提前。(3)河南省各站年平均暴雨日数为0.7～4.3天,由南向北明显减少,由西向东明显增多,由平原向山区明显减少。(4)河南省平均暴雨初日和平均暴雨终日均有提前趋势,气候倾向率分别为1.2和0.2 d·(10 a)~(-1);平均暴雨日数呈阶段性变化,特别是2000年以后呈明显减少趋势;各站暴雨初日、暴雨终日和暴雨日数的气候倾向率分别在-9.3～9.3、-2.4～5.4和-3.0～3.2 d·(10 a)~(-1)之间,但仅有少数站点通过显著性水平检验。

Analysis on the Spatial-temporal Variation Characteristics of Beginning and Ending Date of Rainstorm and Rainstorm Days in Henan Province from 1961 to 2018

Based on the daily precipitation data from 111 meteorological stations between 1961 and 2018, the spatial-temporal variation characteristics of the beginning and ending date of rainstorm and rainstorm days in Henan Province were analyzed in this study using the mathematical statistics methods that included climate tendency rate, correlation analysis and multiple stepwise regression. The results showed as follows: (1)The average beginning date of rainstorm was from May 19 to July 16 and the earliest date of rainstorm was from January 28 to May 25 in Henan Province. Both of them were significantly delayed from south to north with the increase of latitude and from plain to mountains with the increase of altitude, but from west to east the date were significantly advanced due to the increase of longitude. (2) The average ending date of rainstorm was from August 5 to August 30 and latest ending date of rainstorm was from September 9 to November 29. Both of them were significantly advanced from south to north and delayed from west to east, the latest ending dates of rainstorm were significantly advanced from plain to mountains. (3)The average rainstorm days in Henan Province were 0.7-4.3 days, the days were significantly decreased from south to north and from plain to mountains and significantly increased from west to east. (4) As a whole, both the average beginning and ending dates of rainstorm in Henan Province showed an advanced trend, and the climate tendency rates were 1.2 d·(10 a)^-1 and 0.2 d·(10 a)^-1 , respectively; the average rainstorm days varied with year, especially after 2000, it presented an obvious decreasing trend; the climate tendency rate of beginning date, ending date and rainstorm days in each station were between -9.3-9.3 d· (10 a)^-1, -2.4-5.4 d· (10 a)^-1 and -3.0-3.2 d· (10 a)^-1, but only a few stations showed obvious trends.