河南区域暴雨时空分布特征

Temporal-spatial Distribution Characteristics of Rainstorms in Henan Province

摘要:

利用1970—2021年河南逐日降水数据，通过数理统计、线性趋势及聚类分析等方法，对河南区域暴雨日的时间演变特征和落区进行统计与分型。结果表明：52 a河南共出现650个区域暴雨日，年均12.5 d；夏季出现次数最多，共计484 d，占总日数的74.5%，冬季无区域暴雨发生。区域暴雨日数、强度、发生初日和终日的总时间序列及均值突变点前、后期的子序列均无显著变化趋势。2008—2021年年均区域暴雨发生初日明显提前，终日明显延后；暴雨落区可分为豫北、豫中、豫南和河南全省4类空间分布型。各站区域暴雨平均日数、暴雨强度和极值雨量的低值中心主要位于豫西山区，大值中心集中在驻马店地区；大多数站点区域暴雨强度大于非区域暴雨强度；区域暴雨中各台站暴雨最长持续日数集中在2～3 d。

Abstract:

Using daily precipitation data in Henan from 1970 to 2021, this study employed mathematical statistics, linear trend analysis and cluster analysis to assess and classify the temporal evolution characteristics of regional rainstorm days and the spatial distribution of rainstorm regions in Henan. The results show that a total of 650 regional rainstorm days occurred in Henan over the 52-year period, with an annual average of 12.5 days. The highest frequency of rainstorms was recorded in summer with 484 days, accounting for 74.5% of the total, while no regional rainstorms were recorded in winter. There was no significant trend of change in the total time series and the sub-series before and after the mean mutation point of regional rainstorm days, rainstorm intensity, first occurrence day, and last occurrence day. From 2008 to 2021, the average first occurrence day of regional rainstorms significantly advanced, while the last occurrence day was noticeably delayed. The rainstorm falling regions can be categorized into four types: northern Henan, central Henan, southern Henan and whole Henan. The average number of regional rainstorm days, the rainstorm intensity, and low-value centers of extreme rainfall were mainly located in the mountainous areas of western Henan, while high-value centers were concentrated in Zhumadian.The intensity of regional rainstorms was greater than that of non-regional rainstorms at most meteorological stations.During regional rainstorms, the longest duration of rainstorms at each station primarily spanned between 2-3 days.