Based on hourly precipitation data from 101 stations in Henan Province from April to Oc-tober in 1992-2021 and terrain information,the spatio-temporal evolution of short-time heavy rainfall of different grades and their relationship with terrain are analyzed in this paper.The results show that:(1)The frequency of short-time heavy rainfall(R1h≥20 mm·h-1)and the three different grades of short-time heavy rainfall are all distributed in the pattern of more in the east and less in the west of Henan Province.The frequencies and[20 mm·h-1,50 mm·h-1)of short-time heavy precipitation are more in the south and less in the north.The short-time heavy precipitation with[50 mm·h-1,80 mm·h-1)has a small difference in occurrence frequency between the north and the south,while the precipitation of[80 mm·h-1,+∞)is often seen less in the south but more in the north.The monthly short-time heavy pre-cipitation is characterized by the frequency appearing more in the east and less in the west,with a slight difference between the north and the south in July,August and October,and more in the south and less in the north in the other months.(2)The inter-annual variation of short-time heavy precipitation is very dif-ferent,and the monthly variation is unimodal.Late June to early August is the period to have frequent short-time heavy precipitation of all grades.(3)The diurnal variation distribution of short-time heavy pre-cipitation frequency shows a bimodal pattern,with the highest frequency appearing at 16:00 and 21:00,then at 00:00 and 05:00,and the lowest frequency at 09:00 and 14:00.The diurnal variation of short-time heavy precipitation frequency from June to August is bimodal,and such features are not obvious in other months.From April to October,the stations to see daily peak value of short-time heavy precipitation are the most at 16:00 and 21:00,followed by that at 00:00 and 05:00.The spatial distribution is large in the east and south but small in the west and north.The largest number of stations with daily peak value of precipitation appears at 00:00 and 05:00 and then at 16:00 and 21:00 each month.(4)The propor-tions of maximum rainfall intensity and short-time heavy rainfall amount both present the distribution fea-ture of high in the east and north but low in the west and south.(5)The spatial distribution of short-time heavy rainfall,the spatial distribution of daily variation,the high value area of maximum rainfall intensity,and the proportion of short-time heavy rainfall are all closely related to the topography of Henan Province,and the topography has an effect of increasing or decreasing short-time heavy precipitation.
关键词
短时强降水/分级/地形/统计特征
Key words
short-time heavy rainfall/classification/topography/statistical characteristics
维普
万方数据