河南省雷暴日时空分布特征分析

Analysis on Temporal and Spatial Variation Characteristics of the Number of Thunderstorm Days in the Henan Province

选取1971—2009年河南省120个站点的逐日雷暴资料,利用数学统计分析和信息熵两种方法,对雷暴的时空分布特征进行了分析。结果表明:河南省雷暴日数空间分布呈山区多、平原少的显著特征;39 a来雷暴日数在波动中呈减少趋势,气候倾向率为-1.27 d/10 a;每年6—8月为雷暴活动旺盛期;雷暴活动在时间上的不确定性自西北向东南方向增强,自南向北减弱,而在西南东北方向和自西向东方向则没有明显的规律,总体上山区较强,平原较弱;1976年、1989年、2003年、2009年的雷暴活动空间分布较为均匀,1975年、1995年的雷暴活动空间分布较不均匀。

Using the thunderstorm data of 120 stations in Henan province from 1971 to 2009,the spatial-temporal variation characteristics of thunderstorms were studied by means of mathematical statistics and information entropy.The results show that the number of thunderstorm days is more in mountainous areas and less in plain regions;the annual number of thunderstorm days has a decreasing trend of-1.27 d/10 a;the thunderstorm concentrates with in the period from June to August;the uncertainty in the time of annual days of thunderstorm is increasing form northwest to southeast,reducing from south to north and does not have obvious rule from southwest to northeast and from west to east;as a whole,the uncertainty in the time of the thunderstorm is bigger in mountain areas and smaller in plain regions;the temporal and spatial variation of annual days of thunderstorm is smaller in the years of 1976,1989,2003 and 2009,and bigger in the years of 1975 and 1995.