菏泽市雷暴的发生规律分析

目的]研究菏泽市雷暴的发生规律及特点。方法]根据1971~2007年菏泽市八县一区的雷暴观测资料,建立四季和年雷暴出现次数的时间和标准差序列,分析雷暴的发生规律及分布特征。结果]菏泽市雷暴的出现次数由牡丹区向四周逐渐递减。雷暴次数的年际变化呈交替增减,总体无明显的变化趋势;年雷暴日数自西北向东南稳定性减小。雷暴发生主要集中在4~9月,季节性明显,7月最多,11、2月没有。雷暴具有明显的日变化特征,每天的15:00~2:00为雷暴活跃期。平均雷暴初日自西北向东南逐渐提早,平均雷暴终日自南向北逐渐推迟。结论]该研究为菏泽市的防雷减灾提供了重要依据。

Analysis on the Occurrence Law of Thunderstorm in Heze City

Objective] The purpose was to study the occurrence law and characters of thunderstorm in Heze city.Method] Based on the observation data of thunderstorm of 8 counties and 1 district in Heze city from 1971 to 2007,the time and standard difference sequences of seasonal and annual occurrence number of thunderstorm were established and its occurrence law and distribution characters were analyzed.Result] The occurrence number of thunderstorm in Heze city gradually reduced around from Mudan area.The thunderstorm number showed flutuation in annual change and had no significant changing trend generally.The annual thounderstorm days reduced steadily from northwest to southeast.The thunderstorm occurrence mainly concentrated in Apr.to Sep.and had significant seasonality,and it was most in Jul.and none in Jan.and Dec.The thunderstorm had significant daily variation characteristics and 15:00-2:00 in every day was its active period.The averagely initial thunderstorm day became earlier from northwest to southeast and its averagely ending day became later from south to north.Conclusion] The study supplied important basis for the thunder prevention and disaster reduction in Heze city.