1961—2017年郑州夏季降水日变化规律分析

Precipitation Diurnal Variation in Summer in Zhengzhou from 1961 to 2017

利用郑州气象站1961—2017年逐小时降水资料,采用平均小时降水量、降水频次、降水强度、降水贡献率、降水发生率、降水历时及强降水等级等指标,分析了57年郑州夏季6—8月降水日变化规律.结果表明:①郑州夏季降水量和降水强度的日变化表现出明显的凌晨、傍晚和上午10时“三峰”结构,主峰出现在傍晚18时;而降水频次表现出凌晨1时至上午9时的单峰结构.②夏季降水量和降水强度日变化在上午10时呈现的峰值是由8月份降水贡献的,6-7月在该时段并未表现峰结构.③郑州各历时降水发生率随降水历时的增加呈对数递减趋势,而贡献率则呈先降低后增加的趋势.④郑州降水以1~5h短历时为主,频发于傍晚和清晨前后,贡献率则以7~24h历时为主,频发于凌晨下半夜至早晨.⑤强降水频发于凌晨和傍晚,三级频次最多,二级次之,一级最少;降水贡献率则相反.

Based on the hourly precipitation data from 1961 to 2017,the diurnal variation of precipitation in summer in Zhengzhou meteorological station during the recent 57 years was analyzed using the following indexes, such as the average hourly precipitation amount,the precipitation frequency,the precipitation intensity,the precipitation contribution rate,the precipitation occurance rate,the precipitation duration and the heavy precipitation grade. The results showed as follows.① The diurnal variation of precipitation and precipitation intensity in summer in Zhengzhou meteorological station showed three obvious peaks at dawn,dusk and 10:00. The main peak appeared at 18:00 at dawn. The precipitation frequency showed a single peak from 1:00 to 9:00.②The peak value of the daily variation of precipitation amount and precipitation intensity at 10:00 in summer was contributed by the precipitation in August. There were not obvious peaks’structure in June and July.③The precipitation incidence logarithmicaly decreased with the increase of precipitation duration. The precipitation contribution rate decreased at first and then increased in Zhengzhou meteorological station.④The precipitation mainly lasted from 1 hour to 5 hours which frequently occurred at dusk and dawn. The precipitation contribution rate mainly resulted from the duration of 7-24 hours which frequently occurred from the dawn to the morning.⑤The heavy precipitation always occurred at dawn and dusk. The most frequent was in the third level,followed by the second level and the least in the first level,while the contribution rate was opposite.