桓仁县暴雨时间分布特征

利用桓仁国家基本气象站1953~2000年降水观测资料,运用原始资料整编方法,经过逐步分级统计,对桓仁站暴雨随各年代、各年份、月、旬和逐日的时间分布特点进行了分析,找出桓仁暴雨洪水灾害时段及其集中高峰日期。结果表明,桓仁县一般性暴雨增多,暴雨到大暴雨在减少,大暴雨呈对称减少;桓仁县暴雨具有明显的年代际特征,1953~1980年为暴雨日数变化相对平稳时期,1981~2000年为暴雨日数变化不规律时期;7、8月出现暴雨日数最多,8月是暴雨成灾的高发关键期;7月15日~8月26日是桓仁县3种暴雨集中时期,同时又是汛期一次连续最大降水过程暴发之时,更是暴雨洪水成灾泛滥之时。

Temporal Distribution Characteristics of Heavy Rains in Huanren County

According to the precipitation observation literatures in national principal station of Huanren County in 1953-2000,temporal distribution characteristics of heavy rains in Huanren County in each day,month and year were analyzed by gradually classification statistics and raw data compilation method.Periods of flood and heavy rains in Huanren County were found out,as well as the peak date.Results showed that the general heavy rains enhanced;heavy rain to heavy rainstorm reduced;and heavy rainstorm decreased symmetricaly.Heavy rain in Huanren County showed significant interdecadal features.Daily change of heavy rain in 1953-1980 was at relatively stable period,that in 1981-2000 was at ir regular period.Number of heavy rain days was the most in July and August.And August was the critical high-incidence period of heavy rain.The general heavy rain,heavy rainstorm and heavy rain to heavy rainstorm concentrated mainly from July 15 to August 26 in Huanren County,which was also the time of storm flood disaster.