基于芝加哥算法的河北省四城市短历时暴雨极值特点分析

摘要

Using the minute resolution rainfall data at Tangshan, Qinhuangdao,Baoding and Xingtai meteorological stations in Hebei prov-ince from 1961 to 2014, the annual maximum rainfall on 120 min duration is statistically analyzed, and the classification of rainfall pattern is performed with fuzzy identification method. The rainstorm pattern for 120 min duration of 2 years return period is determined at 4 meteorologi-cal stations by the Chicago method. The results show that (1) there is much difference of trend about annual maximum rainfall on 120 min du-ration. The fluctuation at Tangshan and Baoding is gentle, but at Xingtai is obviously rising with a climate tendency of 3.66 mm/10a. The num-ber of the ten maximum precipitation extremes is more in 1981—2014 than in 1961—1980. (2) The dominant temporal patterns of 120 min duration rainfall process at 4 observatories are single peak, and type I storm occurs most frequently, in which rainfall concentrated early in the storm, followed by type III. Bimodal and uniform process occurred less frequently. (3) All the rainstorm pattern on 120 min in the 4 observato-ries as revealed by the Chicago method presents a single-peak pattern. The distribution characteristics of rainfall process present an increase early in the storm, then a decrease, and rainfall concentrates during its peak moment. Baoding's peak moment appears early, and Qinhuangd-ao's peak is late. The rainfall peak of rainstorm pattern by the Chicago method on 120 min is located before 1/3 over the whole rainfall period in Baoding and Tangshan, while those for Qinhuangdao and Xingtai are lagging.%利用河北省唐山、秦皇岛、保定和邢台4个气象站1961-2014年逐分钟降雨资料,对历时120 min的年最大降雨量进行统计分析,采用模糊识别法对降雨过程进行分型,并通过芝加哥法推求出4个测站重现期2 a历时120 min的暴雨雨型.结果表明:(1)各站120 min年最大降雨量的多年变化趋势存在较大差异,其中唐山和保定两站的波动较为平缓,邢台站呈明显上升趋势,其气候倾向率最大;各站多年最大降雨量的极大值出现在1981-2014年间的个例数明显多于1961-1980年,且雨量的极端最大值均出现在1985年以后.(2)模糊识别法得到各站120 min历时降雨过程均以单峰峰值居前型为主,单峰峰值居中型次之,双峰雨和均匀型降雨过程的发生频率较低.(3)芝加哥法推求的各站历时120 min暴雨雨型均为单峰型,降雨过程的整体呈现先增大后减小的分布特点,雨峰时刻的降雨量和雨强最大,其中保定站雨峰出现时间最早,秦皇岛站最晚,保定和唐山两站的雨峰位置均超前整个降雨过程的1/3分位,秦皇岛和邢台站的则略有滞后.