近百年武汉市主汛期降水特征分析

THE CHARACTER OF SUMMER RAINFALL VARIATION OF WUHAN CITY DURING RECENT 95 YEARS

本文对武汉市1906—2000年主汛期（6—8月）的降水量资料进行了分析。结果表明,近百年来武汉市有两个旱涝事件多发时段,出现在30年代中期以前和60年代以后。主汛期降水量气候基本态在20世纪经历了高、低、高、低、高5个阶段,目前处于高基本态高变率时段。还利用小波变换揭示出了武汉市近百年来主汛期降水的多时间尺度特点,分析了其主要周期振荡和突变特征。指出武汉市主汛期降水存在40年、25年、10年、4—7年左右的周期振荡,并由降水的周期性推知本世纪初武汉市汛期将进入下一个少雨时段。

In this paper, the summer rainfall of Wuhan city during recent 95 years are investigated. It is shown that the dry-flood events occur frequently in the periods before the middle part of the thirties era and after the sixties. The climate fundamental state of flood -season rainfall has gone through high-low-high-low-high 5 stages, and now it is high climate fundamental state with high variability. Furthermore, the main periods of Wuhan summer rainfall and its catastrophe character during recent 95 years are studied by using the wavelet transform method. The main period about 40,25,10 and 4-7 years are found. Based on this, we can forecast the lack of rainfall in Wuhan city in initial stages of this century.