近48年贵州暴雨日数及降水总量的变化特征研究

 利用贵州81个台站1963—2010年的逐日降水资料，采用一元线性回归、五年滑动平均、EOF分解、相关分析、Morlet小波变换对贵州48年暴雨日数及降水量进行统计分析,并对二者不同的变化趋势作了对比分析.结果表明：①暴雨日数与年总降水量关系密切，暴雨日数与年降水总量在2—4年上震荡周期明显，二者在此时间尺度上具有很好的凝聚共振关系，降水总量的变化略落后于暴雨日数的变化;②暴雨日数及降水量在空间上均具有由南向北递减的特征，暴雨日数81个测站中有48个站的暴雨日数是增加的，而81个测站中有77个站的年降水总量降水趋势是减少的，二者在黔西南、遵义、毕节及黔南有较一致的减少趋势，而在其余地方二者为相反的变化趋势，且二者的前三模态空间分布上具有较一致的变化特征;③暴雨日数及降水量均具有多尺度变化特征，在月季尺度上，暴雨及降水量主要出现在5—9月，且各月变化幅度较大；在年代际尺度上，近48年贵州暴雨日数呈现一定的增加趋势，但是未通过显著性检验，而降水总量呈明显的下降趋势，通过了0.05的显著性检验.

Climate characteristics of the number of Rainstorm days and the total amount of Precipitation in Guizhou province

Based on the daily precipitation data from 81 station in Guizhou province from 1963 to 2010,the number of rainstorm days and the total amount of precipitation were analyzed by linear fitting、5-years smoothing、EOF、correlation coefficients and Morlet wavelet.The results are as follows:①The relation between the number of rainstorm days and the total amount of precipitation were intimate;The correlation coefficients in the Spatial and timely distributions passed the 0.05 significance level.the number of rainstorm days and the total amount of precipitation vibration were consistent,the variation from the number of rainstorm days was advanced than from the total amount of precipitation.② The number of rainstorm days and the total precipitation in south of Guizhou province were excessive in the south,48 station’s rainstorm day number is increased,but 77 station’s annual rainfall amount rainfall trendswas reduced,they had the consistent reduction in trend in Qianxinan,Zunyi、Bijie and Qiannan,while in the rest tendency was opposite ,the first three EOF eigenvector field of the number of rainstorm days and the total precipitation are consistent; ③The rainstorm and precipitation mainly occurred in May to September,and The number of rainstorm days’ internal variations were remarkable,the number of rainstorm days increased in the past 48 years,but the total precipitation decreased.