四川盆地枢纽城市降水量变化趋势探究

Preliminary Study on Characteristics of Precipitation in the Central Cities of Sichuan Basin

采用信四川盆地中心地带4个枢纽城市监测站1951-2004年间降水资料,运用降水的趋势分析、Mann-Kendall检验方法、滑动t检验方法及小波分析方法对各站点降水量变化趋势进行趋势性分析及周期性分析,并进行突变检验以及相关性分析。结果表明：盆地中心城市全年降水量随时间呈下降趋势;重庆春夏两季和成都冬季降水小幅增加,其余均呈下降趋势。重庆降水在1964年突变,之后降水呈现上升趋势。成都在1964年和1990年发生两次突变,但是降水均是减小。南充发生过3次突变,仅在1982年后有小幅增加,之后降水减少。内江在也发生3次大的突变,1981年后降水量增加,其余时候降水均减少。重庆、成都、南充及内江站年降水变化主周期分别为3a、26a、19a及9a,同时四个站点变化相关性较差。

The evolution characteristics of precipitation at four typical monitoring stations in the center of Siehuan Basin have been analyzed and discussed by means of the Mann-Kendall method,slide t-test method and wavelet analysis according to series of observational data from 1951 to 2004.The results presents that the precipitation has a trend of decline with time, the precipitation of spring and summer in Chengdu and winter of Chongqing increase slightly, others have a decreased trend.The mutation moment of precipitation in Chongqing is in 1964,and after that there is an upward trend.There are two mutation moments in 1964 and 1990 in Chengdu,these both have a downward trend.Nanchong has three mutation moments,only after 1982 there has a slight upward trend,there is a downward trend.Neijiang also has three mutation moments,precipitation after 1981 increases slightly,there is a downward trend in other years.The main period of Chongqing,Chengdu, Nanchong and Neijiang respectively is 3a,26a,19a and 9a,meanwhile changes in control station have bad consistency.