四川盆地降水集中指数年代际突变分析  

Decadal Abrupt Change of Precipitation Concentration Index in the Sichuan Basin

作　　者：曾维尧 向卫国[1] 

机构地区：[1]成都信息工程大学大气科学学院高原大气与环境研究中心,四川成都610225

出　　处：《成都信息工程学院学报》2015年第6期616-620,共5页Journal of Chengdu University of Information Technology

基　　金：国家公益性行业(气象)科研专项资助项目(GYHY201306059)

摘　　要：为探究四川盆地年降水量集中度的变化问题,利用CN05.2降水观测资料,考察1961-2010年四川盆地降水集中指数的时空分布,并通过滑动T检验法分析四川盆地降水集中指数（PCI）的年代际波动特征。结果表明四川盆地PCI值介于12-17,降水具有季节性集中的特征;大值中心位于盆地西北部,盆地西部的PCI值明显大于盆地东部。四川盆地PCI在近50年呈现出并不显著的减小趋势,具有明显的年际和年代际变化特征。四川盆地东部和西部在1961-2010年几乎同时出现了2次年代际突变,分别出现在20世纪70年代末和80年代末。干湿季降水的反位相变化引起了四川盆地PCI的这2次年代际突变,年内降水月分配的变化问题值得引起关注。To explore annual precipitation concentration in Sichuan basin,based on CN05. 2 observational precipitation datasets,this study investigates the spatial and temporal characteristics of precipitation concentration index（ PCI） and examines the interdecadal fluctuation of PCI by the running t-test with a 10-yr sliding window during 1961- 2010. PCI is between 12- 17 in Sichuan basin,where annual precipitation shows a feature of seasonal concentration. The max PCI center is around northwestern basin and the PCI value in west part of Sichuan basin is bigger than that in east part. The PCI time series shows an insignificant decreasing trend with obvious interannual and interdecadal changes in the last 50 years. Furthermore,there are two decadal abrupt changes of PCI in west part of Sichuan basin during 1961- 2010,which occur in the late 1970 s and 1980 s,respectively. It is the same in east part. The two decadal abrupt changes of PCI is caused by anti-phase variation of dry-and wet-season precipitation. Hence,monthly distribution of annual precipitation is worthy of attention.

关 键 词：气象学 降水 四川盆地 降水集中指数 年代际突变 

分 类 号：P467[天文地球—大气科学及气象学]