摘要
运用回归分析法、小波分析、M-K突变分析,对西安站近55a的降水变化进行了分析。结果表明:近55a来,西安降水量呈波动变化过程。受大气环流的影响,西安地区的降水与西北地区东部的降水变化一致,春季、夏季、秋季降水量都在下降,冬季降水在波动中有明显增加趋势;秋季降水与El Nino、La Nina之间存在一定的关系,冬季降水量增加显著与西风势力增强和南来水汽增多有很大的关系;3a、6a左右时间尺度在55a中始终存在,且周期振荡稳定。突变分析表明西安的降水在20世纪60年代和90年代左右有显著的突变点存在,即发生了明显的两次突变,两次突变都是由多雨期到少雨期。
Based on precipitation data of Xi＇an from 1951 to 1995, changes of the precipitation over last 55 years in Xi＇an City were analyzed, by using methods of linear regression, moving average, wavelet analysis and M-K mutation analysis. The results showed that the precipitation generally experienced fluctuation process in Xi＇an over last 55 years. The precipitation changes in Xi＇an were accorded with the precipitation changes in the eastern parts of the Northwest China under the impacts of the atmospheric circulation. The precipitation decreased in spring, summer and au- tumn, while it had an increasing trend with the fluctuations in winter. The precipitation in autumn had a certain relationship with the E1 Nino and the La Nina. A significant increasing trend of the precipitation in winter was greatly related to the enhanced west force and increased water vapor from south. The period of the precipitation change with steady periodic surge was three years and six years over last 55 years. The mutation analy- sis showed that the precipitation in Xi＇an both in 1960＇s and 1990＇s had a significant mutation point, where it was into less rain period from more rain period.
出处
《中国农业气象》
CSCD
2008年第4期406-410,共5页
Chinese Journal of Agrometeorology
基金
教育部人文社会科学研究基地重大招标项目(05JJD770014)
中科院地球环境研究所项目(SKLLQG0705)
关键词
降水量变化
小波分析
突变分析
Precipitation change
Wavelet analysis
Mutation analysis
