辽宁省近50年降水量的突变特征及变化趋势分析

首先采用Pettitt方法对辽宁省21个气象站1958年一2008年51年的降水量序列进行突变分析，结果显示54476和54486两测站的年降水量序列分别在1996年和1998年存在显著的突变且通过了显著性水平检验，其它测站的降水量序列均未检测出显著的突变年份。根据累积距平曲线分析辽宁省51年的年均降水量在时间尺度上大致分为三个阶段：1958年一1975年为降水量增加阶段，1975年一1996年为降水量稳定阶段，1996年一2008为降水量减少阶段。最后应用Morlet小波分析对辽宁省年均降水量进行周期分析，结果表明降水在大尺度时间上存在约24年的周期震荡，在小尺度时间上存在约9年的周期震荡。

Change Points and Variation Tendencies of Precipitation in Liaoning Province over Past 50 Years

More attention has been paid to change point analysis in the areas of climate and hydrology due to its increasingly important role in indicating climate change or human activities. In this study, annual precipitation change points during 1958 - 2008 were collected from 21 meteorological stations in Liaoning province by using Pettitt method. This method can not only detect locations of the change points, but also judge whether a change point is significant or not at a certain significance level. Results show that monitoring station No. 54476 and No. 54486 detected change points in annual precipitation in 1996 and 1998, respec- tively, and the detected change points were remarkable at a 0. 05 significance level. There was no change point found at the other stations, which means that the magnitude of changes in the annual precipitation was not significant. In terms of the results of cu- mulative departure curves, the precipitation in Liaoning Province increased during 1958 to 1975, stabilized during 1975 to 1996 and reduced during 1996 to 2008. Morlet wavelet methods were used to analyze the annual precipitation in Liaoning Province. The results showed that the fluctuation period of annual precipitation varies between 9 years and 24 years in Liaoning Province.