广西秋冬季降水特征分析

Analysis on the Characteristics of Autumn and Winter Precipitation in Guangxi

关键词:  秋冬季  降水  小波分析  突变

Key words:  autumn and winter  precipitation  wavelet analysis  abrupt change

摘要:

利用1961年1月至2006年2月广西89个气象观测站的逐日降水数据,计算各观测站45a来的秋冬季降水时间序列,运用小波分析和Mann-Kendell非参数化统计检验方法,分析广西秋冬季降水的时空异常分布和变化特征。结果表明,广西秋季降水南多北少,近20a来降水量总体上趋于减少;冬季降水则东多西少,20世纪70年代初期开始出现趋于增多的突变,近15a来这种变化比较显著。广西秋冬季降水时间序列存在着较为明显的年代际和年际两个振荡周期。广西秋冬季降水的地域性差异较大,西部地区秋季降水逐渐减少的趋势较为明显,桂南秋季出现异常干旱的情况比较频繁,桂东北、桂西南的冬季降水明显增多。

Abstract:

Using the day-to-day precipitation data of 89 weather stations in Guangxi from Jan.1961 to Feb.2006,computing the autumn and winter precipitation time series of each meteorological observatory in the last 45a,the article conducts a statistical analysis on the season precipitation in Guangxi.The results indicate that the precipitation in the South overtakes that of the North,and the seasonal precipitation tends to decrease in last 20 years in autumn.On the other hand,the precipitation in the East overtakes that of the West,and there should be some abrupt-change since early 1970's that the precipitation trend is increasing significantly in winter.There also exists two typical oscillations in the season precipitation time sequence.The difference in regional precipitation is also significant in Guangxi.Regional precipitation tends to decrease obviously in autumn.Regional precipitation in the northeast and southeast tends to increase obviously in winter,and the severe autumn drought occurs continually in South areas in last decennary in Guangxi.