摘要
为了揭示流域汛期降雨变化的多时间尺度的复杂结构，采用Morlet小波函数。对东江流域1956。2005年汛期降雨时间序列进行了小波分析，找出了不同时间尺度下降雨序列变化的周期和突变点，并根据降雨主周期对未来汛期降雨变化进行了预测。研究结果表明，汛期降雨序列呈现微弱的减少趋势，倾向率为每10a 12．08mm，近50a汛期降雨量减少了约60．4mm；汛期降雨量变化的特征时间尺度为2、4、7、12a与19a，其中4、7a左右的周期振荡最强，为汛期降雨量变化主周期；依据主周期的变化趋势，预测2006年前后东江流域汛期降雨将偏少，在2008—2010年汛期降雨将偏多。
Based on the monthly and annual rainfall data of more than 50 rainfall stations from 1956 to 2005 in the Dongjiang River Basin, we have analyzed the spatial structure and changes of rainfall and the multi - time scales characteristics of rainfall during flood season in the past 50 years using Morlet wavelet function. The periodic oscillation of rainfall variation in flood season and the points of abrupt change at different time scales along the time series are discovered and the main periods of every serial are confirmed. It is showed that the distribution of rainfall during flood season in the Dongjiang River Basin has obviously regional difference, which is influenced not only by the weather system but also by the geographical environment such as topography, etc ; and there exists obvious periodic oscillation for the rainfall variation in flood season. The localization characteristics of time - frequency for wavelet analysis can demonstrate the detailed structures of rainfall. The wavelet analysis can be an alternative approach to analyze climate multi -time scales characteristics and forecast short -term climate variations.
出处
《人民长江》
北大核心
2010年第2期52-55,共4页
Yangtze River
基金
河海大学水文水资源与水利工程科学国家重点实验室开放研究基金资助项目(2008490511)
国家自然科学基金重点项目(50839005)联合资助
关键词
汛期降雨
变化特征
小波分析
东江流域
rainfall in flood season
variation characteristics
wavelet analysis
Dongjiang River Basin
