基于小波与R/S方法的汉江中下游流域降水量时间序列分析

基于汉江中下游流域9个国家气象站1961～2006年的降水数据,综合采用Morlet小波分析、小波分解和R/S分析方法,对流域降水量周期和未来趋势进行分析及预测。研究结果表明:汉江中下游流域年降水量存在5年左右的短周期和10～15年的中长周期;部分气象站可能存在40年左右长周期,需要更长的时间序列验证。基于通过小波分解提取的历史降水量变化趋势,进一步结合R/S分析表明,汉江中下游流域降水量时间序列总体上存在比较明显的赫斯特现象,未来该流域面临较大的防洪压力。

Precipitation change in middle and lower reaches of Hanjiang River: Based on wavelet analysis and R/S analysis

Along with global warming,regional precipitation is predicted to make change.As a branch of the Yangtze River,the Hanjiang River has suffered from heavy flood disaster frequently in the past several decades,which caused great damage to local residents and ecosystems,and the dramatic precipitation change was thought to be the main driving force.Therefore,it is of great importance to conduct studies on the trend and period of precipitation so as to take measures to prevent flooding.Integrating the precipitation data during 1961-2006 from nine weather stations in middle and lower reaches of Hanjiang River,this paper analyzed the periodicity characteristics and changing trend of precipitation in the study area by the methods of Morlet wavelet analysis and R/S analysis(Rescaled Rangle analysis).The results of the wavelet analysis showed that,all the nine weather stations had quasi-periods of 5 years(short period) and 10-15 years(mid-long period).And a few of the stations,such as Wuhan,Tianmen and Zhongxiang,might have a quasi-period of 40 years,which needs a longer time series to prove.Considering the assured periods,the stations of Wuhan,Fangxian and Laohekou took the short period as the main period,with the others for the mid-long period.The results of R/S analysis showed that there was obvious HURST PHENOMENON in the time series of regional precipitation,which would be consistent with the changing trend of precipitation after the study period.