1970-2014年长江流域极端降水过程的时空变化研究

Spatio-temporal Variations of Extreme Precipitation Events in Yangtze River Basin during 1970-2014

基于长江流域131个气象站数据,利用Mann-Kendall非参数检验、主成分分析及R/S分析等方法分析了长江流域极端降水的时空变化特征。结果表明:(1)主要强降水指数变化均呈现增加趋势。20世纪70年代主要极端降水指数呈持续下降趋势,20世纪80年代、90年代和2000年以后降水指数变化趋势年代差异增大,稳定性差。(2)强降水在太湖流域、鄱阳湖流域大部分地区和洞庭湖流域的下游地区呈显著增加。(3)除了弱降水指数外,各极端降水指数之间具有显著的相关性。(4)长江流域降水的主要特点在于弱降水变化不显著,强降水变化幅度较大,降水过程不稳定,容易发生洪涝灾害。

Based on the data from the 131 meteorology stations in the Yangtze River Basin, the study was conducted by using the Mann -Kendall nonparametric test, principal component analysis and R/S analysis, to reveal the spatial and temporal variation characteristics of the extreme precipitation in the Yangtze River Basin. The results indicate （1） The main extreme precipitationindices showed a trend of increase during 1970-2014, the main extreme precipitation index showed a lasting trend of decline afterthe 1970s while bigger and more unstable decade-on-decade variations should be noted since the 1980s. （2） The most part PoyangLake Basin and the downstream area of the Dongting Lake face the increased heavy precipitation. （3） Also there is a goodcorrelation between the extreme precipitation index which all pass the 0.05 significance level test, except for the weak precipitation indices. （4） The main characteristics of the Yangtze River Basin precipitation is the barely noticeable change of weak precipitation, vast change for extreme precipitation change, unstable precipitation process and the high risk of flood.