太湖流域61年来降水时空演变规律分析

Tempo-spatial Change of Precipitation in Taihu Lake Basin during Recent 61 Years

基于太湖流域1951～2011年长系列降水资料,采用正交函数分解法、Spearman和Mann-Kendall非参数统计检验法、连续小波分析方法等,从空间分布、趋势性、周期性和突变性等方面系统剖析了61年来太湖全流域及各水利分区降水的时空演变规律。结果表明,太湖流域降水表现为两种空间分布类型,一类是年降水量振幅高值中心位于以市岭站为中心的浙西山区以及湖西区的长兴～宜兴一线,第二类表现为年降水量以湖区为分界呈南北相反的分布型态。61年来,太湖全流域和各水利分区年降水量、汛期降水量及年最大30日降水量均不存在显著的变化趋势,但具有较明显的丰枯周期。本文研究结果可为流域开展洪水资源利用、制订调度方案、应对气候变化提供科学依据。

Based on precipitation observation in the Taihu Lake Basin during 1951-2011, the tempo-spatial changes of the precipitation over this area were systematically analyzed in spatial distribution, time trends, periodicity and mutation, by using the methods of empirical orthogonal function decomposition （EOF）, Mann-Kendall and Sperman＇s test and wavelet analysis. By EOF, the annual precipitation fields in the study area were of two main spatial modes, namely the west-east and south-north modes. In the last 61 years, the flood season precipitation and maximum precipitation within continuous 30 days over the whole basin and its seven sub-areas had no substantial trends. However, their periodicity is remarkable. The results of this paper provide important references for flood utilization, flood regulation scheme development and climate change adoption for the Taihu Lake Basin.