近60 a来增江流域降水时空变化特征及其趋势分析

基于增江流域17个雨量站1956—2015年的逐年降水数据，采用Mann－Kendall趋势分析法、 EOF经典正交分解、 Morlet小波分析等方法，分析了流域降水量的时空变化特征。并用层次聚类法对研究站点进行分类和分区，以研究60 a来降雨中心的移动轨迹。结果表明：①增江流域多年平均降雨量为2098．3 mm，呈现微弱下降趋势，1976年为突变点，1976年以后进入降雨偏少时期，主周期由原来的6 a及2 a突变为5 a。②60 a来流域东北部和西部呈现微弱的增加趋势，西北部至东南部一带呈现微弱的减少趋势。③ EOF分解展示了高值区与低值区分布，左右岸区域呈相反的分布形态。④1973—1975年及2010—2015年，高值区和低值区发生了移动。

Tempo-Spatial Changes of Characteristics and Tendencies of Precipitation in Zengjiang River Basin in Recent 60 Years

Based on the annual rainfall from 17 precipitation stations in the Zengjiang River Basin during 1956-2015, the tempo-spatial changes of characteristics and tendencies of precipitation of this basin are systematically analyzed by using the methods of Mann-Kendall , empirical orthogonal function decomposition( EOF) , and Morlet wavelet analysis.The stations are classified and partitioned by hierarchical clustering method to study the moving traces of the annual precipitation canters.The results show: (1) The average annual precipitation of Zengjiang River Basin during 1956~2015 is 2098.3mm.A trend of decreasing with the muta-tion in 1976 is showed, which causes the break of periodicity.(2)There is a slightly increasing trend in the area of northeast and west, and a decreasing trend in the northwest and southeast areas.(3) EOF has identified the high and low precipitation areas, and found the distribution patterns of the left and right rank of the river.( 4 ) The movements of annual precipitation centers have hap-pened during 1973-1975 years and 2010-2015 years.