松辽流域近50年来降水演变规律分析

Evolution Rule of Precipitation in the Song-Liao Basin in Recent 50 Years

采用传统统计分析方法和小波分析方法,分析了松辽流域1956—2006年的降水量演化规律及其未来的演变趋势。结果表明:松辽流域年降水量呈整体下降趋势,主要原因为每年8—9月、20世纪70年代及21世纪初降水量均大幅下降;流域年降水量基本呈现30 a左右和12 a左右丰枯交替的周期变化,且枯水期相对较长;估计未来6～10 a,松辽流域绝大部分区域将逐渐进入下一个多雨阶段。

This article adopted the traditional statistical analysis method and the wavelet analysis method to analyze the evolution rule of precipitation series and evolution trend of the future of the Song - Liao Basin from 1956 to 2006. The results show that precipitation has a decreasing tendency in the Song - Liao Basin and that mainly caused by a sharply decreasing of precipitation in August and September of each years, 1970s and the be- ginning of the 21st century. Precipitation shows a transferring tendency between abundant and drought, and drought stage maintains a longer time than corresponding abundant water stage. We can estimate the future changes in 6 - 10 years of Song - Liao Basin, and most of the area will get into the next rainy stage.