长江流域年平均气温的时空变化特征

ANALYSIS OF SPATIAL AND TEMPORAL CHARACTERISTICS OF ANNUAL TEMPERATURE IN THE YANGTZE RIVER BASIN

利用长江流域146个气象站点1960-2005年的逐年气温资料，选用EOF和REOF方法识别长江流域年平均气温空间变化特征，并对长江流域年平均气温变化敏感区域进行时间演变分析和突变检测。研究表明：长江流域年平均气温主要有2种空间振荡型（即全流域气温变化趋向一致型和流域内气温变化存在东西向差异型），3个变化敏感区域（长江流域中下游地区、长江流域南部和金沙江流域）。3个变化敏感区域的年平均气温都在20世纪90年代明显升高，且均在90年代后期呈突变增加，其中金沙江流域升温趋势最为明显，气候倾向率为0．20℃／10a。全流域1991～2005年年平均气温距平空间分布表明，自1991年以来全流域都为升温趋势，其中长江流域中下游地区和金沙江流域是升温幅度最大的地区。

Based on daily temperature data of 146 meteorological stations from 1960 to 2005 in the Yangtze River basin,this paper analyzed the spatial characteristics of annual temperature in the Yangtze River basin by applying EOF and REOF, and calculated temporal evolution and detected abrupt change. The results showed that,there were two main spatial oscillation patterns（the same trend in the whole basin and East- West difference trend in the whole basin） ,and three sensitive areas of annual temperature change（the Middle-lower basin,Southern Yangtze River basin and Jinshaiiang basin）. Annual temperature increased dramatically since 1990 in all the three areas,and showed abrupt changes in late 1990 s,while Jinshajiang basin increased most with climate trend rate 0.20℃/10a. Spatial distribution of 1991~2005 anomalies in the Yang-tze River basin also showed that annual temperature increased in the whole basin, especially the Middle-lower basin and Jinshajiang basin increased most significantly.