汉江流域1951——2003年降水气温时空变化趋势分析

TEMPORAL AND SPATIAL TREND IN THE PRECIPITATION AND TEMPERATURE FROM 1951 TO 2003 IN THE HANJIANG BASIN

利用Mann-Kendall检验方法和空间插值方法，分析了1951～2003年汉江流域年和春、夏、秋、冬四季降水和气温变化趋势的时空分布，并重点分析了丹江口水库上游年降水、年平均气温和北半球气温的变化趋势及相互间的联系。分析发现，在显著性水平a-0．1上，近50年来汉江流域大部分地区降水没有明显的变化趋势，气温呈上升趋势。丹江口水库上游降水在1991年发生突变，从20世纪80年代多雨期进入90年代少雨期，80年代平均降水比1951～2003年多年平均降水多9．7％，90年代平均降水比多年平均降水少11．6％；上游平均气温90年代比多年平均气温高0．2℃，而同期北半球的平均气温也比多年平均高了0．3℃，上游气温同北半球气温同步上升，而上游降水变化受北半球气温升高的影响不断减少，两者之间存在反相关系。分析成果有助于进一步研究气候变化对汉江流域水资源和防洪安全的影响，也将为南水北调中线工程的顺利实施提供科学依据。

The annual and seasonal precipitation and temperature from 1951 to 2003 in the Hanjiang Basin were analyzed to obtain the temporal and spatial trend by using the Mann Kendall trend test and the spatial interpolation method. The precipitation, temperature in the upper Danjiangkou reservoir basin and the temperature in the northern hemisphere were compared and analyzed to obtain the relationship between them. The results indicate that at the a=0.1 significance level there is no trend of the precipitation in most parts of the Hanjiang basin, but the trend of the temperature is upward. In the upper basin the precipitati on had a climate jump in 1991 when the precipitation changed from the wet period in 1980s to the dry peri od in 1990s. The average precipitation in 1980s is 9.70% more than the mean value of 1951～2003, while in 1990s is 11.60% less than that value. The average temperature in 1990s is 0.3℃higher than the mean val ue of 1951～2003, in the same period the average temperature of the northern hemisphere is 0.3℃ higher than the mean value of 1951～2003. The temperature in the upper basin is increased, while the precipitation is decreased as the temperature increases in the northern hemisphere. The results will help in further studying the impact of the climate change on water resources and the flood prevention in the Hanjiang Basin. It will also provide scientific references for the middle route of south-to-north water diversion project in China.