中文摘要：

选择塔里木河北源及干流区12个代表气象站1959-2004年的年降水系列资料,采用线性回归、平滑方法和Morlet小波功率谱等分析方法,对比分析了塔里木河北源与其干流两个不同区域降水变化趋势与多尺度特征.趋势分析表明：近46a来,两区域年降水都存在增加的趋势,但北源区增加的幅度要明显大于干流区;两个区域在1986年前后,降水增加更趋明显.多尺度分析显示,两区域年降水存在集中于2～8a尺度带上的显著周期.其中,北源区域年降水尺度较为分散,大部分站点年降水集中在2～4a尺度带上,准5a～准8a尺度上也有少量分布;干流区域则主要集中于准3a尺度上.另外,由于时间序列长度的限制和其它不确定因素的影响,两区域部分站点检测出的16a以上的年代际尺度不显著.

英文摘要：

As a part of the Tarim Basin,the north source area and trunk area of the Tarim River is the major eco-agriculture area in the southern part of Xinjiang Uygur Autonomous Region. In the end of the last century,a lot of ecological and environmental issues,e.g.,shortage of the water resources,shrinkage of the forest area,and dried up of the end lake,etc.,occurred in the areas. Recently,these issues have attracted serious attention of scholars,local people and government officials. It is believed that these issues are results of partly changes in climatic and hydrological situation and especially enhancement of local human activities. Many research works have been conducted on climate change and its impacts on local eco-environment. However,they only focused on the precipitation and temperature changes in the whole Tarim Basin. More detailed information about the multi-scale characteristics of precipitation variation in a smaller area,especially in the source area of the Tarim River,has not been thoroughly studied based on robust analysis methods. What mentioned above is the main motivation of the present research. In this paper,the variation of annual precipitation is analyzed by using simple linear regression,smoothing method and Morlet wavelet power spectrum analysis,based on annual precipitation data from 1959 to 2004 observed at twelve meteorological stations,i.e.,Aheqi,Baicheng,Akesu,Alaer,Bayinbuluke,Baluntai,Luntai,Yanqi,Kuche,Kuerle,Tieganlike,Ruoqiang in the north source area and trunk area of the Tarim River,in which the first nine stations represent the region of the north source area and the rest represent the trunk area of the river. Simple linear regression and smoothing method are used to describe the changing tendency of annual precipitation,and the Morlet wavelet power spectrum analysis is used to detect the characteristics of cycles in precipitation in the two areas. The results show that annual precipitation of the two areas has increased since 1986,which may be an indicator of the turning of clima