中文摘要：

采用新疆北部伊犁、乌鲁木齐河、昌吉、哈密和阿勒泰建立的树轮年表,重建了北疆地区1543-2001年年降水量序列.结果表明：重建序列具有明显的低频变化特征,其间,多雨期为1557-1591年,1620-1696年,1734-1757年,1784-1807年,1868-1906年,1935-1962年和1981-2001年;少雨期为1592-1619年,1697-1733年,1758-1783年,1808-1867年,1907-1934年和1963-1980年.该地区的年降水量存在40-70 a显著周期变化特征,同时200 a左右的周期变化特征也较为明显,且不同历史时期的周期变化特征存在明显差异.突变检验表明,均值突变尺度在50-100 a尺度上更为明显,公元1613-1643年,1731-1792年的突变表现为年降水量的增加,而公元1669-1712年的突变则表现为年降水量的减少;方差突变则以18世纪80年代最为明显.

英文摘要：

In this study,the annual precipitation series from July of last year to June since A.D.1543 in North Xinjiang Region are reconstructed using tree ring chronologies.The reconstructed series are analyzed with statistical methods.It is found that the pluvial periods of low-frequency were AD 1557-1591,1620-1696,1734-1757,1784-1807,1868-1906,1935-1962 and 1981-2001,and the drought periods were 1592-1619,1697-1733,1758-1783,1808-1867,1907-1934 and 1963-1980.The periodic cycles from forty years to seventy years are significant,and a quasi-200-year cycle can be seen during the whole time period（A.D.1543-2001）.The periodic statistical characteristics are different in different historic phases.Abrupt changes are also detected in the annual precipitation series by the scanning t test,the scanning F test and the scanning Lepage test methods.It is found that the abrupt change with 50-100 years time scale was more obvious.There were three time phases with abrupt changes of average value,among them,AD 1613-1643 and 1731-1792 were two annual precipitation abruptly increasing phases,and 1669-1712 was one annual precipitation abruptly decreasing phase.The analysis of abrupt changes of variance of more than 100 years time scale shows that the abrupt change of variance of lower frequency decreased during A.D.1650-1820,with a more pronounced phase in the 1780s.