利用柽柳年轮资料重建塔里木河下游英苏1958—2006年3月至6月份浅层地下水埋深

在建立1958—2008年塔里木河下游英苏地区刚毛柽柳（Tamarix hispida Willd．）年表的基础上，将STD和RES年表的年轮宽度指数与英苏监测断面的浅层地下水埋深进行相关分析，表明年轮宽度指数与3月至6月份浅层地下水埋深负相关最显著，相关系数为-0．917（P〈0．01）；利用逐步回归分析，重建了塔里木河下游英苏1958—2006年3月至6月份浅层地下水埋深，并用逐一剔除检验法进行了方程稳定性检验，统计检验参数表明估计序列与实测序列较为相近，交叉检验单相关系数达0．945（P〈0．01），残差缩减值RE为0．393，乘积平均值丁为5．258，符号检验超过95％的置信度，说明重建方程稳定可信；对重建序列趋势分析表明，1958—2000年，英苏浅层地下水埋深序列呈波段增加的趋势，在2000年生态输水后有明显变浅趋势，且浅层地下水埋深最浅时期为20世纪50年代，埋深最深时期出现在20世纪90年代；滑动t检验分析表明，3月至6月份英苏浅层地下水埋深在1963年和1973年前后发生了由浅变深的突变，而2001年则是区域浅层地下水埋深由深变浅的起始点。

Reconstruction of Mar.-Jun. Shallow Water Table Depths from 1958 to 2006 in the Lower Reaches of Tarim River,Yengsu by Use of Tamarix hispida Willd.Tree-ring Width Data

Tamarix hispida Willd. is one of the dominant shrubs species in the lower reaches of Tarim River,Yengsu,which has a major function of maintaining weak ecological balance. Based on the principles and methods of dendrochronology,the ring-with Chronology from 1958 to 2008 was developed. To understand the hydrologic response of the radial growth of Tarnariz hispida Willd. , simple correlation analysis was conducted on the STD, RES tree-ring index and shallow water table depths data of Yengsu during four periods. The analysis resuh showed that there was the evident negative correlation （--0. 917） between the STD tree-ring index and the Mar. --Jun. shallow water table depths. The correlation coefficient --0. 917 above 99 percent confidence level was used to reconstruct an shallow water table depths from 1958 to 2006 in the region. Method of ＂Leave-one-out＂ was used to estimate stability of regression function based on statistics between the observed and estimated series. The simple correlation coefficient is 0. 945 above 99 percent confidence level;the positive RE values signified predictive ability of the model and the sign tests for both actual and estimated values were significant at the 95 percent confidence level. For the series of the construction,there was the rise trend in regional shallow water table depths from 1958 to 2000,but the trend was dropped after 2000. Furthermore, the shallowest periods of shallow water table depths appeared in the 1950s,and that the deepest periods occurred mainly in the 1990s. The abrupt change examination indicated that the obvious sudden change were found in 1963,1973 and 2001.