根据2006年采自特克斯河流域6个采样点的树轮样本研制的树轮宽度年表与气象资料,通过相关普查发现,特克斯河流域树轮标准化年表与上年7月至当年6月的降水存在显著的正相关,最高单相关系数为0.727。用库尔克尔也灭,小白代的树轮宽度标准化年表序列,可较好地重建该地区最近236a的降水序列,方差解释量达54%,并通过交叉检验表明重建结果是稳定可靠的。近236a,特克斯河流域上年7月至当年6月降水经历了8个偏湿阶段和8个偏干阶段,同时重建降水序列具有10.3a、7.5a、6.0a、3.0a、2.1a的变化准周期,并在1790年,1911年,1929年,1974年发生过降水突变。采用毛毛虫-奇异谱分析法(Caterpillar-ssa)对该地区未来20a的降水的自然变化进行预测。结果表明,21世纪的最初几年降水量将延续20世纪90年代以来增加的趋势,之后出现下降,并在2013~2016年前后最低值出现。
The tree-ring chronologies were established according to samples from the Tekes River Basin.Single correlation calculation indicated that the correlations were significant between the tree-ring chronologies and the previous July through present year's June total precipitation,and the maximum correlation coefficient was 0.727.Using XBDt(STD)、KRKt(STD)tree-ring chronology series,the precipitation series during the last 236 years was reconstructed,with an explained variance of 54%.The equation was stable by leave-one-out cross validation.Analyzing the precipitation series,we found out that:(1)During the last 236 years,the precipitation of Tekes River Basin had 8 wet periods and 8 dry periods;(2)The reconstructed precipitation in the Tekes River Basin during the last 236 years had significant periods of 10.3,7.5,6.0,3.0 and 2.1 years.The abrupt change of precipitation occurred in 1790,1911,1929 and 1974.Using Caterpillar-SSA analysis method,through the process of embedding,singular value decomposition,grouping and diagonal averaging,The trend of precipitation series for the next 20 years in the Tekes River Basin is forecasted.The results show an increasing trend from 2000 to 2006.In the subsequent decade the precipitation should reduce quickly,and it will reach a minimum near 2013 to 2016.