采用青海两个树木年轮年表重建局地过去降水的初步分析

本文依据青海乌兰、班玛两个经过精确定年的树木年轮年表，通过响应函数计算，求得逐月的气候因素对轮宽生长的贡献。在贡献显著的时区内，经由相关计算确立最佳重建时段，选取预报因子，再用逐步回归方法建立方程来重建过去气候。分析表明在重建时段内的两地降水变化，均有明显的多雨期和少雨期，同时存在显著的周期现象。

Utilizing Two Qinghai Tree-ring Chronologies to Reconstruct and Analyze Local Historical Precipitation

In this paper, the two precisely crossdated tree-ring chronologies established in Qinghai Province in Northwestern China were used. The weights of monthly climatic factors to the growth of ring width were obtained by calculating the response function. From these months which had significant weights, the best reconstructing period was set by calculating correlation coefficients between tree ring indices and various combination of season climatic factors. Then we use stepwise multiple regression method to reconstruct the historical climate. By analyzing the two local recon strutted precipitation series, we discovered that there were obviously wet periods, drought periods and rainfall periodic variation