中文摘要：

为探讨石家庄市栾城区（以下简称栾城区）农田土壤含水量的长期演变规律和机理,采用重标极差分析法计算2002—2008年栾城区深度为10 cm、80 cm和150 cm土壤含水量时间序列的Hurst指数及分形维数。结果表明：深度为10 cm、80 cm和150 cm土壤含水量时间序列的Hurst指数分别是0.738、0.877、0.953,均大于0.5,表明不同层次土壤含水量变化存在着趋势性成分;分形维数的数值分别为1.262、1.123、1.047,表征了土壤含水量波动幅度随着土壤深度的增加而减小的趋势,与实际观测结果一致。

英文摘要：

To investigate the long-term evolution law and mechanisms of soil moisture content in farmlands of Luancheng District in Shijiazhuang City,the Hurst indices and fractal dimension of soil moisture time series（ 2002 to 2008） at depths of 10 cm,80 cm,and 150 cm were calculated by rescaled range analysis. Results show that the Hurst indices of soil moisture at 10 cm,80 cm,and 150 cm are 0. 738,0. 877,and 0. 953,respectively,all greater than 0. 5,indicating some trends of variations of soil moisture at different depths; and the values of fractal dimension are 1. 262,1. 123,and 1. 047,respectively,indicating a decreasing trend of the fluctuation amplitude of soil moisture content with the increase of depth,which is consistent with the observed results.