黄土丘陵区人工油松林地土壤水分动态的时间序列分析

Time Series Analysis of Soil Moisture Storage Dynamic Change in the Chinese Pine Forest Land in Hilly Region of the Loess Plateau

利用时间序列分析方法研究了黄土丘陵区人工油松林地土壤水分序列和降水序列之间的关系。在黄土丘陵区,降水时间序列不存在自相关关系,相反土壤贮水量之间存在自相关关系;这说明了前期降水对后期降水没有影响,而前期土壤含水量的高低影响了后期含水量的多少。降水时间序列与人工油松林地0～80cm土层总贮水量序列之间存在相关关系,同时油松林地贮水量与降水时间序列相比表现出1个滞后时间距(1月),说明贮水量主要受当月和前一个月降水的影响。对于上部三个层次(0～10cm,10～20cm,20～40cm)的贮水动态与降水时间序列相关;而20cm以下的土层,与一个滞后时间距的降水时间序列相关系数增大;说明20cm以上土层的贮水量主要受当月降水的影响,20cm以下土层贮水量与当月和前一个月的降水有关。当月降水可以补充到40cm深土层。

The relationships between precipitation and soil moisture storage storage dynamic change in Chinese pine forest land in hilly and gully region in the Loess Plateau were researched by using time series analysis method. There is no self-cooretivity for precipitation time series,but soil moisture storage time series has this relation. These showed the former precipitation has no effect to next, but the amount of former soil moiture storage has markble effects to next phase soil moisture storage. There is correlation between precipitation time series and total soil moisture storage changes in the Chinese pine forest land (depth 0～80cm), at same time, there is a delay time for total soil moisture storage comparison with precipitation series. That showed the total soil moisture storage was mainly affected by precipitation among the former and this months. The soil moisture storages among the upper 3 layer(0～10 cm,10～20 cm,20～40 cm)were correlation with precipitation time series, but there exist a delay time between precipitation series with moisture changes under the 20cm depths. The soil moisture storage above 20cm was mainly affected by precipitation in this month, and the soil moisture storage under 20cm were mainly affected by precipitation among the former and this months. The storage moisture can be supplied to depth 40cm in a month through precipitation.