以沧州和衡水实验站为华北平原地下水浅埋区典型区,利用3 a土壤水负压和地下水观测数据,研究了不同年份和土壤质地土壤水分动态。土壤水分数据表明,平水年或丰水年后的枯水年土壤水分从表层到深层为增长型趋势,枯水年为增长—减小—增长趋势;在土壤非均值条件下(沧州),土壤水分具有补给和消耗的季节性变化,而土壤均质条件下(衡水),无明显季节性变化。时间序列分析结果表明,平水年或丰水年沧州实验点土壤浅层(100 cm以上)和深层(100 cm以下)具有明显差异,从上到下土壤水分更加稳定,衡水实验点无明显差异性;枯水年两实验站浅层和深层差异性更小。土壤质地在降水和土壤水以及地下水的响应关系方面具有显著作用。

The typical shallow groundwater areas of Cangzhou and Hengshui experimental sites were selected and the observed soil water potential and groundwater data from 2004 to 2006 were used to study the soil moisture dynamics with different soil textures. The temporal and special distributions of soil moisture show that soil moisture in the soil profile increases from top to down depth in normal year or in dry year after rainy year and it increases, then decreases and increases in dry year. At Cangzhou site, where soil texture is composed of sand loam and silt loam with good vegetation cover, the soil moisture displays seasonal dynamics of storing moisture period and missing moisture period. It doesn’t show the seasonal dynamics at Hengshui site with homogeneous sand loam and scarce vegetation. The results of time series analysis show that precipitation is the random event, however, soil moisture and groundwater have high autocorrelation with themselves. There exists a significant difference between the shallow soil above 100 cm depth and the deep soil below 100 cm depth at Cangzhou site in rainy year. And the stability of soil moisture increases from shallow to deep depth. However, the difference between shallow soil depths and deep soil depths is insignificant at Hengshui site. In dry year the difference is smaller than normal or rainy year. Soil texture plays a prominent role in the correlation between precipitation and soil water and between precipitation and groundwater.