上层土壤初始含水率对层状结构土壤中指流水分入渗的影响

为探明影响指流入渗特性的主要因素,通过室内物理模拟试验研究不同上层土壤初始质量含水率对层状结构土壤中指流水分运移的影响.结果表明:湿润锋到达指流层的转折时间与上层土壤初始含水率的相关性较高,且呈对数关系；分别运用分段函数模型和连续函数模型对累积入渗量与时间的关系进行拟合,发现运用分段函数模型拟合的结果虽整体与实测值相关性较高,但是该模型在进行分段拟合时,由于分段点处的不连续性,与实际中层状结构土壤水分入渗不一致,而连续函数模型随着入渗时间的延长,模拟结果越接近实测值,且连续函数模型符合实际中层状结构土壤水分入渗的连续性,因此,连续函数模型适用于长历时的水分入渗过程.

Effect of upper initial moisture content on water infiltration of the finger flow

This paper described the effect of upper initial moisture content on water infiltration of the finger flow.The results showe that there was a higher logarithmic correlation between the turning time of wetting front reaching to the finger flow layer with the initial moisture content of the upper soil.Both models of piecewise function and the continuous function could be used to fit the relationship between cumulative-infiltration and time.It was found that the accuracy of Piecewise function model was higher.Since this model is discontinuous on the subsection,it was inconsistent with the water infiltration in the layered structure of soil.With infiltration duration,the simulated values of the continuous function model was closer to the measured ones.The continuous function model was in consistent with the water infiltration in the layered structure of soil and suitable to simulate the long-term infiltration process.