南北方粘质土壤密度对土壤水分特征van Genuchten模型的影响研究

Influence of Bulk Density Changes on Soil Water Characteristics van Genuchten Model

以南北方典型粘质土壤红壤和塿土为试验土样,通过水平入渗试验进行了土壤密度变化对土壤水分特征van Genuchten模型参数的影响研究。研究结果表明,特征湿润长度、吸力、饱和含水量、滞留含水量、饱和导水率均随土壤密度增加而减小;土壤水分特征van Genuchten模型参数n随着土壤密度的增加而递增,而参数α随着土壤密度的增加而减小,与土壤密度成反比;参数n和参数α随土壤密度变化关系可用幂函数来描述。为建立吸力、土壤密度、质量含水率三变量的土壤水分特征曲面提供新的途径,有助于完善土壤水动力学理论。

Red soil and Loutu soil were chosen as experimental samples,which were clay soils in south and north regions.Effects of bulk density changes on water characteristics van Genuchten model were studied by horizontal infiltration.The results showed that characteristic wetting length,suction,saturated water content,residual moisture content and saturated hydraulic conductivity decreased with increase of bulk density.Parameter n gradually increased and parameter α yet declined when bulk density increased.Relationship between parameters α,n and bulk density could be described quantitatively by power function.This will provide new way for building soil water characteristics surface with three variables of bulk density,bulk density and gravity content and make soil hydrology theory perfect.