温度对土壤水分运动基本参数的影响
Effect of temperature on soil moisture parameters
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摘要: 为探讨土壤温度变化对土壤中水分运动过程和运动参数影响机理,在室内实验的基础上结合理论探讨,对不同温度条件下实验土壤的水分特征曲线、导水率、扩散率和比水容量等土壤水分运动基本参数的温度效应进行了研究分析.结果表明:土壤温度对土壤水分性质及土壤结构性质影响显著,二者共同作用使得土壤水分运动过程发生改变,且其影响效应可通过土壤水分动力学参数的温度效应进行定量描述;温度变化对土壤水分性质的影响主要造成土壤中水分动能和势能的改变,对土壤结构性的改变主要作用于土壤水分的势能;不同质地土壤受温度变化影响具有明显差异;砂性轻质土壤,土壤水分运动过程中可忽略温度变化对其结构造成的影响,但粘粒含量较多的粘重土壤则应予以考虑.Abstract: In order to understand the effect of temperature on soil moisture movement and dynamic parameters, a combined study of laboratory experiments and theoretical analysis is conducted to examine the variation of soil moisture movement parameters due to temperature changes.The study involves the soil moisture retention curve, the hydraulic conductivity, the soil moisture diffusivity and the specific moisture capacity.Results show that soil temperature has a significant effect on soil moisture characteristics and soil structures.The effect of temperature variation can be quantified and described by examining the changes in soil moisture dynamic parameters.The effect of temperature changes on soil moisture characteristics is mainly through altering the kinetic energy and potential energy of the moisture, while on soil structure is mainly reflected in the potential energy of the moisture.Additionally, there has been a noticeable variation of the effect for different soils.The temperature effect on soil moisture movement can be neglectable for sandy soils,for clay soils;however,the opposite is true.