质地对土壤热性质的影响研究

Influence of soil textures on the thermal properties

土壤热性质是水热迁移研究中的重要参数之一。根据非稳态条件下热流方程的差分解和实测土壤温度资料计算了不同质地土壤的热扩散率 ,并得出了质地影响下的土壤导热率关系式。研究结果表明 ,对特定土壤而言 ,土壤导热率与含水率之间可建立幂函数关系 ;砂粒、粉粒和粘粒含量对土壤热性质有不同程度的影响 ;不同质地土壤的热性质与土壤水吸力之间存在良好的定量关系 ;此外 ,含盐土壤的导热率可表示为浓度的幂函数关系。

Thermal diffusivities of different texture soils were calculated according to measured temperature data and different solutions of heat flow equation in non steady condition, and then, the relationships between thermal conductivities and water content for three textures were analyzed. The results have shown that to certain soil, the relationships between thermal conductivities and water content can be expressed by power function. Meanwhile, the particle content of sand, silt, and clay plays different roles in soil thermal properties, soil thermal parameters can be quantified by soil water suction, and soil thermal conductivity can be expressed by power function of soil salt concentration.