THERMAL CONDUCTIVITY, THERMAL DIFFUSIVITY, AND THERMAL CAPACITY OF SOME NIGERIAN SOILS
THERMAL CONDUCTIVITY, THERMAL DIFFUSIVITY, AND THERMAL CAPACITY OF SOME NIGERIAN SOILS
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DOI：
10.1097/00010694-198501000-00011
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发表时间：
1985-01
期刊：
影响因子：
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通讯作者：
B. Ghuman;R. Lal
中科院分区：
文献类型：
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作者：
B. Ghuman;R. Lal
土壤导热系数随土壤含水率的增加而增大。在所研究的所有水位下，粘性土的导热系数都低于砂质土。在含水率0.02~0.16 cm~3范围内，砂壤土的导热系数为0.37~1.42，砂质粘壤土的导热系数为0.38~1.71，粘性土的导热系数为0.39~0.41mcal/S·cm°C。土壤水分含量较低时，土壤导热系数差异较小，土壤水分含量较高时土壤导热系数差异较小。水洗砂的导热系数并不随含水率的增加而持续增加。含砾石土壤的导热系数低于不含砾石土壤。现场测量的砾石土的导热系数明显低于筛分均匀的实验室土柱的导热系数。砂质或壤质土壤的热扩散率随含水率的增加而增大，达到峰值后随含水率的进一步增加而减小。然而，质地较好的土壤没有表现出明显的热扩散率峰值。对于中粗质地土壤，根据导热系数和扩散系数的实测值计算的体积热容量与根据土壤组分体积分数(按德弗里斯方程)估算的体积热容非常接近，而对于细质土则不是这样。在风干湿润条件下，粘性土一般比砂质土具有更高的热容量。
Thermal conductivity increased with increasing soil water content. Clayey soils had lower thermal conductivity than sandy soils at all water levels studied. Thermal conductivity ranged from 0.37 to 1.42 for sandy loam, from 0.37 to 1.90 for loam, from 0.38 to 1.71 for sandy clay loam, and from 0.39 to 0.41 mcal/s · cm °C for clay soils at water contents from 0.02 to 0.16 cm3 cm-3. Thermal conductivity differences among soils were smaller at lower soil water contents than at higher water contents. Thermal conductivity did not continuously increase with water content for the washed sand. Soil containing gravel had lower thermal conductivity than gravel-free soil. Thermal conductivity for a gravelly soil measured in situ was appreciably lower than that of the sieved and homogeneous laboratory soil columns. Thermal diffusivity of sandy or loamy soils increased with water content to the peak and then decreased with further increase in water content. Soils of fine texture, however, did not exhibit a distinct thermal diffusivity peak. Volumetric heat capacity calculated from measured values of thermal conductivity and diffusivity agreed closely with those estimated from volume fractions of soil components (by the de Vries equation) for coarse- to medium-textured soils, but not for fine-textured soils. At air-dry wetness, clayey soils generally had higher thermal capacity than sandy soils.