文献类型：期刊文献

英文题名：Estimating the components of apparent thermal conductivity of soils at various water contents and temperatures

作者：Lu, Sen[1,2] Ren, Tusheng[3] Horton, Robert[4]

第一作者：陆森;Lu, Sen

通信作者：Ren, TS[1]

机构：[1]Chinese Acad Forestry, Res Inst Forestry, Key Lab Tree Breeding & Cultivat State Forestry A, Beijing 100091, Peoples R China;[2]Nanjing Forestry Univ, Coinnovat Ctr Sustaintable Forestry Southern Chin, Nanjing 210037, Peoples R China;[3]China Agr Univ, Dept Soil & Water, 2 Yuan Ming Yuan Xi Lu, Beijing 100193, Peoples R China;[4]Iowa State Univ, Dept Agron, Ames, IA 50011 USA

年份：2020

卷号：376

外文期刊名：GEODERMA

收录：;EI(收录号：20202508852147);Scopus(收录号：2-s2.0-85086598527);WOS:【SCI-EXPANDED(收录号:WOS:000558138300027)】；

基金：The authors would like to thank the editor and anonymous reviewers for helpful suggestions in improving the manuscript. We also thank Dr. Eng Giap Goh for his technical assistance. This research was supported by the Natural Science Foundation of China (No. 41877019, No. 41371240) and the Fundamental Research Funds of CAF (No. CAFYBB2019GC001-1).

语种：英文

外文关键词：Soil thermal conductivty; Vapor transfer; Heat conduction; Transient method

摘要：Soil thermal conductivity is an important parameter for estimating soil heat flux and soil thermal regime. Knowledge on the components of apparent soil thermal conductivity (lambda) across various water contents (theta) and temperatures is important to accurately understand soil heat transfer mechanisms. In this study, soil thermal conductivity was measured for sandy loam and silty clay soils at various temperatures and air pressures using a transient method. Four components of lambda, namely, heat conduction, latent heat transfer by water vapor diffusion, sensible heat transfer by liquid water, and sensible heat transfer by water vapor diffusion were quantified. Results showed that in uniform soils, the magnitudes of sensible heat transfers by liquid water and water vapor were negligible during these transient measurements. The contribution of latent heat transfer through vapor diffusion to total heat transfer increased as temperature increased, and the peak value occurred at an intermediate water content. The water content at which the maximum vapor diffusion occurred varied with soil texture. In addition to the four calculated components, a significant residual contribution to lambda caused by an unidentified vapor transfer mechanism was observed between 3.5 degrees C and 81 degrees C. For example, calculations indicated that approximately 66% of the sandy loam lambda at theta=0.11 m(3) m(-3) was caused by an unidentified vapor transfer mechanism at 81 degrees C. This extra contribution by vapor transfer could be explained either as enhanced vapor diffusion or by an advection mechanism. Further investigation is needed to clarify whether enhanced diffusion or advection is occurring in unsaturated soils.