A generalized relationship between thermal conductivity and matric suction of soils

作   者：陆森，卢奕丽，彭薇，巨兆强，任图生
期刊名称：Geoderma
影响因子：3.740
卷 期 号：337
页     码：491-497
关键词：Soil thermal conductivity Matric suction Prediction error Soil water retention curve
论文摘要：
The soil thermal conductivity (λ) and matric suction of soil water (h, the negative of matric potential) relationship
has been widely used in land surface models for estimating soil temperature and heat flux following
the McCumber and Pielke (1981, MP81) λ-h model. However, few datasets are available for evaluating the
accuracy and feasibility of the MP81 λ-h model under various soil and moisture conditions. In this study, we
developed a new λ-h model and compared its performance with that of the MP81 model using measurements on
18 soils with a wide range of textures, water contents and bulk densities. The heat pulse technique was used to
measure λ, and the suction table, micro-tensiometers, pressure plate device, and the dew point potentiometer
were applied to obtain soil water retention curves at the appropriate suction ranges. In the range of pF (the
common logarithm of h in cm)≤3, the λ-h relationships were highly nonlinear and varied strongly with soil
texture and bulk density. In the dry range (i.e., pF > 3), there existed a universal λ-h relationship for all soil
textures and bulk densities, and an exponential function was established to describe the relationship.
Independent evaluations using λ-h data on five intact soil samples showed that the new model produced accurate
λ data from pF values with root mean square errors (RMSE) with the range of 0.03–0.18Wm−1 K−1. While,
large errors (RMSEs within 0.17–0.36Wm−1 K−1) were observed with λ estimates from the MP81 model.