Apparent soil thermal diffusivity, a case study: HAPEX-Sahel experiment
Apparent soil thermal diffusivity, a case study: HAPEX-Sahel experiment
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DOI：
10.1016/0168-1923(95)02323-2
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发表时间：
1996-11
影响因子：
6.2
通讯作者：
A. Silans;B. Monteny;J. Lhomme
中科院分区：
文献类型：
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作者：
A. Silans;B. Monteny;J. Lhomme
在本文中，我们测定了HAPEX-SAHEL实验中致密沙土的表观热扩散率。对现有的几种方法进行了比较。选择了两个温度数据集。在第一种情况下，稳定周期性的假设成立，而在第二种情况下，则不成立。在这两种情况下，我们比较了假设土壤热性质垂直均匀的方法和基于热扩散率垂直不均匀的NHS方法。用这两组数据得到的结果表明，热物性在垂直方向上是不均匀的。结果表明，当稳态周期假设不成立时，NHS方法是不适用的。在这种情况下，当温度波动模式发生突变时，就像经常发生在萨赫勒地区的雨前或雨后一样，必须使用基于Lapalce变换的方法，该方法带有对初始温度分布(CLTM)的不均匀的校正因子。当满足定常周期假设时，调和(HM)方法和CUM方法都比NHS方法得到的热扩散率值稍大。
In this paper, we determine the apparent soil thermal diffusivity of a dense sandy soil of the HAPEX-Sahel experiment. Several current methods are compared. Two temperature data sets are chosen. In the first, the assumption of steady periodicity is fulfilled and in the second, it is not. In both cases, we compare methods which assume a vertical homogeneity of the soil thermal properties with the NHS method which is based on the vertical inhomogeneity of the thermal diffusivity. Results obtained with both sets of data show that thermal properties are not homogeneous vertically. It is shown that the NHS method is not applicable when the steady periodicity assumption is not valid. In this case, when abrupt change in the temperature wave pattern occurs, as frequently happens in the Sahel just before or just after a rain, a method based on the Lapalce Transform with a corrective factor for the non uniformity of the initial temperature profile (CLTM) must be used. When the steady periodicity assumption is fulfilled, both the Harmonic (HM) and the CUM methods lead to somewhat greater values of the thermal diffusivity than the NHS method.